    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.lang3;
    018
    019import java.lang.reflect.Method;
    020import java.lang.reflect.Modifier;
    021import java.util.ArrayList;
    022import java.util.Arrays;
    023import java.util.Collections;
    024import java.util.Comparator;
    025import java.util.HashMap;
    026import java.util.HashSet;
    027import java.util.Iterator;
    028import java.util.LinkedHashSet;
    029import java.util.List;
    030import java.util.Map;
    031import java.util.Objects;
    032import java.util.Set;
    033import java.util.stream.Collectors;
    034
    035import org.apache.commons.lang3.mutable.MutableObject;
    036
    037/**
    038 * Operates on classes without using reflection.
    039 *
    040 * <p>
    041 * This class handles invalid {@code null} inputs as best it can. Each method documents its behavior in more detail.
    042 * </p>
    043 *
    044 * <p>
    045 * The notion of a {@code canonical name} includes the human readable name for the type, for example {@code int[]}. The
    046 * non-canonical method variants work with the JVM names, such as {@code [I}.
    047 * </p>
    048 *
    049 * @since 2.0
    050 */
    051public class ClassUtils {
    052
    053    /**
    054     * Inclusivity literals for {@link #hierarchy(Class, Interfaces)}.
    055     *
    056     * @since 3.2
    057     */
    058    public enum Interfaces {
    059
    060        /** Includes interfaces. */
    061        INCLUDE,
    062
    063        /** Excludes interfaces. */
    064        EXCLUDE
    065    }
    066
    067    private static final Comparator<Class<?>> COMPARATOR = (o1, o2) -> Objects.compare(getName(o1), getName(o2), String::compareTo);
    068
    069    /**
    070     * The package separator character: {@code '&#x2e;' == {@value}}.
    071     */
    072    public static final char PACKAGE_SEPARATOR_CHAR = '.';
    073
    074    /**
    075     * The package separator String: {@code "&#x2e;"}.
    076     */
    077    public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);
    078
    079    /**
    080     * The inner class separator character: {@code '$' == {@value}}.
    081     */
    082    public static final char INNER_CLASS_SEPARATOR_CHAR = '$';
    083
    084    /**
    085     * The inner class separator String: {@code "$"}.
    086     */
    087    public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);
    088
    089    /**
    090     * Maps names of primitives to their corresponding primitive {@link Class}es.
    091     */
    092    private static final Map<String, Class<?>> namePrimitiveMap = new HashMap<>();
    093
    094    static {
    095        namePrimitiveMap.put(Boolean.TYPE.getSimpleName(), Boolean.TYPE);
    096        namePrimitiveMap.put(Byte.TYPE.getSimpleName(), Byte.TYPE);
    097        namePrimitiveMap.put(Character.TYPE.getSimpleName(), Character.TYPE);
    098        namePrimitiveMap.put(Double.TYPE.getSimpleName(), Double.TYPE);
    099        namePrimitiveMap.put(Float.TYPE.getSimpleName(), Float.TYPE);
    100        namePrimitiveMap.put(Integer.TYPE.getSimpleName(), Integer.TYPE);
    101        namePrimitiveMap.put(Long.TYPE.getSimpleName(), Long.TYPE);
    102        namePrimitiveMap.put(Short.TYPE.getSimpleName(), Short.TYPE);
    103        namePrimitiveMap.put(Void.TYPE.getSimpleName(), Void.TYPE);
    104    }
    105
    106    /**
    107     * Maps primitive {@link Class}es to their corresponding wrapper {@link Class}.
    108     */
    109    private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<>();
    110
    111    static {
    112        primitiveWrapperMap.put(Boolean.TYPE, Boolean.class);
    113        primitiveWrapperMap.put(Byte.TYPE, Byte.class);
    114        primitiveWrapperMap.put(Character.TYPE, Character.class);
    115        primitiveWrapperMap.put(Short.TYPE, Short.class);
    116        primitiveWrapperMap.put(Integer.TYPE, Integer.class);
    117        primitiveWrapperMap.put(Long.TYPE, Long.class);
    118        primitiveWrapperMap.put(Double.TYPE, Double.class);
    119        primitiveWrapperMap.put(Float.TYPE, Float.class);
    120        primitiveWrapperMap.put(Void.TYPE, Void.TYPE);
    121    }
    122
    123    /**
    124     * Maps wrapper {@link Class}es to their corresponding primitive types.
    125     */
    126    private static final Map<Class<?>, Class<?>> wrapperPrimitiveMap = new HashMap<>();
    127
    128    static {
    129        primitiveWrapperMap.forEach((primitiveClass, wrapperClass) -> {
    130            if (!primitiveClass.equals(wrapperClass)) {
    131                wrapperPrimitiveMap.put(wrapperClass, primitiveClass);
    132            }
    133        });
    134    }
    135
    136    /**
    137     * Maps a primitive class name to its corresponding abbreviation used in array class names.
    138     */
    139    private static final Map<String, String> abbreviationMap;
    140
    141    /**
    142     * Maps an abbreviation used in array class names to corresponding primitive class name.
    143     */
    144    private static final Map<String, String> reverseAbbreviationMap;
    145
    146    /** Feed abbreviation maps. */
    147    static {
    148        final Map<String, String> map = new HashMap<>();
    149        map.put("int", "I");
    150        map.put("boolean", "Z");
    151        map.put("float", "F");
    152        map.put("long", "J");
    153        map.put("short", "S");
    154        map.put("byte", "B");
    155        map.put("double", "D");
    156        map.put("char", "C");
    157        abbreviationMap = Collections.unmodifiableMap(map);
    158        reverseAbbreviationMap = Collections.unmodifiableMap(map.entrySet().stream().collect(Collectors.toMap(Map.Entry::getValue, Map.Entry::getKey)));
    159    }
    160
    161    /**
    162     * Gets the class comparator, comparing by class name.
    163     *
    164     * @return the class comparator.
    165     * @since 3.13.0
    166     */
    167    public static Comparator<Class<?>> comparator() {
    168        return COMPARATOR;
    169    }
    170
    171    /**
    172     * Given a {@link List} of {@link Class} objects, this method converts them into class names.
    173     *
    174     * <p>
    175     * A new {@link List} is returned. {@code null} objects will be copied into the returned list as {@code null}.
    176     * </p>
    177     *
    178     * @param classes the classes to change
    179     * @return a {@link List} of class names corresponding to the Class objects, {@code null} if null input
    180     * @throws ClassCastException if {@code classes} contains a non-{@link Class} entry
    181     */
    182    public static List<String> convertClassesToClassNames(final List<Class<?>> classes) {
    183        return classes == null ? null : classes.stream().map(e -> getName(e, null)).collect(Collectors.toList());
    184    }
    185
    186    /**
    187     * Given a {@link List} of class names, this method converts them into classes.
    188     *
    189     * <p>
    190     * A new {@link List} is returned. If the class name cannot be found, {@code null} is stored in the {@link List}. If the
    191     * class name in the {@link List} is {@code null}, {@code null} is stored in the output {@link List}.
    192     * </p>
    193     *
    194     * @param classNames the classNames to change
    195     * @return a {@link List} of Class objects corresponding to the class names, {@code null} if null input
    196     * @throws ClassCastException if classNames contains a non String entry
    197     */
    198    public static List<Class<?>> convertClassNamesToClasses(final List<String> classNames) {
    199        if (classNames == null) {
    200            return null;
    201        }
    202        final List<Class<?>> classes = new ArrayList<>(classNames.size());
    203        classNames.forEach(className -> {
    204            try {
    205                classes.add(Class.forName(className));
    206            } catch (final Exception ex) {
    207                classes.add(null);
    208            }
    209        });
    210        return classes;
    211    }
    212
    213    /**
    214     * Gets the abbreviated name of a {@link Class}.
    215     *
    216     * @param cls the class to get the abbreviated name for, may be {@code null}
    217     * @param lengthHint the desired length of the abbreviated name
    218     * @return the abbreviated name or an empty string
    219     * @throws IllegalArgumentException if len &lt;= 0
    220     * @see #getAbbreviatedName(String, int)
    221     * @since 3.4
    222     */
    223    public static String getAbbreviatedName(final Class<?> cls, final int lengthHint) {
    224        if (cls == null) {
    225            return StringUtils.EMPTY;
    226        }
    227        return getAbbreviatedName(cls.getName(), lengthHint);
    228    }
    229
    230    /**
    231     * Gets the abbreviated class name from a {@link String}.
    232     *
    233     * <p>
    234     * The string passed in is assumed to be a class name - it is not checked.
    235     * </p>
    236     *
    237     * <p>
    238     * The abbreviation algorithm will shorten the class name, usually without significant loss of meaning.
    239     * </p>
    240     *
    241     * <p>
    242     * The abbreviated class name will always include the complete package hierarchy. If enough space is available,
    243     * rightmost sub-packages will be displayed in full length. The abbreviated package names will be shortened to a single
    244     * character.
    245     * </p>
    246     * <p>
    247     * Only package names are shortened, the class simple name remains untouched. (See examples.)
    248     * </p>
    249     * <p>
    250     * The result will be longer than the desired length only if all the package names shortened to a single character plus
    251     * the class simple name with the separating dots together are longer than the desired length. In other words, when the
    252     * class name cannot be shortened to the desired length.
    253     * </p>
    254     * <p>
    255     * If the class name can be shortened then the final length will be at most {@code lengthHint} characters.
    256     * </p>
    257     * <p>
    258     * If the {@code lengthHint} is zero or negative then the method throws exception. If you want to achieve the shortest
    259     * possible version then use {@code 1} as a {@code lengthHint}.
    260     * </p>
    261     *
    262     * <table>
    263     * <caption>Examples</caption>
    264     * <tr>
    265     * <td>className</td>
    266     * <td>len</td>
    267     * <td>return</td>
    268     * </tr>
    269     * <tr>
    270     * <td>null</td>
    271     * <td>1</td>
    272     * <td>""</td>
    273     * </tr>
    274     * <tr>
    275     * <td>"java.lang.String"</td>
    276     * <td>5</td>
    277     * <td>"j.l.String"</td>
    278     * </tr>
    279     * <tr>
    280     * <td>"java.lang.String"</td>
    281     * <td>15</td>
    282     * <td>"j.lang.String"</td>
    283     * </tr>
    284     * <tr>
    285     * <td>"java.lang.String"</td>
    286     * <td>30</td>
    287     * <td>"java.lang.String"</td>
    288     * </tr>
    289     * <tr>
    290     * <td>"org.apache.commons.lang3.ClassUtils"</td>
    291     * <td>18</td>
    292     * <td>"o.a.c.l.ClassUtils"</td>
    293     * </tr>
    294     * </table>
    295     *
    296     * @param className the className to get the abbreviated name for, may be {@code null}
    297     * @param lengthHint the desired length of the abbreviated name
    298     * @return the abbreviated name or an empty string if the specified class name is {@code null} or empty string. The
    299     *         abbreviated name may be longer than the desired length if it cannot be abbreviated to the desired length.
    300     * @throws IllegalArgumentException if {@code len <= 0}
    301     * @since 3.4
    302     */
    303    public static String getAbbreviatedName(final String className, final int lengthHint) {
    304        if (lengthHint <= 0) {
    305            throw new IllegalArgumentException("len must be > 0");
    306        }
    307        if (className == null) {
    308            return StringUtils.EMPTY;
    309        }
    310        if (className.length() <= lengthHint) {
    311            return className;
    312        }
    313        final char[] abbreviated = className.toCharArray();
    314        int target = 0;
    315        int source = 0;
    316        while (source < abbreviated.length) {
    317            // copy the next part
    318            int runAheadTarget = target;
    319            while (source < abbreviated.length && abbreviated[source] != '.') {
    320                abbreviated[runAheadTarget++] = abbreviated[source++];
    321            }
    322
    323            ++target;
    324            if (useFull(runAheadTarget, source, abbreviated.length, lengthHint) || target > runAheadTarget) {
    325                target = runAheadTarget;
    326            }
    327
    328            // copy the '.' unless it was the last part
    329            if (source < abbreviated.length) {
    330                abbreviated[target++] = abbreviated[source++];
    331            }
    332        }
    333        return new String(abbreviated, 0, target);
    334    }
    335
    336    /**
    337     * Gets a {@link List} of all interfaces implemented by the given class and its superclasses.
    338     *
    339     * <p>
    340     * The order is determined by looking through each interface in turn as declared in the source file and following its
    341     * hierarchy up. Then each superclass is considered in the same way. Later duplicates are ignored, so the order is
    342     * maintained.
    343     * </p>
    344     *
    345     * @param cls the class to look up, may be {@code null}
    346     * @return the {@link List} of interfaces in order, {@code null} if null input
    347     */
    348    public static List<Class<?>> getAllInterfaces(final Class<?> cls) {
    349        if (cls == null) {
    350            return null;
    351        }
    352
    353        final LinkedHashSet<Class<?>> interfacesFound = new LinkedHashSet<>();
    354        getAllInterfaces(cls, interfacesFound);
    355
    356        return new ArrayList<>(interfacesFound);
    357    }
    358
    359    /**
    360     * Gets the interfaces for the specified class.
    361     *
    362     * @param cls the class to look up, may be {@code null}
    363     * @param interfacesFound the {@link Set} of interfaces for the class
    364     */
    365    private static void getAllInterfaces(Class<?> cls, final HashSet<Class<?>> interfacesFound) {
    366        while (cls != null) {
    367            final Class<?>[] interfaces = cls.getInterfaces();
    368
    369            for (final Class<?> i : interfaces) {
    370                if (interfacesFound.add(i)) {
    371                    getAllInterfaces(i, interfacesFound);
    372                }
    373            }
    374
    375            cls = cls.getSuperclass();
    376        }
    377    }
    378
    379    /**
    380     * Gets a {@link List} of superclasses for the given class.
    381     *
    382     * @param cls the class to look up, may be {@code null}
    383     * @return the {@link List} of superclasses in order going up from this one {@code null} if null input
    384     */
    385    public static List<Class<?>> getAllSuperclasses(final Class<?> cls) {
    386        if (cls == null) {
    387            return null;
    388        }
    389        final List<Class<?>> classes = new ArrayList<>();
    390        Class<?> superclass = cls.getSuperclass();
    391        while (superclass != null) {
    392            classes.add(superclass);
    393            superclass = superclass.getSuperclass();
    394        }
    395        return classes;
    396    }
    397
    398    /**
    399     * Gets the canonical class name for a {@link Class}.
    400     *
    401     * @param cls the class for which to get the canonical class name; may be null
    402     * @return the canonical name of the class, or the empty String
    403     * @since 3.7
    404     * @see Class#getCanonicalName()
    405     */
    406    public static String getCanonicalName(final Class<?> cls) {
    407        return getCanonicalName(cls, StringUtils.EMPTY);
    408    }
    409
    410    /**
    411     * Gets the canonical name for a {@link Class}.
    412     *
    413     * @param cls the class for which to get the canonical class name; may be null
    414     * @param valueIfNull the return value if null
    415     * @return the canonical name of the class, or {@code valueIfNull}
    416     * @since 3.7
    417     * @see Class#getCanonicalName()
    418     */
    419    public static String getCanonicalName(final Class<?> cls, final String valueIfNull) {
    420        if (cls == null) {
    421            return valueIfNull;
    422        }
    423        final String canonicalName = cls.getCanonicalName();
    424        return canonicalName == null ? valueIfNull : canonicalName;
    425    }
    426
    427    /**
    428     * Gets the canonical name for an {@link Object}.
    429     *
    430     * @param object the object for which to get the canonical class name; may be null
    431     * @return the canonical name of the object, or the empty String
    432     * @since 3.7
    433     * @see Class#getCanonicalName()
    434     */
    435    public static String getCanonicalName(final Object object) {
    436        return getCanonicalName(object, StringUtils.EMPTY);
    437    }
    438
    439    /**
    440     * Gets the canonical name for an {@link Object}.
    441     *
    442     * @param object the object for which to get the canonical class name; may be null
    443     * @param valueIfNull the return value if null
    444     * @return the canonical name of the object or {@code valueIfNull}
    445     * @since 3.7
    446     * @see Class#getCanonicalName()
    447     */
    448    public static String getCanonicalName(final Object object, final String valueIfNull) {
    449        if (object == null) {
    450            return valueIfNull;
    451        }
    452        final String canonicalName = object.getClass().getCanonicalName();
    453        return canonicalName == null ? valueIfNull : canonicalName;
    454    }
    455
    456    /**
    457     * Converts a given name of class into canonical format. If name of class is not a name of array class it returns
    458     * unchanged name.
    459     *
    460     * <p>
    461     * The method does not change the {@code $} separators in case the class is inner class.
    462     * </p>
    463     *
    464     * <p>
    465     * Example:
    466     * <ul>
    467     * <li>{@code getCanonicalName("[I") = "int[]"}</li>
    468     * <li>{@code getCanonicalName("[Ljava.lang.String;") = "java.lang.String[]"}</li>
    469     * <li>{@code getCanonicalName("java.lang.String") = "java.lang.String"}</li>
    470     * </ul>
    471     * </p>
    472     *
    473     * @param className the name of class
    474     * @return canonical form of class name
    475     * @since 2.4
    476     */
    477    private static String getCanonicalName(String className) {
    478        className = StringUtils.deleteWhitespace(className);
    479        if (className == null) {
    480            return null;
    481        }
    482        int dim = 0;
    483        while (className.startsWith("[")) {
    484            dim++;
    485            className = className.substring(1);
    486        }
    487        if (dim < 1) {
    488            return className;
    489        }
    490        if (className.startsWith("L")) {
    491            className = className.substring(1, className.endsWith(";") ? className.length() - 1 : className.length());
    492        } else if (!className.isEmpty()) {
    493            className = reverseAbbreviationMap.get(className.substring(0, 1));
    494        }
    495        final StringBuilder canonicalClassNameBuffer = new StringBuilder(className);
    496        for (int i = 0; i < dim; i++) {
    497            canonicalClassNameBuffer.append("[]");
    498        }
    499        return canonicalClassNameBuffer.toString();
    500    }
    501
    502    /**
    503     * Returns the (initialized) class represented by {@code className} using the {@code classLoader}. This implementation
    504     * supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    505     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    506     *
    507     * @param classLoader the class loader to use to load the class
    508     * @param className the class name
    509     * @return the class represented by {@code className} using the {@code classLoader}
    510     * @throws NullPointerException if the className is null
    511     * @throws ClassNotFoundException if the class is not found
    512     */
    513    public static Class<?> getClass(final ClassLoader classLoader, final String className) throws ClassNotFoundException {
    514        return getClass(classLoader, className, true);
    515    }
    516
    517    /**
    518     * Returns the class represented by {@code className} using the {@code classLoader}. This implementation supports the
    519     * syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}", and
    520     * "{@code [Ljava.util.Map$Entry;}".
    521     *
    522     * @param classLoader the class loader to use to load the class
    523     * @param className the class name
    524     * @param initialize whether the class must be initialized
    525     * @return the class represented by {@code className} using the {@code classLoader}
    526     * @throws NullPointerException if the className is null
    527     * @throws ClassNotFoundException if the class is not found
    528     */
    529    public static Class<?> getClass(final ClassLoader classLoader, final String className, final boolean initialize) throws ClassNotFoundException {
    530        try {
    531            final Class<?> clazz = getPrimitiveClass(className);
    532            return clazz != null ? clazz : Class.forName(toCanonicalName(className), initialize, classLoader);
    533        } catch (final ClassNotFoundException ex) {
    534            // allow path separators (.) as inner class name separators
    535            final int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    536
    537            if (lastDotIndex != -1) {
    538                try {
    539                    return getClass(classLoader, className.substring(0, lastDotIndex) + INNER_CLASS_SEPARATOR_CHAR + className.substring(lastDotIndex + 1),
    540                        initialize);
    541                } catch (final ClassNotFoundException ignored) {
    542                    // ignore exception
    543                }
    544            }
    545
    546            throw ex;
    547        }
    548    }
    549
    550    /**
    551     * Returns the (initialized) class represented by {@code className} using the current thread's context class loader.
    552     * This implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    553     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    554     *
    555     * @param className the class name
    556     * @return the class represented by {@code className} using the current thread's context class loader
    557     * @throws NullPointerException if the className is null
    558     * @throws ClassNotFoundException if the class is not found
    559     */
    560    public static Class<?> getClass(final String className) throws ClassNotFoundException {
    561        return getClass(className, true);
    562    }
    563
    564    /**
    565     * Returns the class represented by {@code className} using the current thread's context class loader. This
    566     * implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    567     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    568     *
    569     * @param className the class name
    570     * @param initialize whether the class must be initialized
    571     * @return the class represented by {@code className} using the current thread's context class loader
    572     * @throws NullPointerException if the className is null
    573     * @throws ClassNotFoundException if the class is not found
    574     */
    575    public static Class<?> getClass(final String className, final boolean initialize) throws ClassNotFoundException {
    576        final ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
    577        final ClassLoader loader = contextCL == null ? ClassUtils.class.getClassLoader() : contextCL;
    578        return getClass(loader, className, initialize);
    579    }
    580
    581    /**
    582     * Delegates to {@link Class#getComponentType()} using generics.
    583     *
    584     * @param <T> The array class type.
    585     * @param cls A class or null.
    586     * @return The array component type or null.
    587     * @see Class#getComponentType()
    588     * @since 3.13.0
    589     */
    590    @SuppressWarnings("unchecked")
    591    public static <T> Class<T> getComponentType(final Class<T[]> cls) {
    592        return cls == null ? null : (Class<T>) cls.getComponentType();
    593    }
    594
    595    /**
    596     * Null-safe version of {@code cls.getName()}
    597     *
    598     * @param cls the class for which to get the class name; may be null
    599     * @return the class name or the empty string in case the argument is {@code null}
    600     * @since 3.7
    601     * @see Class#getSimpleName()
    602     */
    603    public static String getName(final Class<?> cls) {
    604        return getName(cls, StringUtils.EMPTY);
    605    }
    606
    607    /**
    608     * Null-safe version of {@code cls.getName()}
    609     *
    610     * @param cls the class for which to get the class name; may be null
    611     * @param valueIfNull the return value if the argument {@code cls} is {@code null}
    612     * @return the class name or {@code valueIfNull}
    613     * @since 3.7
    614     * @see Class#getName()
    615     */
    616    public static String getName(final Class<?> cls, final String valueIfNull) {
    617        return cls == null ? valueIfNull : cls.getName();
    618    }
    619
    620    /**
    621     * Null-safe version of {@code object.getClass().getName()}
    622     *
    623     * @param object the object for which to get the class name; may be null
    624     * @return the class name or the empty String
    625     * @since 3.7
    626     * @see Class#getSimpleName()
    627     */
    628    public static String getName(final Object object) {
    629        return getName(object, StringUtils.EMPTY);
    630    }
    631
    632    /**
    633     * Null-safe version of {@code object.getClass().getSimpleName()}
    634     *
    635     * @param object the object for which to get the class name; may be null
    636     * @param valueIfNull the value to return if {@code object} is {@code null}
    637     * @return the class name or {@code valueIfNull}
    638     * @since 3.0
    639     * @see Class#getName()
    640     */
    641    public static String getName(final Object object, final String valueIfNull) {
    642        return object == null ? valueIfNull : object.getClass().getName();
    643    }
    644
    645    /**
    646     * Gets the package name from the canonical name of a {@link Class}.
    647     *
    648     * @param cls the class to get the package name for, may be {@code null}.
    649     * @return the package name or an empty string
    650     * @since 2.4
    651     */
    652    public static String getPackageCanonicalName(final Class<?> cls) {
    653        if (cls == null) {
    654            return StringUtils.EMPTY;
    655        }
    656        return getPackageCanonicalName(cls.getName());
    657    }
    658
    659    /**
    660     * Gets the package name from the class name of an {@link Object}.
    661     *
    662     * @param object the class to get the package name for, may be null
    663     * @param valueIfNull the value to return if null
    664     * @return the package name of the object, or the null value
    665     * @since 2.4
    666     */
    667    public static String getPackageCanonicalName(final Object object, final String valueIfNull) {
    668        if (object == null) {
    669            return valueIfNull;
    670        }
    671        return getPackageCanonicalName(object.getClass().getName());
    672    }
    673
    674    /**
    675     * Gets the package name from the class name.
    676     *
    677     * <p>
    678     * The string passed in is assumed to be a class name - it is not checked.
    679     * </p>
    680     * <p>
    681     * If the class is in the default package, return an empty string.
    682     * </p>
    683     *
    684     * @param name the name to get the package name for, may be {@code null}
    685     * @return the package name or an empty string
    686     * @since 2.4
    687     */
    688    public static String getPackageCanonicalName(final String name) {
    689        return getPackageName(getCanonicalName(name));
    690    }
    691
    692    /**
    693     * Gets the package name of a {@link Class}.
    694     *
    695     * @param cls the class to get the package name for, may be {@code null}.
    696     * @return the package name or an empty string
    697     */
    698    public static String getPackageName(final Class<?> cls) {
    699        if (cls == null) {
    700            return StringUtils.EMPTY;
    701        }
    702        return getPackageName(cls.getName());
    703    }
    704
    705    /**
    706     * Gets the package name of an {@link Object}.
    707     *
    708     * @param object the class to get the package name for, may be null
    709     * @param valueIfNull the value to return if null
    710     * @return the package name of the object, or the null value
    711     */
    712    public static String getPackageName(final Object object, final String valueIfNull) {
    713        if (object == null) {
    714            return valueIfNull;
    715        }
    716        return getPackageName(object.getClass());
    717    }
    718
    719    /**
    720     * Gets the package name from a {@link String}.
    721     *
    722     * <p>
    723     * The string passed in is assumed to be a class name - it is not checked.
    724     * </p>
    725     * <p>
    726     * If the class is unpackaged, return an empty string.
    727     * </p>
    728     *
    729     * @param className the className to get the package name for, may be {@code null}
    730     * @return the package name or an empty string
    731     */
    732    public static String getPackageName(String className) {
    733        if (StringUtils.isEmpty(className)) {
    734            return StringUtils.EMPTY;
    735        }
    736
    737        // Strip array encoding
    738        while (className.charAt(0) == '[') {
    739            className = className.substring(1);
    740        }
    741        // Strip Object type encoding
    742        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    743            className = className.substring(1);
    744        }
    745
    746        final int i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    747        if (i == -1) {
    748            return StringUtils.EMPTY;
    749        }
    750        return className.substring(0, i);
    751    }
    752
    753    /**
    754     * Gets the primitive class for the given class name, for example "byte".
    755     *
    756     * @param className the primitive class for the given class name.
    757     * @return the primitive class.
    758     */
    759    static Class<?> getPrimitiveClass(final String className) {
    760        return namePrimitiveMap.get(className);
    761    }
    762
    763    /**
    764     * Returns the desired Method much like {@code Class.getMethod}, however it ensures that the returned Method is from a
    765     * public class or interface and not from an anonymous inner class. This means that the Method is invokable and doesn't
    766     * fall foul of Java bug <a href="https://bugs.java.com/bugdatabase/view_bug.do?bug_id=4071957">4071957</a>).
    767     *
    768     * <pre>
    769     *  {@code Set set = Collections.unmodifiableSet(...);
    770     *  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);
    771     *  Object result = method.invoke(set, new Object[]);}
    772     * </pre>
    773     *
    774     * @param cls the class to check, not null
    775     * @param methodName the name of the method
    776     * @param parameterTypes the list of parameters
    777     * @return the method
    778     * @throws NullPointerException if the class is null
    779     * @throws SecurityException if a security violation occurred
    780     * @throws NoSuchMethodException if the method is not found in the given class or if the method doesn't conform with the
    781     *         requirements
    782     */
    783    public static Method getPublicMethod(final Class<?> cls, final String methodName, final Class<?>... parameterTypes) throws NoSuchMethodException {
    784
    785        final Method declaredMethod = cls.getMethod(methodName, parameterTypes);
    786        if (isPublic(declaredMethod.getDeclaringClass())) {
    787            return declaredMethod;
    788        }
    789
    790        final List<Class<?>> candidateClasses = new ArrayList<>(getAllInterfaces(cls));
    791        candidateClasses.addAll(getAllSuperclasses(cls));
    792
    793        for (final Class<?> candidateClass : candidateClasses) {
    794            if (!isPublic(candidateClass)) {
    795                continue;
    796            }
    797            final Method candidateMethod;
    798            try {
    799                candidateMethod = candidateClass.getMethod(methodName, parameterTypes);
    800            } catch (final NoSuchMethodException ex) {
    801                continue;
    802            }
    803            if (Modifier.isPublic(candidateMethod.getDeclaringClass().getModifiers())) {
    804                return candidateMethod;
    805            }
    806        }
    807
    808        throw new NoSuchMethodException("Can't find a public method for " + methodName + " " + ArrayUtils.toString(parameterTypes));
    809    }
    810
    811    /**
    812     * Gets the canonical name minus the package name from a {@link Class}.
    813     *
    814     * @param cls the class for which to get the short canonical class name; may be null
    815     * @return the canonical name without the package name or an empty string
    816     * @since 2.4
    817     * @see Class#getCanonicalName()
    818     */
    819    public static String getShortCanonicalName(final Class<?> cls) {
    820        return cls == null ? StringUtils.EMPTY : getShortCanonicalName(cls.getCanonicalName());
    821    }
    822
    823    /**
    824     * Gets the canonical name minus the package name for an {@link Object}.
    825     *
    826     * @param object the class to get the short name for, may be null
    827     * @param valueIfNull the value to return if null
    828     * @return the canonical name of the object without the package name, or the null value
    829     * @since 2.4
    830     * @see Class#getCanonicalName()
    831     */
    832    public static String getShortCanonicalName(final Object object, final String valueIfNull) {
    833        return object == null ? valueIfNull : getShortCanonicalName(object.getClass().getCanonicalName());
    834    }
    835
    836    /**
    837     * Gets the canonical name minus the package name from a String.
    838     *
    839     * <p>
    840     * The string passed in is assumed to be a class name - it is not checked.
    841     * </p>
    842     *
    843     * <p>
    844     * Note that this method is mainly designed to handle the arrays and primitives properly. If the class is an inner class
    845     * then the result value will not contain the outer classes. This way the behavior of this method is different from
    846     * {@link #getShortClassName(String)}. The argument in that case is class name and not canonical name and the return
    847     * value retains the outer classes.
    848     * </p>
    849     *
    850     * <p>
    851     * Note that there is no way to reliably identify the part of the string representing the package hierarchy and the part
    852     * that is the outer class or classes in case of an inner class. Trying to find the class would require reflective call
    853     * and the class itself may not even be on the class path. Relying on the fact that class names start with capital
    854     * letter and packages with lower case is heuristic.
    855     * </p>
    856     *
    857     * <p>
    858     * It is recommended to use {@link #getShortClassName(String)} for cases when the class is an inner class and use this
    859     * method for cases it is designed for.
    860     * </p>
    861     *
    862     * <table>
    863     * <caption>Examples</caption>
    864     * <tr>
    865     * <td>return value</td>
    866     * <td>input</td>
    867     * </tr>
    868     * <tr>
    869     * <td>{@code ""}</td>
    870     * <td>{@code (String)null}</td>
    871     * </tr>
    872     * <tr>
    873     * <td>{@code "Map.Entry"}</td>
    874     * <td>{@code java.util.Map.Entry.class.getName()}</td>
    875     * </tr>
    876     * <tr>
    877     * <td>{@code "Entry"}</td>
    878     * <td>{@code java.util.Map.Entry.class.getCanonicalName()}</td>
    879     * </tr>
    880     * <tr>
    881     * <td>{@code "ClassUtils"}</td>
    882     * <td>{@code "org.apache.commons.lang3.ClassUtils"}</td>
    883     * </tr>
    884     * <tr>
    885     * <td>{@code "ClassUtils[]"}</td>
    886     * <td>{@code "[Lorg.apache.commons.lang3.ClassUtils;"}</td>
    887     * </tr>
    888     * <tr>
    889     * <td>{@code "ClassUtils[][]"}</td>
    890     * <td>{@code "[[Lorg.apache.commons.lang3.ClassUtils;"}</td>
    891     * </tr>
    892     * <tr>
    893     * <td>{@code "ClassUtils[]"}</td>
    894     * <td>{@code "org.apache.commons.lang3.ClassUtils[]"}</td>
    895     * </tr>
    896     * <tr>
    897     * <td>{@code "ClassUtils[][]"}</td>
    898     * <td>{@code "org.apache.commons.lang3.ClassUtils[][]"}</td>
    899     * </tr>
    900     * <tr>
    901     * <td>{@code "int[]"}</td>
    902     * <td>{@code "[I"}</td>
    903     * </tr>
    904     * <tr>
    905     * <td>{@code "int[]"}</td>
    906     * <td>{@code int[].class.getCanonicalName()}</td>
    907     * </tr>
    908     * <tr>
    909     * <td>{@code "int[]"}</td>
    910     * <td>{@code int[].class.getName()}</td>
    911     * </tr>
    912     * <tr>
    913     * <td>{@code "int[][]"}</td>
    914     * <td>{@code "[[I"}</td>
    915     * </tr>
    916     * <tr>
    917     * <td>{@code "int[]"}</td>
    918     * <td>{@code "int[]"}</td>
    919     * </tr>
    920     * <tr>
    921     * <td>{@code "int[][]"}</td>
    922     * <td>{@code "int[][]"}</td>
    923     * </tr>
    924     * </table>
    925     *
    926     * @param canonicalName the class name to get the short name for
    927     * @return the canonical name of the class without the package name or an empty string
    928     * @since 2.4
    929     */
    930    public static String getShortCanonicalName(final String canonicalName) {
    931        return getShortClassName(getCanonicalName(canonicalName));
    932    }
    933
    934    /**
    935     * Gets the class name minus the package name from a {@link Class}.
    936     *
    937     * <p>
    938     * This method simply gets the name using {@code Class.getName()} and then calls {@link #getShortClassName(String)}. See
    939     * relevant notes there.
    940     * </p>
    941     *
    942     * @param cls the class to get the short name for.
    943     * @return the class name without the package name or an empty string. If the class is an inner class then the returned
    944     *         value will contain the outer class or classes separated with {@code .} (dot) character.
    945     */
    946    public static String getShortClassName(final Class<?> cls) {
    947        if (cls == null) {
    948            return StringUtils.EMPTY;
    949        }
    950        return getShortClassName(cls.getName());
    951    }
    952
    953    /**
    954     * Gets the class name of the {@code object} without the package name or names.
    955     *
    956     * <p>
    957     * The method looks up the class of the object and then converts the name of the class invoking
    958     * {@link #getShortClassName(Class)} (see relevant notes there).
    959     * </p>
    960     *
    961     * @param object the class to get the short name for, may be {@code null}
    962     * @param valueIfNull the value to return if the object is {@code null}
    963     * @return the class name of the object without the package name, or {@code valueIfNull} if the argument {@code object}
    964     *         is {@code null}
    965     */
    966    public static String getShortClassName(final Object object, final String valueIfNull) {
    967        if (object == null) {
    968            return valueIfNull;
    969        }
    970        return getShortClassName(object.getClass());
    971    }
    972
    973    /**
    974     * Gets the class name minus the package name from a String.
    975     *
    976     * <p>
    977     * The string passed in is assumed to be a class name - it is not checked. The string has to be formatted the way as the
    978     * JDK method {@code Class.getName()} returns it, and not the usual way as we write it, for example in import
    979     * statements, or as it is formatted by {@code Class.getCanonicalName()}.
    980     * </p>
    981     *
    982     * <p>
    983     * The difference is is significant only in case of classes that are inner classes of some other classes. In this case
    984     * the separator between the outer and inner class (possibly on multiple hierarchy level) has to be {@code $} (dollar
    985     * sign) and not {@code .} (dot), as it is returned by {@code Class.getName()}
    986     * </p>
    987     *
    988     * <p>
    989     * Note that this method is called from the {@link #getShortClassName(Class)} method using the string returned by
    990     * {@code Class.getName()}.
    991     * </p>
    992     *
    993     * <p>
    994     * Note that this method differs from {@link #getSimpleName(Class)} in that this will return, for example
    995     * {@code "Map.Entry"} whilst the {@link Class} variant will simply return {@code "Entry"}. In this example
    996     * the argument {@code className} is the string {@code java.util.Map$Entry} (note the {@code $} sign.
    997     * </p>
    998     *
    999     * @param className the className to get the short name for. It has to be formatted as returned by
    1000     *        {@code Class.getName()} and not {@code Class.getCanonicalName()}
    1001     * @return the class name of the class without the package name or an empty string. If the class is an inner class then
    1002     *         value contains the outer class or classes and the separator is replaced to be {@code .} (dot) character.
    1003     */
    1004    public static String getShortClassName(String className) {
    1005        if (StringUtils.isEmpty(className)) {
    1006            return StringUtils.EMPTY;
    1007        }
    1008
    1009        final StringBuilder arrayPrefix = new StringBuilder();
    1010
    1011        // Handle array encoding
    1012        if (className.startsWith("[")) {
    1013            while (className.charAt(0) == '[') {
    1014                className = className.substring(1);
    1015                arrayPrefix.append("[]");
    1016            }
    1017            // Strip Object type encoding
    1018            if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    1019                className = className.substring(1, className.length() - 1);
    1020            }
    1021
    1022            if (reverseAbbreviationMap.containsKey(className)) {
    1023                className = reverseAbbreviationMap.get(className);
    1024            }
    1025        }
    1026
    1027        final int lastDotIdx = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    1028        final int innerIdx = className.indexOf(INNER_CLASS_SEPARATOR_CHAR, lastDotIdx == -1 ? 0 : lastDotIdx + 1);
    1029        String out = className.substring(lastDotIdx + 1);
    1030        if (innerIdx != -1) {
    1031            out = out.replace(INNER_CLASS_SEPARATOR_CHAR, PACKAGE_SEPARATOR_CHAR);
    1032        }
    1033        return out + arrayPrefix;
    1034    }
    1035
    1036    /**
    1037     * Null-safe version of {@code cls.getSimpleName()}
    1038     *
    1039     * @param cls the class for which to get the simple name; may be null
    1040     * @return the simple class name or the empty string in case the argument is {@code null}
    1041     * @since 3.0
    1042     * @see Class#getSimpleName()
    1043     */
    1044    public static String getSimpleName(final Class<?> cls) {
    1045        return getSimpleName(cls, StringUtils.EMPTY);
    1046    }
    1047
    1048    /**
    1049     * Null-safe version of {@code cls.getSimpleName()}
    1050     *
    1051     * @param cls the class for which to get the simple name; may be null
    1052     * @param valueIfNull the value to return if null
    1053     * @return the simple class name or {@code valueIfNull} if the argument {@code cls} is {@code null}
    1054     * @since 3.0
    1055     * @see Class#getSimpleName()
    1056     */
    1057    public static String getSimpleName(final Class<?> cls, final String valueIfNull) {
    1058        return cls == null ? valueIfNull : cls.getSimpleName();
    1059    }
    1060
    1061    /**
    1062     * Null-safe version of {@code object.getClass().getSimpleName()}
    1063     *
    1064     * <p>
    1065     * It is to note that this method is overloaded and in case the argument {@code object} is a {@link Class} object then
    1066     * the {@link #getSimpleName(Class)} will be invoked. If this is a significant possibility then the caller should check
    1067     * this case and call {@code
    1068     * getSimpleName(Class.class)} or just simply use the string literal {@code "Class"}, which is the result of the method
    1069     * in that case.
    1070     * </p>
    1071     *
    1072     * @param object the object for which to get the simple class name; may be null
    1073     * @return the simple class name or the empty string in case the argument is {@code null}
    1074     * @since 3.7
    1075     * @see Class#getSimpleName()
    1076     */
    1077    public static String getSimpleName(final Object object) {
    1078        return getSimpleName(object, StringUtils.EMPTY);
    1079    }
    1080
    1081    /**
    1082     * Null-safe version of {@code object.getClass().getSimpleName()}
    1083     *
    1084     * @param object the object for which to get the simple class name; may be null
    1085     * @param valueIfNull the value to return if {@code object} is {@code null}
    1086     * @return the simple class name or {@code valueIfNull} if the argument {@code object} is {@code null}
    1087     * @since 3.0
    1088     * @see Class#getSimpleName()
    1089     */
    1090    public static String getSimpleName(final Object object, final String valueIfNull) {
    1091        return object == null ? valueIfNull : object.getClass().getSimpleName();
    1092    }
    1093
    1094    /**
    1095     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order,
    1096     * excluding interfaces.
    1097     *
    1098     * @param type the type to get the class hierarchy from
    1099     * @return Iterable an Iterable over the class hierarchy of the given class
    1100     * @since 3.2
    1101     */
    1102    public static Iterable<Class<?>> hierarchy(final Class<?> type) {
    1103        return hierarchy(type, Interfaces.EXCLUDE);
    1104    }
    1105
    1106    /**
    1107     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order.
    1108     *
    1109     * @param type the type to get the class hierarchy from
    1110     * @param interfacesBehavior switch indicating whether to include or exclude interfaces
    1111     * @return Iterable an Iterable over the class hierarchy of the given class
    1112     * @since 3.2
    1113     */
    1114    public static Iterable<Class<?>> hierarchy(final Class<?> type, final Interfaces interfacesBehavior) {
    1115        final Iterable<Class<?>> classes = () -> {
    1116            final MutableObject<Class<?>> next = new MutableObject<>(type);
    1117            return new Iterator<Class<?>>() {
    1118
    1119                @Override
    1120                public boolean hasNext() {
    1121                    return next.getValue() != null;
    1122                }
    1123
    1124                @Override
    1125                public Class<?> next() {
    1126                    final Class<?> result = next.getValue();
    1127                    next.setValue(result.getSuperclass());
    1128                    return result;
    1129                }
    1130
    1131                @Override
    1132                public void remove() {
    1133                    throw new UnsupportedOperationException();
    1134                }
    1135
    1136            };
    1137        };
    1138        if (interfacesBehavior != Interfaces.INCLUDE) {
    1139            return classes;
    1140        }
    1141        return () -> {
    1142            final Set<Class<?>> seenInterfaces = new HashSet<>();
    1143            final Iterator<Class<?>> wrapped = classes.iterator();
    1144
    1145            return new Iterator<Class<?>>() {
    1146                Iterator<Class<?>> interfaces = Collections.emptyIterator();
    1147
    1148                @Override
    1149                public boolean hasNext() {
    1150                    return interfaces.hasNext() || wrapped.hasNext();
    1151                }
    1152
    1153                @Override
    1154                public Class<?> next() {
    1155                    if (interfaces.hasNext()) {
    1156                        final Class<?> nextInterface = interfaces.next();
    1157                        seenInterfaces.add(nextInterface);
    1158                        return nextInterface;
    1159                    }
    1160                    final Class<?> nextSuperclass = wrapped.next();
    1161                    final Set<Class<?>> currentInterfaces = new LinkedHashSet<>();
    1162                    walkInterfaces(currentInterfaces, nextSuperclass);
    1163                    interfaces = currentInterfaces.iterator();
    1164                    return nextSuperclass;
    1165                }
    1166
    1167                @Override
    1168                public void remove() {
    1169                    throw new UnsupportedOperationException();
    1170                }
    1171
    1172                private void walkInterfaces(final Set<Class<?>> addTo, final Class<?> c) {
    1173                    for (final Class<?> iface : c.getInterfaces()) {
    1174                        if (!seenInterfaces.contains(iface)) {
    1175                            addTo.add(iface);
    1176                        }
    1177                        walkInterfaces(addTo, iface);
    1178                    }
    1179                }
    1180
    1181            };
    1182        };
    1183    }
    1184
    1185    /**
    1186     * Checks if one {@link Class} can be assigned to a variable of another {@link Class}.
    1187     *
    1188     * <p>
    1189     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1190     * primitive classes and {@code null}s.
    1191     * </p>
    1192     *
    1193     * <p>
    1194     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
    1195     * for these cases.
    1196     * </p>
    1197     *
    1198     * <p>
    1199     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1200     * and the toClass is non-primitive.
    1201     * </p>
    1202     *
    1203     * <p>
    1204     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1205     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1206     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1207     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1208     * </p>
    1209     *
    1210     * <p>
    1211     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
    1212     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
    1213     * VMs running Java versions &gt; 1.5.
    1214     * </p>
    1215     *
    1216     * @param cls the Class to check, may be null
    1217     * @param toClass the Class to try to assign into, returns false if null
    1218     * @return {@code true} if assignment possible
    1219     */
    1220    public static boolean isAssignable(final Class<?> cls, final Class<?> toClass) {
    1221        return isAssignable(cls, toClass, true);
    1222    }
    1223
    1224    /**
    1225     * Checks if one {@link Class} can be assigned to a variable of another {@link Class}.
    1226     *
    1227     * <p>
    1228     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1229     * primitive classes and {@code null}s.
    1230     * </p>
    1231     *
    1232     * <p>
    1233     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
    1234     * for these cases.
    1235     * </p>
    1236     *
    1237     * <p>
    1238     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1239     * and the toClass is non-primitive.
    1240     * </p>
    1241     *
    1242     * <p>
    1243     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1244     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1245     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1246     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1247     * </p>
    1248     *
    1249     * @param cls the Class to check, may be null
    1250     * @param toClass the Class to try to assign into, returns false if null
    1251     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
    1252     * @return {@code true} if assignment possible
    1253     */
    1254    public static boolean isAssignable(Class<?> cls, final Class<?> toClass, final boolean autoboxing) {
    1255        if (toClass == null) {
    1256            return false;
    1257        }
    1258        // have to check for null, as isAssignableFrom doesn't
    1259        if (cls == null) {
    1260            return !toClass.isPrimitive();
    1261        }
    1262        // autoboxing:
    1263        if (autoboxing) {
    1264            if (cls.isPrimitive() && !toClass.isPrimitive()) {
    1265                cls = primitiveToWrapper(cls);
    1266                if (cls == null) {
    1267                    return false;
    1268                }
    1269            }
    1270            if (toClass.isPrimitive() && !cls.isPrimitive()) {
    1271                cls = wrapperToPrimitive(cls);
    1272                if (cls == null) {
    1273                    return false;
    1274                }
    1275            }
    1276        }
    1277        if (cls.equals(toClass)) {
    1278            return true;
    1279        }
    1280        if (cls.isPrimitive()) {
    1281            if (!toClass.isPrimitive()) {
    1282                return false;
    1283            }
    1284            if (Integer.TYPE.equals(cls)) {
    1285                return Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1286            }
    1287            if (Long.TYPE.equals(cls)) {
    1288                return Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1289            }
    1290            if (Boolean.TYPE.equals(cls)) {
    1291                return false;
    1292            }
    1293            if (Double.TYPE.equals(cls)) {
    1294                return false;
    1295            }
    1296            if (Float.TYPE.equals(cls)) {
    1297                return Double.TYPE.equals(toClass);
    1298            }
    1299            if (Character.TYPE.equals(cls)  || Short.TYPE.equals(cls)) {
    1300                return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1301            }
    1302            if (Byte.TYPE.equals(cls)) {
    1303                return Short.TYPE.equals(toClass) || Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
    1304                    || Double.TYPE.equals(toClass);
    1305            }
    1306            // should never get here
    1307            return false;
    1308        }
    1309        return toClass.isAssignableFrom(cls);
    1310    }
    1311
    1312    /**
    1313     * Checks if an array of Classes can be assigned to another array of Classes.
    1314     *
    1315     * <p>
    1316     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
    1317     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
    1318     * types (the second parameter).
    1319     * </p>
    1320     *
    1321     * <p>
    1322     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1323     * primitive classes and {@code null}s.
    1324     * </p>
    1325     *
    1326     * <p>
    1327     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
    1328     * returns the correct result for these cases.
    1329     * </p>
    1330     *
    1331     * <p>
    1332     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1333     * and the toClass is non-primitive.
    1334     * </p>
    1335     *
    1336     * <p>
    1337     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1338     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1339     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1340     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1341     * </p>
    1342     *
    1343     * <p>
    1344     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
    1345     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
    1346     * VMs running Java versions &gt; 1.5.
    1347     * </p>
    1348     *
    1349     * @param classArray the array of Classes to check, may be {@code null}
    1350     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
    1351     * @return {@code true} if assignment possible
    1352     */
    1353    public static boolean isAssignable(final Class<?>[] classArray, final Class<?>... toClassArray) {
    1354        return isAssignable(classArray, toClassArray, true);
    1355    }
    1356
    1357    /**
    1358     * Checks if an array of Classes can be assigned to another array of Classes.
    1359     *
    1360     * <p>
    1361     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
    1362     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
    1363     * types (the second parameter).
    1364     * </p>
    1365     *
    1366     * <p>
    1367     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1368     * primitive classes and {@code null}s.
    1369     * </p>
    1370     *
    1371     * <p>
    1372     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
    1373     * returns the correct result for these cases.
    1374     * </p>
    1375     *
    1376     * <p>
    1377     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1378     * and the toClass is non-primitive.
    1379     * </p>
    1380     *
    1381     * <p>
    1382     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1383     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1384     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1385     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1386     * </p>
    1387     *
    1388     * @param classArray the array of Classes to check, may be {@code null}
    1389     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
    1390     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
    1391     * @return {@code true} if assignment possible
    1392     */
    1393    public static boolean isAssignable(Class<?>[] classArray, Class<?>[] toClassArray, final boolean autoboxing) {
    1394        if (!ArrayUtils.isSameLength(classArray, toClassArray)) {
    1395            return false;
    1396        }
    1397        classArray = ArrayUtils.nullToEmpty(classArray);
    1398        toClassArray = ArrayUtils.nullToEmpty(toClassArray);
    1399        for (int i = 0; i < classArray.length; i++) {
    1400            if (!isAssignable(classArray[i], toClassArray[i], autoboxing)) {
    1401                return false;
    1402            }
    1403        }
    1404        return true;
    1405    }
    1406
    1407    /**
    1408     * Is the specified class an inner class or static nested class.
    1409     *
    1410     * @param cls the class to check, may be null
    1411     * @return {@code true} if the class is an inner or static nested class, false if not or {@code null}
    1412     */
    1413    public static boolean isInnerClass(final Class<?> cls) {
    1414        return cls != null && cls.getEnclosingClass() != null;
    1415    }
    1416
    1417    /**
    1418     * Returns whether the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
    1419     * {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1420     *
    1421     * @param type The class to query or null.
    1422     * @return true if the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
    1423     *         {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1424     * @since 3.1
    1425     */
    1426    public static boolean isPrimitiveOrWrapper(final Class<?> type) {
    1427        if (type == null) {
    1428            return false;
    1429        }
    1430        return type.isPrimitive() || isPrimitiveWrapper(type);
    1431    }
    1432    /**
    1433     * Returns whether the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    1434     * {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1435     *
    1436     * @param type The class to query or null.
    1437     * @return true if the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    1438     *         {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1439     * @since 3.1
    1440     */
    1441    public static boolean isPrimitiveWrapper(final Class<?> type) {
    1442        return wrapperPrimitiveMap.containsKey(type);
    1443    }
    1444
    1445    /**
    1446     * Tests whether a {@link Class} is public.
    1447     * @param cls Class to test.
    1448     * @return {@code true} if {@code cls} is public.
    1449     * @since 3.13.0
    1450     */
    1451    public static boolean isPublic(final Class<?> cls) {
    1452        return Modifier.isPublic(cls.getModifiers());
    1453    }
    1454
    1455    /**
    1456     * Converts the specified array of primitive Class objects to an array of its corresponding wrapper Class objects.
    1457     *
    1458     * @param classes the class array to convert, may be null or empty
    1459     * @return an array which contains for each given class, the wrapper class or the original class if class is not a
    1460     *         primitive. {@code null} if null input. Empty array if an empty array passed in.
    1461     * @since 2.1
    1462     */
    1463    public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {
    1464        if (classes == null) {
    1465            return null;
    1466        }
    1467
    1468        if (classes.length == 0) {
    1469            return classes;
    1470        }
    1471
    1472        final Class<?>[] convertedClasses = new Class[classes.length];
    1473        Arrays.setAll(convertedClasses, i -> primitiveToWrapper(classes[i]));
    1474        return convertedClasses;
    1475    }
    1476
    1477    /**
    1478     * Converts the specified primitive Class object to its corresponding wrapper Class object.
    1479     *
    1480     * <p>
    1481     * NOTE: From v2.2, this method handles {@code Void.TYPE}, returning {@code Void.TYPE}.
    1482     * </p>
    1483     *
    1484     * @param cls the class to convert, may be null
    1485     * @return the wrapper class for {@code cls} or {@code cls} if {@code cls} is not a primitive. {@code null} if null
    1486     *         input.
    1487     * @since 2.1
    1488     */
    1489    public static Class<?> primitiveToWrapper(final Class<?> cls) {
    1490        Class<?> convertedClass = cls;
    1491        if (cls != null && cls.isPrimitive()) {
    1492            convertedClass = primitiveWrapperMap.get(cls);
    1493        }
    1494        return convertedClass;
    1495    }
    1496
    1497    /**
    1498     * Converts a class name to a JLS style class name.
    1499     *
    1500     * @param className the class name
    1501     * @return the converted name
    1502     * @throws NullPointerException if the className is null
    1503     */
    1504    private static String toCanonicalName(final String className) {
    1505        String canonicalName = StringUtils.deleteWhitespace(className);
    1506        Objects.requireNonNull(canonicalName, "className");
    1507        if (canonicalName.endsWith("[]")) {
    1508            final StringBuilder classNameBuffer = new StringBuilder();
    1509            while (canonicalName.endsWith("[]")) {
    1510                canonicalName = canonicalName.substring(0, canonicalName.length() - 2);
    1511                classNameBuffer.append("[");
    1512            }
    1513            final String abbreviation = abbreviationMap.get(canonicalName);
    1514            if (abbreviation != null) {
    1515                classNameBuffer.append(abbreviation);
    1516            } else {
    1517                classNameBuffer.append("L").append(canonicalName).append(";");
    1518            }
    1519            canonicalName = classNameBuffer.toString();
    1520        }
    1521        return canonicalName;
    1522    }
    1523
    1524    /**
    1525     * Converts an array of {@link Object} in to an array of {@link Class} objects. If any of these objects is null, a null
    1526     * element will be inserted into the array.
    1527     *
    1528     * <p>
    1529     * This method returns {@code null} for a {@code null} input array.
    1530     * </p>
    1531     *
    1532     * @param array an {@link Object} array
    1533     * @return a {@link Class} array, {@code null} if null array input
    1534     * @since 2.4
    1535     */
    1536    public static Class<?>[] toClass(final Object... array) {
    1537        if (array == null) {
    1538            return null;
    1539        }
    1540        if (array.length == 0) {
    1541            return ArrayUtils.EMPTY_CLASS_ARRAY;
    1542        }
    1543        final Class<?>[] classes = new Class[array.length];
    1544        Arrays.setAll(classes, i -> array[i] == null ? null : array[i].getClass());
    1545        return classes;
    1546    }
    1547
    1548    /**
    1549     * Decides if the part that was just copied to its destination location in the work array can be kept as it was copied
    1550     * or must be abbreviated. It must be kept when the part is the last one, which is the simple name of the class. In this
    1551     * case the {@code source} index, from where the characters are copied points one position after the last character,
    1552     * a.k.a. {@code source ==
    1553     * originalLength}
    1554     *
    1555     * <p>
    1556     * If the part is not the last one then it can be kept unabridged if the number of the characters copied so far plus the
    1557     * character that are to be copied is less than or equal to the desired length.
    1558     * </p>
    1559     *
    1560     * @param runAheadTarget the target index (where the characters were copied to) pointing after the last character copied
    1561     *        when the current part was copied
    1562     * @param source the source index (where the characters were copied from) pointing after the last character copied when
    1563     *        the current part was copied
    1564     * @param originalLength the original length of the class full name, which is abbreviated
    1565     * @param desiredLength the desired length of the abbreviated class name
    1566     * @return {@code true} if it can be kept in its original length {@code false} if the current part has to be abbreviated
    1567     *         and
    1568     */
    1569    private static boolean useFull(final int runAheadTarget, final int source, final int originalLength, final int desiredLength) {
    1570        return source >= originalLength || runAheadTarget + originalLength - source <= desiredLength;
    1571    }
    1572
    1573    /**
    1574     * Converts the specified array of wrapper Class objects to an array of its corresponding primitive Class objects.
    1575     *
    1576     * <p>
    1577     * This method invokes {@code wrapperToPrimitive()} for each element of the passed in array.
    1578     * </p>
    1579     *
    1580     * @param classes the class array to convert, may be null or empty
    1581     * @return an array which contains for each given class, the primitive class or <b>null</b> if the original class is not
    1582     *         a wrapper class. {@code null} if null input. Empty array if an empty array passed in.
    1583     * @see #wrapperToPrimitive(Class)
    1584     * @since 2.4
    1585     */
    1586    public static Class<?>[] wrappersToPrimitives(final Class<?>... classes) {
    1587        if (classes == null) {
    1588            return null;
    1589        }
    1590
    1591        if (classes.length == 0) {
    1592            return classes;
    1593        }
    1594
    1595        final Class<?>[] convertedClasses = new Class[classes.length];
    1596        Arrays.setAll(convertedClasses, i -> wrapperToPrimitive(classes[i]));
    1597        return convertedClasses;
    1598    }
    1599
    1600    /**
    1601     * Converts the specified wrapper class to its corresponding primitive class.
    1602     *
    1603     * <p>
    1604     * This method is the counter part of {@code primitiveToWrapper()}. If the passed in class is a wrapper class for a
    1605     * primitive type, this primitive type will be returned (e.g. {@code Integer.TYPE} for {@code Integer.class}). For other
    1606     * classes, or if the parameter is <b>null</b>, the return value is <b>null</b>.
    1607     * </p>
    1608     *
    1609     * @param cls the class to convert, may be <b>null</b>
    1610     * @return the corresponding primitive type if {@code cls} is a wrapper class, <b>null</b> otherwise
    1611     * @see #primitiveToWrapper(Class)
    1612     * @since 2.4
    1613     */
    1614    public static Class<?> wrapperToPrimitive(final Class<?> cls) {
    1615        return wrapperPrimitiveMap.get(cls);
    1616    }
    1617
    1618    /**
    1619     * ClassUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
    1620     * {@code ClassUtils.getShortClassName(cls)}.
    1621     *
    1622     * <p>
    1623     * This constructor is public to permit tools that require a JavaBean instance to operate.
    1624     * </p>
    1625     *
    1626     * @deprecated TODO Make private in 4.0.
    1627     */
    1628    @Deprecated
    1629    public ClassUtils() {
    1630        // empty
    1631    }
    1632
    1633}