    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.Collections;
    023import java.util.HashMap;
    024import java.util.HashSet;
    025import java.util.Iterator;
    026import java.util.LinkedHashSet;
    027import java.util.List;
    028import java.util.Map;
    029import java.util.Set;
    030
    031import org.apache.commons.lang3.mutable.MutableObject;
    032
    033/**
    034 * <p>Operates on classes without using reflection.</p>
    035 *
    036 * <p>This class handles invalid {@code null} inputs as best it can.
    037 * Each method documents its behavior in more detail.</p>
    038 *
    039 * <p>The notion of a {@code canonical name} includes the human
    040 * readable name for the type, for example {@code int[]}. The
    041 * non-canonical method variants work with the JVM names, such as
    042 * {@code [I}. </p>
    043 *
    044 * @since 2.0
    045 */
    046public class ClassUtils {
    047
    048    /**
    049     * Inclusivity literals for {@link #hierarchy(Class, Interfaces)}.
    050     * @since 3.2
    051     */
    052    public enum Interfaces {
    053
    054        /** Includes interfaces. */
    055        INCLUDE,
    056
    057        /** Excludes interfaces. */
    058        EXCLUDE
    059    }
    060
    061    /**
    062     * The package separator character: {@code '&#x2e;' == {@value}}.
    063     */
    064    public static final char PACKAGE_SEPARATOR_CHAR = '.';
    065
    066    /**
    067     * The package separator String: {@code "&#x2e;"}.
    068     */
    069    public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);
    070
    071    /**
    072     * The inner class separator character: {@code '$' == {@value}}.
    073     */
    074    public static final char INNER_CLASS_SEPARATOR_CHAR = '$';
    075
    076    /**
    077     * The inner class separator String: {@code "$"}.
    078     */
    079    public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);
    080
    081    /**
    082     * Maps names of primitives to their corresponding primitive {@code Class}es.
    083     */
    084    private static final Map<String, Class<?>> namePrimitiveMap = new HashMap<>();
    085    static {
    086         namePrimitiveMap.put("boolean", Boolean.TYPE);
    087         namePrimitiveMap.put("byte", Byte.TYPE);
    088         namePrimitiveMap.put("char", Character.TYPE);
    089         namePrimitiveMap.put("short", Short.TYPE);
    090         namePrimitiveMap.put("int", Integer.TYPE);
    091         namePrimitiveMap.put("long", Long.TYPE);
    092         namePrimitiveMap.put("double", Double.TYPE);
    093         namePrimitiveMap.put("float", Float.TYPE);
    094         namePrimitiveMap.put("void", Void.TYPE);
    095    }
    096
    097    /**
    098     * Maps primitive {@code Class}es to their corresponding wrapper {@code Class}.
    099     */
    100    private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<>();
    101    static {
    102         primitiveWrapperMap.put(Boolean.TYPE, Boolean.class);
    103         primitiveWrapperMap.put(Byte.TYPE, Byte.class);
    104         primitiveWrapperMap.put(Character.TYPE, Character.class);
    105         primitiveWrapperMap.put(Short.TYPE, Short.class);
    106         primitiveWrapperMap.put(Integer.TYPE, Integer.class);
    107         primitiveWrapperMap.put(Long.TYPE, Long.class);
    108         primitiveWrapperMap.put(Double.TYPE, Double.class);
    109         primitiveWrapperMap.put(Float.TYPE, Float.class);
    110         primitiveWrapperMap.put(Void.TYPE, Void.TYPE);
    111    }
    112
    113    /**
    114     * Maps wrapper {@code Class}es to their corresponding primitive types.
    115     */
    116    private static final Map<Class<?>, Class<?>> wrapperPrimitiveMap = new HashMap<>();
    117    static {
    118        for (final Map.Entry<Class<?>, Class<?>> entry : primitiveWrapperMap.entrySet()) {
    119            final Class<?> primitiveClass = entry.getKey();
    120            final Class<?> wrapperClass = entry.getValue();
    121            if (!primitiveClass.equals(wrapperClass)) {
    122                wrapperPrimitiveMap.put(wrapperClass, primitiveClass);
    123            }
    124        }
    125    }
    126
    127    /**
    128     * Maps a primitive class name to its corresponding abbreviation used in array class names.
    129     */
    130    private static final Map<String, String> abbreviationMap;
    131
    132    /**
    133     * Maps an abbreviation used in array class names to corresponding primitive class name.
    134     */
    135    private static final Map<String, String> reverseAbbreviationMap;
    136    // Feed abbreviation maps
    137    static {
    138        final Map<String, String> m = new HashMap<>();
    139        m.put("int", "I");
    140        m.put("boolean", "Z");
    141        m.put("float", "F");
    142        m.put("long", "J");
    143        m.put("short", "S");
    144        m.put("byte", "B");
    145        m.put("double", "D");
    146        m.put("char", "C");
    147        final Map<String, String> r = new HashMap<>();
    148        for (final Map.Entry<String, String> e : m.entrySet()) {
    149            r.put(e.getValue(), e.getKey());
    150        }
    151        abbreviationMap = Collections.unmodifiableMap(m);
    152        reverseAbbreviationMap = Collections.unmodifiableMap(r);
    153    }
    154
    155    /**
    156     * <p>ClassUtils instances should NOT be constructed in standard programming.
    157     * Instead, the class should be used as
    158     * {@code ClassUtils.getShortClassName(cls)}.</p>
    159     *
    160     * <p>This constructor is public to permit tools that require a JavaBean
    161     * instance to operate.</p>
    162     */
    163    public ClassUtils() {
    164    }
    165
    166    // Short class name
    167    // ----------------------------------------------------------------------
    168    /**
    169     * <p>Gets the class name of the {@code object} without the package name or names.</p>
    170     *
    171     * <p>The method looks up the class of the object and then converts the name of the class invoking
    172     * {@link #getShortClassName(Class)} (see relevant notes there).</p>
    173     *
    174     * @param object  the class to get the short name for, may be {@code null}
    175     * @param valueIfNull  the value to return if the object is {@code null}
    176     * @return the class name of the object without the package name, or {@code valueIfNull}
    177     *         if the argument {@code object} is {@code null}
    178     */
    179    public static String getShortClassName(final Object object, final String valueIfNull) {
    180        if (object == null) {
    181            return valueIfNull;
    182        }
    183        return getShortClassName(object.getClass());
    184    }
    185
    186    /**
    187     * <p>Gets the class name minus the package name from a {@code Class}.</p>
    188     *
    189     * <p>This method simply gets the name using {@code Class.getName()} and then calls
    190     * {@link #getShortClassName(Class)}. See relevant notes there.</p>
    191     *
    192     * @param cls  the class to get the short name for.
    193     * @return the class name without the package name or an empty string. If the class
    194     *         is an inner class then the returned value will contain the outer class
    195     *         or classes separated with {@code .} (dot) character.
    196     */
    197    public static String getShortClassName(final Class<?> cls) {
    198        if (cls == null) {
    199            return StringUtils.EMPTY;
    200        }
    201        return getShortClassName(cls.getName());
    202    }
    203
    204    /**
    205     * <p>Gets the class name minus the package name from a String.</p>
    206     *
    207     * <p>The string passed in is assumed to be a class name - it is not checked. The string has to be formatted the way
    208     * as the JDK method {@code Class.getName()} returns it, and not the usual way as we write it, for example in import
    209     * statements, or as it is formatted by {@code Class.getCanonicalName()}.</p>
    210     *
    211     * <p>The difference is is significant only in case of classes that are inner classes of some other
    212     * classes. In this case the separator between the outer and inner class (possibly on multiple hierarchy level) has
    213     * to be {@code $} (dollar sign) and not {@code .} (dot), as it is returned by {@code Class.getName()}</p>
    214     *
    215     * <p>Note that this method is called from the {@link #getShortClassName(Class)} method using the string
    216     * returned by {@code Class.getName()}.</p>
    217     *
    218     * <p>Note that this method differs from {@link #getSimpleName(Class)} in that this will
    219     * return, for example {@code "Map.Entry"} whilst the {@code java.lang.Class} variant will simply
    220     * return {@code "Entry"}. In this example the argument {@code className} is the string
    221     * {@code java.util.Map$Entry} (note the {@code $} sign.</p>
    222     *
    223     * @param className  the className to get the short name for. It has to be formatted as returned by
    224     *                   {@code Class.getName()} and not {@code Class.getCanonicalName()}
    225     * @return the class name of the class without the package name or an empty string. If the class is
    226     *         an inner class then value contains the outer class or classes and the separator is replaced
    227     *         to be {@code .} (dot) character.
    228     */
    229    public static String getShortClassName(String className) {
    230        if (StringUtils.isEmpty(className)) {
    231            return StringUtils.EMPTY;
    232        }
    233
    234        final StringBuilder arrayPrefix = new StringBuilder();
    235
    236        // Handle array encoding
    237        if (className.startsWith("[")) {
    238            while (className.charAt(0) == '[') {
    239                className = className.substring(1);
    240                arrayPrefix.append("[]");
    241            }
    242            // Strip Object type encoding
    243            if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    244                className = className.substring(1, className.length() - 1);
    245            }
    246
    247            if (reverseAbbreviationMap.containsKey(className)) {
    248                className = reverseAbbreviationMap.get(className);
    249            }
    250        }
    251
    252        final int lastDotIdx = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    253        final int innerIdx = className.indexOf(
    254                INNER_CLASS_SEPARATOR_CHAR, lastDotIdx == -1 ? 0 : lastDotIdx + 1);
    255        String out = className.substring(lastDotIdx + 1);
    256        if (innerIdx != -1) {
    257            out = out.replace(INNER_CLASS_SEPARATOR_CHAR, PACKAGE_SEPARATOR_CHAR);
    258        }
    259        return out + arrayPrefix;
    260    }
    261
    262    /**
    263     * <p>Null-safe version of {@code cls.getSimpleName()}</p>
    264     *
    265     * @param cls the class for which to get the simple name; may be null
    266     * @return the simple class name or the empty string in case the argument is {@code null}
    267     * @since 3.0
    268     * @see Class#getSimpleName()
    269     */
    270    public static String getSimpleName(final Class<?> cls) {
    271        return getSimpleName(cls, StringUtils.EMPTY);
    272    }
    273
    274    /**
    275     * <p>Null-safe version of {@code cls.getSimpleName()}</p>
    276     *
    277     * @param cls the class for which to get the simple name; may be null
    278     * @param valueIfNull  the value to return if null
    279     * @return the simple class name or {@code valueIfNull} if the
    280     *         argument {@code cls} is {@code null}
    281     * @since 3.0
    282     * @see Class#getSimpleName()
    283     */
    284    public static String getSimpleName(final Class<?> cls, final String valueIfNull) {
    285        return cls == null ? valueIfNull : cls.getSimpleName();
    286    }
    287
    288    /**
    289     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>
    290     *
    291     * <p>It is to note that this method is overloaded and in case the argument {@code object} is a
    292     * {@code Class} object then the {@link #getSimpleName(Class)} will be invoked. If this is
    293     * a significant possibility then the caller should check this case and call {@code
    294     * getSimpleName(Class.class)} or just simply use the string literal {@code "Class"}, which
    295     * is the result of the method in that case.</p>
    296     *
    297     * @param object the object for which to get the simple class name; may be null
    298     * @return the simple class name or the empty string in case the argument is {@code null}
    299     * @since 3.7
    300     * @see Class#getSimpleName()
    301     */
    302    public static String getSimpleName(final Object object) {
    303        return getSimpleName(object, StringUtils.EMPTY);
    304    }
    305
    306    /**
    307     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>
    308     *
    309     * @param object the object for which to get the simple class name; may be null
    310     * @param valueIfNull the value to return if {@code object} is {@code null}
    311     * @return the simple class name or {@code valueIfNull} if the
    312     *         argument {@code object} is {@code null}
    313     * @since 3.0
    314     * @see Class#getSimpleName()
    315     */
    316    public static String getSimpleName(final Object object, final String valueIfNull) {
    317        return object == null ? valueIfNull : object.getClass().getSimpleName();
    318    }
    319
    320    /**
    321     * <p>Null-safe version of {@code cls.getName()}</p>
    322     *
    323     * @param cls the class for which to get the class name; may be null
    324     * @return the class name or the empty string in case the argument is {@code null}
    325     * @since 3.7
    326     * @see Class#getSimpleName()
    327     */
    328    public static String getName(final Class<?> cls) {
    329        return getName(cls, StringUtils.EMPTY);
    330    }
    331
    332    /**
    333     * <p>Null-safe version of {@code cls.getName()}</p>
    334     *
    335     * @param cls the class for which to get the class name; may be null
    336     * @param valueIfNull the return value if the argument {@code cls} is {@code null}
    337     * @return the class name or {@code valueIfNull}
    338     * @since 3.7
    339     * @see Class#getName()
    340     */
    341    public static String getName(final Class<?> cls, final String valueIfNull) {
    342        return cls == null ? valueIfNull : cls.getName();
    343    }
    344
    345    /**
    346     * <p>Null-safe version of {@code object.getClass().getName()}</p>
    347     *
    348     * @param object the object for which to get the class name; may be null
    349     * @return the class name or the empty String
    350     * @since 3.7
    351     * @see Class#getSimpleName()
    352     */
    353    public static String getName(final Object object) {
    354        return getName(object, StringUtils.EMPTY);
    355    }
    356
    357    /**
    358     * <p>Null-safe version of {@code object.getClass().getSimpleName()}</p>
    359     *
    360     * @param object the object for which to get the class name; may be null
    361     * @param valueIfNull the value to return if {@code object} is {@code null}
    362     * @return the class name or {@code valueIfNull}
    363     * @since 3.0
    364     * @see Class#getName()
    365     */
    366    public static String getName(final Object object, final String valueIfNull) {
    367        return object == null ? valueIfNull : object.getClass().getName();
    368    }
    369
    370    // Package name
    371    // ----------------------------------------------------------------------
    372    /**
    373     * <p>Gets the package name of an {@code Object}.</p>
    374     *
    375     * @param object  the class to get the package name for, may be null
    376     * @param valueIfNull  the value to return if null
    377     * @return the package name of the object, or the null value
    378     */
    379    public static String getPackageName(final Object object, final String valueIfNull) {
    380        if (object == null) {
    381            return valueIfNull;
    382        }
    383        return getPackageName(object.getClass());
    384    }
    385
    386    /**
    387     * <p>Gets the package name of a {@code Class}.</p>
    388     *
    389     * @param cls  the class to get the package name for, may be {@code null}.
    390     * @return the package name or an empty string
    391     */
    392    public static String getPackageName(final Class<?> cls) {
    393        if (cls == null) {
    394            return StringUtils.EMPTY;
    395        }
    396        return getPackageName(cls.getName());
    397    }
    398
    399    /**
    400     * <p>Gets the package name from a {@code String}.</p>
    401     *
    402     * <p>The string passed in is assumed to be a class name - it is not checked.</p>
    403     * <p>If the class is unpackaged, return an empty string.</p>
    404     *
    405     * @param className  the className to get the package name for, may be {@code null}
    406     * @return the package name or an empty string
    407     */
    408    public static String getPackageName(String className) {
    409        if (StringUtils.isEmpty(className)) {
    410            return StringUtils.EMPTY;
    411        }
    412
    413        // Strip array encoding
    414        while (className.charAt(0) == '[') {
    415            className = className.substring(1);
    416        }
    417        // Strip Object type encoding
    418        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    419            className = className.substring(1);
    420        }
    421
    422        final int i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    423        if (i == -1) {
    424            return StringUtils.EMPTY;
    425        }
    426        return className.substring(0, i);
    427    }
    428
    429    // Abbreviated name
    430    // ----------------------------------------------------------------------
    431    /**
    432     * <p>Gets the abbreviated name of a {@code Class}.</p>
    433     *
    434     * @param cls  the class to get the abbreviated name for, may be {@code null}
    435     * @param lengthHint  the desired length of the abbreviated name
    436     * @return the abbreviated name or an empty string
    437     * @throws IllegalArgumentException if len &lt;= 0
    438     * @see #getAbbreviatedName(String, int)
    439     * @since 3.4
    440     */
    441    public static String getAbbreviatedName(final Class<?> cls, final int lengthHint) {
    442      if (cls == null) {
    443        return StringUtils.EMPTY;
    444      }
    445      return getAbbreviatedName(cls.getName(), lengthHint);
    446    }
    447
    448    /**
    449     * <p>Gets the abbreviated class name from a {@code String}.</p>
    450     *
    451     * <p>The string passed in is assumed to be a class name - it is not checked.</p>
    452     *
    453     * <p>The abbreviation algorithm will shorten the class name, usually without
    454     * significant loss of meaning.</p>
    455     *
    456     * <p>The abbreviated class name will always include the complete package hierarchy.
    457     * If enough space is available, rightmost sub-packages will be displayed in full
    458     * length. The abbreviated package names will be shortened to a single character.</p>
    459     * <p>Only package names are shortened, the class simple name remains untouched. (See examples.)</p>
    460     * <p>The result will be longer than the desired length only if all the package names
    461     * shortened to a single character plus the class simple name with the separating dots
    462     * together are longer than the desired length. In other words, when the class name
    463     * cannot be shortened to the desired length.</p>
    464     * <p>If the class name can be shortened then
    465     * the final length will be at most {@code lengthHint} characters.</p>
    466     * <p>If the {@code lengthHint} is zero or negative then the method
    467     * throws exception. If you want to achieve the shortest possible version then
    468     * use {@code 1} as a {@code lengthHint}.</p>
    469     *
    470     * <table>
    471     * <caption>Examples</caption>
    472     * <tr><td>className</td><td>len</td><td>return</td></tr>
    473     * <tr><td>              null</td><td> 1</td><td>""</td></tr>
    474     * <tr><td>"java.lang.String"</td><td> 5</td><td>"j.l.String"</td></tr>
    475     * <tr><td>"java.lang.String"</td><td>15</td><td>"j.lang.String"</td></tr>
    476     * <tr><td>"java.lang.String"</td><td>30</td><td>"java.lang.String"</td></tr>
    477     * <tr><td>"org.apache.commons.lang3.ClassUtils"</td><td>18</td><td>"o.a.c.l.ClassUtils"</td></tr>
    478     * </table>
    479     *
    480     * @param className the className to get the abbreviated name for, may be {@code null}
    481     * @param lengthHint       the desired length of the abbreviated name
    482     * @return the abbreviated name or an empty string if the specified
    483     * class name is {@code null} or empty string. The abbreviated name may be
    484     * longer than the desired length if it cannot be abbreviated to the desired length.
    485     * @throws IllegalArgumentException if {@code len <= 0}
    486     * @since 3.4
    487     */
    488    public static String getAbbreviatedName(final String className, final int lengthHint) {
    489        if (lengthHint <= 0) {
    490            throw new IllegalArgumentException("len must be > 0");
    491        }
    492        if (className == null) {
    493            return StringUtils.EMPTY;
    494        }
    495        if (className.length() <= lengthHint) {
    496            return className;
    497        }
    498        final char[] abbreviated = className.toCharArray();
    499        int target = 0;
    500        int source = 0;
    501        while (source < abbreviated.length) {
    502            // copy the next part
    503            int runAheadTarget = target;
    504            while (source < abbreviated.length && abbreviated[source] != '.') {
    505                abbreviated[runAheadTarget++] = abbreviated[source++];
    506            }
    507
    508            ++target;
    509            if (useFull(runAheadTarget, source, abbreviated.length, lengthHint)
    510                  || target > runAheadTarget) {
    511                target = runAheadTarget;
    512            }
    513
    514            // copy the '.' unless it was the last part
    515            if (source < abbreviated.length) {
    516                abbreviated[target++] = abbreviated[source++];
    517            }
    518        }
    519        return new String(abbreviated, 0, target);
    520    }
    521
    522    /**
    523     * <p>Decides if the part that was just copied to its destination
    524     * location in the work array can be kept as it was copied or must be
    525     * abbreviated. It must be kept when the part is the last one, which
    526     * is the simple name of the class. In this case the {@code source}
    527     * index, from where the characters are copied points one position
    528     * after the last character, a.k.a. {@code source ==
    529     * originalLength}</p>
    530     *
    531     * <p>If the part is not the last one then it can be kept
    532     * unabridged if the number of the characters copied so far plus
    533     * the character that are to be copied is less than or equal to the
    534     * desired length.</p>
    535     *
    536     * @param runAheadTarget the target index (where the characters were
    537     *                       copied to) pointing after the last character
    538     *                       copied when the current part was copied
    539     * @param source         the source index (where the characters were
    540     *                       copied from) pointing after the last
    541     *                       character copied when the current part was
    542     *                       copied
    543     * @param originalLength the original length of the class full name,
    544     *                       which is abbreviated
    545     * @param desiredLength  the desired length of the abbreviated class
    546     *                       name
    547     * @return {@code true} if it can be kept in its original length
    548     * {@code false} if the current part has to be abbreviated and
    549     */
    550    private static boolean useFull(final int runAheadTarget,
    551                                   final int source,
    552                                   final int originalLength,
    553                                   final int desiredLength) {
    554        return source >= originalLength ||
    555            runAheadTarget + originalLength - source <= desiredLength;
    556    }
    557
    558    // Superclasses/Superinterfaces
    559    // ----------------------------------------------------------------------
    560    /**
    561     * <p>Gets a {@code List} of superclasses for the given class.</p>
    562     *
    563     * @param cls  the class to look up, may be {@code null}
    564     * @return the {@code List} of superclasses in order going up from this one
    565     *  {@code null} if null input
    566     */
    567    public static List<Class<?>> getAllSuperclasses(final Class<?> cls) {
    568        if (cls == null) {
    569            return null;
    570        }
    571        final List<Class<?>> classes = new ArrayList<>();
    572        Class<?> superclass = cls.getSuperclass();
    573        while (superclass != null) {
    574            classes.add(superclass);
    575            superclass = superclass.getSuperclass();
    576        }
    577        return classes;
    578    }
    579
    580    /**
    581     * <p>Gets a {@code List} of all interfaces implemented by the given
    582     * class and its superclasses.</p>
    583     *
    584     * <p>The order is determined by looking through each interface in turn as
    585     * declared in the source file and following its hierarchy up. Then each
    586     * superclass is considered in the same way. Later duplicates are ignored,
    587     * so the order is maintained.</p>
    588     *
    589     * @param cls  the class to look up, may be {@code null}
    590     * @return the {@code List} of interfaces in order,
    591     *  {@code null} if null input
    592     */
    593    public static List<Class<?>> getAllInterfaces(final Class<?> cls) {
    594        if (cls == null) {
    595            return null;
    596        }
    597
    598        final LinkedHashSet<Class<?>> interfacesFound = new LinkedHashSet<>();
    599        getAllInterfaces(cls, interfacesFound);
    600
    601        return new ArrayList<>(interfacesFound);
    602    }
    603
    604    /**
    605     * Gets the interfaces for the specified class.
    606     *
    607     * @param cls  the class to look up, may be {@code null}
    608     * @param interfacesFound the {@code Set} of interfaces for the class
    609     */
    610    private static void getAllInterfaces(Class<?> cls, final HashSet<Class<?>> interfacesFound) {
    611        while (cls != null) {
    612            final Class<?>[] interfaces = cls.getInterfaces();
    613
    614            for (final Class<?> i : interfaces) {
    615                if (interfacesFound.add(i)) {
    616                    getAllInterfaces(i, interfacesFound);
    617                }
    618            }
    619
    620            cls = cls.getSuperclass();
    621         }
    622     }
    623
    624    // Convert list
    625    // ----------------------------------------------------------------------
    626    /**
    627     * <p>Given a {@code List} of class names, this method converts them into classes.</p>
    628     *
    629     * <p>A new {@code List} is returned. If the class name cannot be found, {@code null}
    630     * is stored in the {@code List}. If the class name in the {@code List} is
    631     * {@code null}, {@code null} is stored in the output {@code List}.</p>
    632     *
    633     * @param classNames  the classNames to change
    634     * @return a {@code List} of Class objects corresponding to the class names,
    635     *  {@code null} if null input
    636     * @throws ClassCastException if classNames contains a non String entry
    637     */
    638    public static List<Class<?>> convertClassNamesToClasses(final List<String> classNames) {
    639        if (classNames == null) {
    640            return null;
    641        }
    642        final List<Class<?>> classes = new ArrayList<>(classNames.size());
    643        for (final String className : classNames) {
    644            try {
    645                classes.add(Class.forName(className));
    646            } catch (final Exception ex) {
    647                classes.add(null);
    648            }
    649        }
    650        return classes;
    651    }
    652
    653    /**
    654     * <p>Given a {@code List} of {@code Class} objects, this method converts
    655     * them into class names.</p>
    656     *
    657     * <p>A new {@code List} is returned. {@code null} objects will be copied into
    658     * the returned list as {@code null}.</p>
    659     *
    660     * @param classes  the classes to change
    661     * @return a {@code List} of class names corresponding to the Class objects,
    662     *  {@code null} if null input
    663     * @throws ClassCastException if {@code classes} contains a non-{@code Class} entry
    664     */
    665    public static List<String> convertClassesToClassNames(final List<Class<?>> classes) {
    666        if (classes == null) {
    667            return null;
    668        }
    669        final List<String> classNames = new ArrayList<>(classes.size());
    670        for (final Class<?> cls : classes) {
    671            if (cls == null) {
    672                classNames.add(null);
    673            } else {
    674                classNames.add(cls.getName());
    675            }
    676        }
    677        return classNames;
    678    }
    679
    680    // Is assignable
    681    // ----------------------------------------------------------------------
    682    /**
    683     * <p>Checks if an array of Classes can be assigned to another array of Classes.</p>
    684     *
    685     * <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each
    686     * Class pair in the input arrays. It can be used to check if a set of arguments
    687     * (the first parameter) are suitably compatible with a set of method parameter types
    688     * (the second parameter).</p>
    689     *
    690     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this
    691     * method takes into account widenings of primitive classes and
    692     * {@code null}s.</p>
    693     *
    694     * <p>Primitive widenings allow an int to be assigned to a {@code long},
    695     * {@code float} or {@code double}. This method returns the correct
    696     * result for these cases.</p>
    697     *
    698     * <p>{@code Null} may be assigned to any reference type. This method will
    699     * return {@code true} if {@code null} is passed in and the toClass is
    700     * non-primitive.</p>
    701     *
    702     * <p>Specifically, this method tests whether the type represented by the
    703     * specified {@code Class} parameter can be converted to the type
    704     * represented by this {@code Class} object via an identity conversion
    705     * widening primitive or widening reference conversion. See
    706     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,
    707     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
    708     *
    709     * <p><strong>Since Lang 3.0,</strong> this method will default behavior for
    710     * calculating assignability between primitive and wrapper types <em>corresponding
    711     * to the running Java version</em>; i.e. autoboxing will be the default
    712     * behavior in VMs running Java versions &gt; 1.5.</p>
    713     *
    714     * @param classArray  the array of Classes to check, may be {@code null}
    715     * @param toClassArray  the array of Classes to try to assign into, may be {@code null}
    716     * @return {@code true} if assignment possible
    717     */
    718    public static boolean isAssignable(final Class<?>[] classArray, final Class<?>... toClassArray) {
    719        return isAssignable(classArray, toClassArray, true);
    720    }
    721
    722    /**
    723     * <p>Checks if an array of Classes can be assigned to another array of Classes.</p>
    724     *
    725     * <p>This method calls {@link #isAssignable(Class, Class) isAssignable} for each
    726     * Class pair in the input arrays. It can be used to check if a set of arguments
    727     * (the first parameter) are suitably compatible with a set of method parameter types
    728     * (the second parameter).</p>
    729     *
    730     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this
    731     * method takes into account widenings of primitive classes and
    732     * {@code null}s.</p>
    733     *
    734     * <p>Primitive widenings allow an int to be assigned to a {@code long},
    735     * {@code float} or {@code double}. This method returns the correct
    736     * result for these cases.</p>
    737     *
    738     * <p>{@code Null} may be assigned to any reference type. This method will
    739     * return {@code true} if {@code null} is passed in and the toClass is
    740     * non-primitive.</p>
    741     *
    742     * <p>Specifically, this method tests whether the type represented by the
    743     * specified {@code Class} parameter can be converted to the type
    744     * represented by this {@code Class} object via an identity conversion
    745     * widening primitive or widening reference conversion. See
    746     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,
    747     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
    748     *
    749     * @param classArray  the array of Classes to check, may be {@code null}
    750     * @param toClassArray  the array of Classes to try to assign into, may be {@code null}
    751     * @param autoboxing  whether to use implicit autoboxing/unboxing between primitives and wrappers
    752     * @return {@code true} if assignment possible
    753     */
    754    public static boolean isAssignable(Class<?>[] classArray, Class<?>[] toClassArray, final boolean autoboxing) {
    755        if (!ArrayUtils.isSameLength(classArray, toClassArray)) {
    756            return false;
    757        }
    758        if (classArray == null) {
    759            classArray = ArrayUtils.EMPTY_CLASS_ARRAY;
    760        }
    761        if (toClassArray == null) {
    762            toClassArray = ArrayUtils.EMPTY_CLASS_ARRAY;
    763        }
    764        for (int i = 0; i < classArray.length; i++) {
    765            if (!isAssignable(classArray[i], toClassArray[i], autoboxing)) {
    766                return false;
    767            }
    768        }
    769        return true;
    770    }
    771
    772    /**
    773     * Returns whether the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    774     * {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    775     *
    776     * @param type
    777     *            The class to query or null.
    778     * @return true if the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    779     *         {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    780     * @since 3.1
    781     */
    782    public static boolean isPrimitiveOrWrapper(final Class<?> type) {
    783        if (type == null) {
    784            return false;
    785        }
    786        return type.isPrimitive() || isPrimitiveWrapper(type);
    787    }
    788
    789    /**
    790     * Returns whether the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character}, {@link Short},
    791     * {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    792     *
    793     * @param type
    794     *            The class to query or null.
    795     * @return true if the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character}, {@link Short},
    796     *         {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    797     * @since 3.1
    798     */
    799    public static boolean isPrimitiveWrapper(final Class<?> type) {
    800        return wrapperPrimitiveMap.containsKey(type);
    801    }
    802
    803    /**
    804     * <p>Checks if one {@code Class} can be assigned to a variable of
    805     * another {@code Class}.</p>
    806     *
    807     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method,
    808     * this method takes into account widenings of primitive classes and
    809     * {@code null}s.</p>
    810     *
    811     * <p>Primitive widenings allow an int to be assigned to a long, float or
    812     * double. This method returns the correct result for these cases.</p>
    813     *
    814     * <p>{@code Null} may be assigned to any reference type. This method
    815     * will return {@code true} if {@code null} is passed in and the
    816     * toClass is non-primitive.</p>
    817     *
    818     * <p>Specifically, this method tests whether the type represented by the
    819     * specified {@code Class} parameter can be converted to the type
    820     * represented by this {@code Class} object via an identity conversion
    821     * widening primitive or widening reference conversion. See
    822     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,
    823     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
    824     *
    825     * <p><strong>Since Lang 3.0,</strong> this method will default behavior for
    826     * calculating assignability between primitive and wrapper types <em>corresponding
    827     * to the running Java version</em>; i.e. autoboxing will be the default
    828     * behavior in VMs running Java versions &gt; 1.5.</p>
    829     *
    830     * @param cls  the Class to check, may be null
    831     * @param toClass  the Class to try to assign into, returns false if null
    832     * @return {@code true} if assignment possible
    833     */
    834    public static boolean isAssignable(final Class<?> cls, final Class<?> toClass) {
    835        return isAssignable(cls, toClass, true);
    836    }
    837
    838    /**
    839     * <p>Checks if one {@code Class} can be assigned to a variable of
    840     * another {@code Class}.</p>
    841     *
    842     * <p>Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method,
    843     * this method takes into account widenings of primitive classes and
    844     * {@code null}s.</p>
    845     *
    846     * <p>Primitive widenings allow an int to be assigned to a long, float or
    847     * double. This method returns the correct result for these cases.</p>
    848     *
    849     * <p>{@code Null} may be assigned to any reference type. This method
    850     * will return {@code true} if {@code null} is passed in and the
    851     * toClass is non-primitive.</p>
    852     *
    853     * <p>Specifically, this method tests whether the type represented by the
    854     * specified {@code Class} parameter can be converted to the type
    855     * represented by this {@code Class} object via an identity conversion
    856     * widening primitive or widening reference conversion. See
    857     * <em><a href="http://docs.oracle.com/javase/specs/">The Java Language Specification</a></em>,
    858     * sections 5.1.1, 5.1.2 and 5.1.4 for details.</p>
    859     *
    860     * @param cls  the Class to check, may be null
    861     * @param toClass  the Class to try to assign into, returns false if null
    862     * @param autoboxing  whether to use implicit autoboxing/unboxing between primitives and wrappers
    863     * @return {@code true} if assignment possible
    864     */
    865    public static boolean isAssignable(Class<?> cls, final Class<?> toClass, final boolean autoboxing) {
    866        if (toClass == null) {
    867            return false;
    868        }
    869        // have to check for null, as isAssignableFrom doesn't
    870        if (cls == null) {
    871            return !toClass.isPrimitive();
    872        }
    873        //autoboxing:
    874        if (autoboxing) {
    875            if (cls.isPrimitive() && !toClass.isPrimitive()) {
    876                cls = primitiveToWrapper(cls);
    877                if (cls == null) {
    878                    return false;
    879                }
    880            }
    881            if (toClass.isPrimitive() && !cls.isPrimitive()) {
    882                cls = wrapperToPrimitive(cls);
    883                if (cls == null) {
    884                    return false;
    885                }
    886            }
    887        }
    888        if (cls.equals(toClass)) {
    889            return true;
    890        }
    891        if (cls.isPrimitive()) {
    892            if (!toClass.isPrimitive()) {
    893                return false;
    894            }
    895            if (Integer.TYPE.equals(cls)) {
    896                return Long.TYPE.equals(toClass)
    897                    || Float.TYPE.equals(toClass)
    898                    || Double.TYPE.equals(toClass);
    899            }
    900            if (Long.TYPE.equals(cls)) {
    901                return Float.TYPE.equals(toClass)
    902                    || Double.TYPE.equals(toClass);
    903            }
    904            if (Boolean.TYPE.equals(cls)) {
    905                return false;
    906            }
    907            if (Double.TYPE.equals(cls)) {
    908                return false;
    909            }
    910            if (Float.TYPE.equals(cls)) {
    911                return Double.TYPE.equals(toClass);
    912            }
    913            if (Character.TYPE.equals(cls)) {
    914                return Integer.TYPE.equals(toClass)
    915                    || Long.TYPE.equals(toClass)
    916                    || Float.TYPE.equals(toClass)
    917                    || Double.TYPE.equals(toClass);
    918            }
    919            if (Short.TYPE.equals(cls)) {
    920                return Integer.TYPE.equals(toClass)
    921                    || Long.TYPE.equals(toClass)
    922                    || Float.TYPE.equals(toClass)
    923                    || Double.TYPE.equals(toClass);
    924            }
    925            if (Byte.TYPE.equals(cls)) {
    926                return Short.TYPE.equals(toClass)
    927                    || Integer.TYPE.equals(toClass)
    928                    || Long.TYPE.equals(toClass)
    929                    || Float.TYPE.equals(toClass)
    930                    || Double.TYPE.equals(toClass);
    931            }
    932            // should never get here
    933            return false;
    934        }
    935        return toClass.isAssignableFrom(cls);
    936    }
    937
    938    /**
    939     * <p>Converts the specified primitive Class object to its corresponding
    940     * wrapper Class object.</p>
    941     *
    942     * <p>NOTE: From v2.2, this method handles {@code Void.TYPE},
    943     * returning {@code Void.TYPE}.</p>
    944     *
    945     * @param cls  the class to convert, may be null
    946     * @return the wrapper class for {@code cls} or {@code cls} if
    947     * {@code cls} is not a primitive. {@code null} if null input.
    948     * @since 2.1
    949     */
    950    public static Class<?> primitiveToWrapper(final Class<?> cls) {
    951        Class<?> convertedClass = cls;
    952        if (cls != null && cls.isPrimitive()) {
    953            convertedClass = primitiveWrapperMap.get(cls);
    954        }
    955        return convertedClass;
    956    }
    957
    958    /**
    959     * <p>Converts the specified array of primitive Class objects to an array of
    960     * its corresponding wrapper Class objects.</p>
    961     *
    962     * @param classes  the class array to convert, may be null or empty
    963     * @return an array which contains for each given class, the wrapper class or
    964     * the original class if class is not a primitive. {@code null} if null input.
    965     * Empty array if an empty array passed in.
    966     * @since 2.1
    967     */
    968    public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {
    969        if (classes == null) {
    970            return null;
    971        }
    972
    973        if (classes.length == 0) {
    974            return classes;
    975        }
    976
    977        final Class<?>[] convertedClasses = new Class[classes.length];
    978        for (int i = 0; i < classes.length; i++) {
    979            convertedClasses[i] = primitiveToWrapper(classes[i]);
    980        }
    981        return convertedClasses;
    982    }
    983
    984    /**
    985     * <p>Converts the specified wrapper class to its corresponding primitive
    986     * class.</p>
    987     *
    988     * <p>This method is the counter part of {@code primitiveToWrapper()}.
    989     * If the passed in class is a wrapper class for a primitive type, this
    990     * primitive type will be returned (e.g. {@code Integer.TYPE} for
    991     * {@code Integer.class}). For other classes, or if the parameter is
    992     * <b>null</b>, the return value is <b>null</b>.</p>
    993     *
    994     * @param cls the class to convert, may be <b>null</b>
    995     * @return the corresponding primitive type if {@code cls} is a
    996     * wrapper class, <b>null</b> otherwise
    997     * @see #primitiveToWrapper(Class)
    998     * @since 2.4
    999     */
    1000    public static Class<?> wrapperToPrimitive(final Class<?> cls) {
    1001        return wrapperPrimitiveMap.get(cls);
    1002    }
    1003
    1004    /**
    1005     * <p>Converts the specified array of wrapper Class objects to an array of
    1006     * its corresponding primitive Class objects.</p>
    1007     *
    1008     * <p>This method invokes {@code wrapperToPrimitive()} for each element
    1009     * of the passed in array.</p>
    1010     *
    1011     * @param classes  the class array to convert, may be null or empty
    1012     * @return an array which contains for each given class, the primitive class or
    1013     * <b>null</b> if the original class is not a wrapper class. {@code null} if null input.
    1014     * Empty array if an empty array passed in.
    1015     * @see #wrapperToPrimitive(Class)
    1016     * @since 2.4
    1017     */
    1018    public static Class<?>[] wrappersToPrimitives(final Class<?>... classes) {
    1019        if (classes == null) {
    1020            return null;
    1021        }
    1022
    1023        if (classes.length == 0) {
    1024            return classes;
    1025        }
    1026
    1027        final Class<?>[] convertedClasses = new Class[classes.length];
    1028        for (int i = 0; i < classes.length; i++) {
    1029            convertedClasses[i] = wrapperToPrimitive(classes[i]);
    1030        }
    1031        return convertedClasses;
    1032    }
    1033
    1034    // Inner class
    1035    // ----------------------------------------------------------------------
    1036    /**
    1037     * <p>Is the specified class an inner class or static nested class.</p>
    1038     *
    1039     * @param cls  the class to check, may be null
    1040     * @return {@code true} if the class is an inner or static nested class,
    1041     *  false if not or {@code null}
    1042     */
    1043    public static boolean isInnerClass(final Class<?> cls) {
    1044        return cls != null && cls.getEnclosingClass() != null;
    1045    }
    1046
    1047    // Class loading
    1048    // ----------------------------------------------------------------------
    1049    /**
    1050     * Returns the class represented by {@code className} using the
    1051     * {@code classLoader}.  This implementation supports the syntaxes
    1052     * "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    1053     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    1054     *
    1055     * @param classLoader  the class loader to use to load the class
    1056     * @param className  the class name
    1057     * @param initialize  whether the class must be initialized
    1058     * @return the class represented by {@code className} using the {@code classLoader}
    1059     * @throws ClassNotFoundException if the class is not found
    1060     */
    1061    public static Class<?> getClass(
    1062            final ClassLoader classLoader, final String className, final boolean initialize) throws ClassNotFoundException {
    1063        try {
    1064            final Class<?> clazz;
    1065            if (namePrimitiveMap.containsKey(className)) {
    1066                clazz = namePrimitiveMap.get(className);
    1067            } else {
    1068                clazz = Class.forName(toCanonicalName(className), initialize, classLoader);
    1069            }
    1070            return clazz;
    1071        } catch (final ClassNotFoundException ex) {
    1072            // allow path separators (.) as inner class name separators
    1073            final int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    1074
    1075            if (lastDotIndex != -1) {
    1076                try {
    1077                    return getClass(classLoader, className.substring(0, lastDotIndex) +
    1078                            INNER_CLASS_SEPARATOR_CHAR + className.substring(lastDotIndex + 1),
    1079                            initialize);
    1080                } catch (final ClassNotFoundException ex2) { // NOPMD
    1081                    // ignore exception
    1082                }
    1083            }
    1084
    1085            throw ex;
    1086        }
    1087    }
    1088
    1089    /**
    1090     * Returns the (initialized) class represented by {@code className}
    1091     * using the {@code classLoader}.  This implementation supports
    1092     * the syntaxes "{@code java.util.Map.Entry[]}",
    1093     * "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}",
    1094     * and "{@code [Ljava.util.Map$Entry;}".
    1095     *
    1096     * @param classLoader  the class loader to use to load the class
    1097     * @param className  the class name
    1098     * @return the class represented by {@code className} using the {@code classLoader}
    1099     * @throws ClassNotFoundException if the class is not found
    1100     */
    1101    public static Class<?> getClass(final ClassLoader classLoader, final String className) throws ClassNotFoundException {
    1102        return getClass(classLoader, className, true);
    1103    }
    1104
    1105    /**
    1106     * Returns the (initialized) class represented by {@code className}
    1107     * using the current thread's context class loader. This implementation
    1108     * supports the syntaxes "{@code java.util.Map.Entry[]}",
    1109     * "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}",
    1110     * and "{@code [Ljava.util.Map$Entry;}".
    1111     *
    1112     * @param className  the class name
    1113     * @return the class represented by {@code className} using the current thread's context class loader
    1114     * @throws ClassNotFoundException if the class is not found
    1115     */
    1116    public static Class<?> getClass(final String className) throws ClassNotFoundException {
    1117        return getClass(className, true);
    1118    }
    1119
    1120    /**
    1121     * Returns the class represented by {@code className} using the
    1122     * current thread's context class loader. This implementation supports the
    1123     * syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    1124     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    1125     *
    1126     * @param className  the class name
    1127     * @param initialize  whether the class must be initialized
    1128     * @return the class represented by {@code className} using the current thread's context class loader
    1129     * @throws ClassNotFoundException if the class is not found
    1130     */
    1131    public static Class<?> getClass(final String className, final boolean initialize) throws ClassNotFoundException {
    1132        final ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
    1133        final ClassLoader loader = contextCL == null ? ClassUtils.class.getClassLoader() : contextCL;
    1134        return getClass(loader, className, initialize);
    1135    }
    1136
    1137    // Public method
    1138    // ----------------------------------------------------------------------
    1139    /**
    1140     * <p>Returns the desired Method much like {@code Class.getMethod}, however
    1141     * it ensures that the returned Method is from a public class or interface and not
    1142     * from an anonymous inner class. This means that the Method is invokable and
    1143     * doesn't fall foul of Java bug
    1144     * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4071957">4071957</a>).</p>
    1145     *
    1146     *  <pre>
    1147     *  <code>Set set = Collections.unmodifiableSet(...);
    1148     *  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);
    1149     *  Object result = method.invoke(set, new Object[]);</code>
    1150     *  </pre>
    1151     *
    1152     * @param cls  the class to check, not null
    1153     * @param methodName  the name of the method
    1154     * @param parameterTypes  the list of parameters
    1155     * @return the method
    1156     * @throws NullPointerException if the class is null
    1157     * @throws SecurityException if a security violation occurred
    1158     * @throws NoSuchMethodException if the method is not found in the given class
    1159     *  or if the method doesn't conform with the requirements
    1160     */
    1161    public static Method getPublicMethod(final Class<?> cls, final String methodName, final Class<?>... parameterTypes)
    1162            throws NoSuchMethodException {
    1163
    1164        final Method declaredMethod = cls.getMethod(methodName, parameterTypes);
    1165        if (Modifier.isPublic(declaredMethod.getDeclaringClass().getModifiers())) {
    1166            return declaredMethod;
    1167        }
    1168
    1169        final List<Class<?>> candidateClasses = new ArrayList<>(getAllInterfaces(cls));
    1170        candidateClasses.addAll(getAllSuperclasses(cls));
    1171
    1172        for (final Class<?> candidateClass : candidateClasses) {
    1173            if (!Modifier.isPublic(candidateClass.getModifiers())) {
    1174                continue;
    1175            }
    1176            final Method candidateMethod;
    1177            try {
    1178                candidateMethod = candidateClass.getMethod(methodName, parameterTypes);
    1179            } catch (final NoSuchMethodException ex) {
    1180                continue;
    1181            }
    1182            if (Modifier.isPublic(candidateMethod.getDeclaringClass().getModifiers())) {
    1183                return candidateMethod;
    1184            }
    1185        }
    1186
    1187        throw new NoSuchMethodException("Can't find a public method for " +
    1188                methodName + " " + ArrayUtils.toString(parameterTypes));
    1189    }
    1190
    1191    // ----------------------------------------------------------------------
    1192    /**
    1193     * Converts a class name to a JLS style class name.
    1194     *
    1195     * @param className  the class name
    1196     * @return the converted name
    1197     */
    1198    private static String toCanonicalName(String className) {
    1199        className = StringUtils.deleteWhitespace(className);
    1200        Validate.notNull(className, "className");
    1201        if (className.endsWith("[]")) {
    1202            final StringBuilder classNameBuffer = new StringBuilder();
    1203            while (className.endsWith("[]")) {
    1204                className = className.substring(0, className.length() - 2);
    1205                classNameBuffer.append("[");
    1206            }
    1207            final String abbreviation = abbreviationMap.get(className);
    1208            if (abbreviation != null) {
    1209                classNameBuffer.append(abbreviation);
    1210            } else {
    1211                classNameBuffer.append("L").append(className).append(";");
    1212            }
    1213            className = classNameBuffer.toString();
    1214        }
    1215        return className;
    1216    }
    1217
    1218    /**
    1219     * <p>Converts an array of {@code Object} in to an array of {@code Class} objects.
    1220     * If any of these objects is null, a null element will be inserted into the array.</p>
    1221     *
    1222     * <p>This method returns {@code null} for a {@code null} input array.</p>
    1223     *
    1224     * @param array an {@code Object} array
    1225     * @return a {@code Class} array, {@code null} if null array input
    1226     * @since 2.4
    1227     */
    1228    public static Class<?>[] toClass(final Object... array) {
    1229        if (array == null) {
    1230            return null;
    1231        } else if (array.length == 0) {
    1232            return ArrayUtils.EMPTY_CLASS_ARRAY;
    1233        }
    1234        final Class<?>[] classes = new Class[array.length];
    1235        for (int i = 0; i < array.length; i++) {
    1236            classes[i] = array[i] == null ? null : array[i].getClass();
    1237        }
    1238        return classes;
    1239    }
    1240
    1241    // Short canonical name
    1242    // ----------------------------------------------------------------------
    1243    /**
    1244     * <p>Gets the canonical name minus the package name for an {@code Object}.</p>
    1245     *
    1246     * @param object  the class to get the short name for, may be null
    1247     * @param valueIfNull  the value to return if null
    1248     * @return the canonical name of the object without the package name, or the null value
    1249     * @since 2.4
    1250     */
    1251    public static String getShortCanonicalName(final Object object, final String valueIfNull) {
    1252        if (object == null) {
    1253            return valueIfNull;
    1254        }
    1255        return getShortCanonicalName(object.getClass().getName());
    1256    }
    1257
    1258    /**
    1259     * <p>Gets the canonical class name for a {@code Class}.</p>
    1260     *
    1261     * @param cls the class for which to get the canonical class name; may be null
    1262     * @return the canonical name of the class, or the empty String
    1263     * @since 3.7
    1264     * @see Class#getCanonicalName()
    1265     */
    1266    public static String getCanonicalName(final Class<?> cls) {
    1267        return getCanonicalName(cls, StringUtils.EMPTY);
    1268    }
    1269
    1270    /**
    1271     * <p>Gets the canonical name for a {@code Class}.</p>
    1272     *
    1273     * @param cls the class for which to get the canonical class name; may be null
    1274     * @param valueIfNull  the return value if null
    1275     * @return the canonical name of the class, or {@code valueIfNull}
    1276     * @since 3.7
    1277     * @see Class#getCanonicalName()
    1278     */
    1279    public static String getCanonicalName(final Class<?> cls, final String valueIfNull) {
    1280        if (cls == null) {
    1281            return valueIfNull;
    1282        }
    1283        final String canonicalName = cls.getCanonicalName();
    1284        return canonicalName == null ? valueIfNull : canonicalName;
    1285    }
    1286
    1287    /**
    1288     * <p>Gets the canonical name for an {@code Object}.</p>
    1289     *
    1290     * @param object the object for which to get the canonical class name; may be null
    1291     * @return the canonical name of the object, or the empty String
    1292     * @since 3.7
    1293     * @see Class#getCanonicalName()
    1294     */
    1295    public static String getCanonicalName(final Object object) {
    1296        return getCanonicalName(object, StringUtils.EMPTY);
    1297    }
    1298
    1299    /**
    1300     * <p>Gets the canonical name for an {@code Object}.</p>
    1301     *
    1302     * @param object the object for which to get the canonical class name; may be null
    1303     * @param valueIfNull  the return value if null
    1304     * @return the canonical name of the object or {@code valueIfNull}
    1305     * @since 3.7
    1306     * @see Class#getCanonicalName()
    1307     */
    1308    public static String getCanonicalName(final Object object, final String valueIfNull) {
    1309        if (object == null) {
    1310            return valueIfNull;
    1311        }
    1312        final String canonicalName = object.getClass().getCanonicalName();
    1313        return canonicalName == null ? valueIfNull : canonicalName;
    1314    }
    1315
    1316    /**
    1317     * <p>Gets the canonical name minus the package name from a {@code Class}.</p>
    1318     *
    1319     * @param cls the class for which to get the short canonical class name; may be null
    1320     * @return the canonical name without the package name or an empty string
    1321     * @since 2.4
    1322     */
    1323    public static String getShortCanonicalName(final Class<?> cls) {
    1324        if (cls == null) {
    1325            return StringUtils.EMPTY;
    1326        }
    1327        return getShortCanonicalName(cls.getName());
    1328    }
    1329
    1330    /**
    1331     * <p>Gets the canonical name minus the package name from a String.</p>
    1332     *
    1333     * <p>The string passed in is assumed to be a class name - it is not checked.</p>
    1334     *
    1335     * <p>Note that this method is mainly designed to handle the arrays and primitives properly.
    1336     * If the class is an inner class then the result value will not contain the outer classes.
    1337     * This way the behavior of this method is different from {@link #getShortClassName(String)}.
    1338     * The argument in that case is class name and not canonical name and the return value
    1339     * retains the outer classes.</p>
    1340     *
    1341     * <p>Note that there is no way to reliably identify the part of the string representing the
    1342     * package hierarchy and the part that is the outer class or classes in case of an inner class.
    1343     * Trying to find the class would require reflective call and the class itself may not even be
    1344     * on the class path. Relying on the fact that class names start with capital letter and packages
    1345     * with lower case is heuristic.</p>
    1346     *
    1347     * <p>It is recommended to use {@link #getShortClassName(String)} for cases when the class
    1348     * is an inner class and use this method for cases it is designed for.</p>
    1349     *
    1350     * <table>
    1351     * <caption>Examples</caption>
    1352     * <tr><td>return value</td><td>input</td></tr>
    1353     * <tr><td>{@code ""}</td><td>{@code (String)null}</td></tr>
    1354     * <tr><td>{@code "Map.Entry"}</td><td>{@code java.util.Map.Entry.class.getName()}</td></tr>
    1355     * <tr><td>{@code "Entry"}</td><td>{@code java.util.Map.Entry.class.getCanonicalName()}</td></tr>
    1356     * <tr><td>{@code "ClassUtils"}</td><td>{@code "org.apache.commons.lang3.ClassUtils"}</td></tr>
    1357     * <tr><td>{@code "ClassUtils[]"}</td><td>{@code "[Lorg.apache.commons.lang3.ClassUtils;"}</td></tr>
    1358     * <tr><td>{@code "ClassUtils[][]"}</td><td>{@code "[[Lorg.apache.commons.lang3.ClassUtils;"}</td></tr>
    1359     * <tr><td>{@code "ClassUtils[]"}</td><td>{@code "org.apache.commons.lang3.ClassUtils[]"}</td></tr>
    1360     * <tr><td>{@code "ClassUtils[][]"}</td><td>{@code "org.apache.commons.lang3.ClassUtils[][]"}</td></tr>
    1361     * <tr><td>{@code "int[]"}</td><td>{@code "[I"}</td></tr>
    1362     * <tr><td>{@code "int[]"}</td><td>{@code int[].class.getCanonicalName()}</td></tr>
    1363     * <tr><td>{@code "int[]"}</td><td>{@code int[].class.getName()}</td></tr>
    1364     * <tr><td>{@code "int[][]"}</td><td>{@code "[[I"}</td></tr>
    1365     * <tr><td>{@code "int[]"}</td><td>{@code "int[]"}</td></tr>
    1366     * <tr><td>{@code "int[][]"}</td><td>{@code "int[][]"}</td></tr>
    1367     * </table>
    1368     *
    1369     * @param canonicalName  the class name to get the short name for
    1370     * @return the canonical name of the class without the package name or an empty string
    1371     * @since 2.4
    1372     */
    1373    public static String getShortCanonicalName(final String canonicalName) {
    1374        return getShortClassName(getCanonicalName(canonicalName));
    1375    }
    1376
    1377    // Package name
    1378    // ----------------------------------------------------------------------
    1379    /**
    1380     * <p>Gets the package name from the class name of an {@code Object}.</p>
    1381     *
    1382     * @param object  the class to get the package name for, may be null
    1383     * @param valueIfNull  the value to return if null
    1384     * @return the package name of the object, or the null value
    1385     * @since 2.4
    1386     */
    1387    public static String getPackageCanonicalName(final Object object, final String valueIfNull) {
    1388        if (object == null) {
    1389            return valueIfNull;
    1390        }
    1391        return getPackageCanonicalName(object.getClass().getName());
    1392    }
    1393
    1394    /**
    1395     * <p>Gets the package name from the canonical name of a {@code Class}.</p>
    1396     *
    1397     * @param cls  the class to get the package name for, may be {@code null}.
    1398     * @return the package name or an empty string
    1399     * @since 2.4
    1400     */
    1401    public static String getPackageCanonicalName(final Class<?> cls) {
    1402        if (cls == null) {
    1403            return StringUtils.EMPTY;
    1404        }
    1405        return getPackageCanonicalName(cls.getName());
    1406    }
    1407
    1408    /**
    1409     * <p>Gets the package name from the class name. </p>
    1410     *
    1411     * <p>The string passed in is assumed to be a class name - it is not checked.</p>
    1412     * <p>If the class is in the default package, return an empty string.</p>
    1413     *
    1414     * @param name  the name to get the package name for, may be {@code null}
    1415     * @return the package name or an empty string
    1416     * @since 2.4
    1417     */
    1418    public static String getPackageCanonicalName(final String name) {
    1419        return getPackageName(getCanonicalName(name));
    1420    }
    1421
    1422    /**
    1423     * <p>Converts a given name of class into canonical format.
    1424     * If name of class is not a name of array class it returns
    1425     * unchanged name.</p>
    1426     *
    1427     * <p>The method does not change the {@code $} separators in case
    1428     * the class is inner class.</p>
    1429     *
    1430     * <p>Example:
    1431     * <ul>
    1432     * <li>{@code getCanonicalName("[I") = "int[]"}</li>
    1433     * <li>{@code getCanonicalName("[Ljava.lang.String;") = "java.lang.String[]"}</li>
    1434     * <li>{@code getCanonicalName("java.lang.String") = "java.lang.String"}</li>
    1435     * </ul>
    1436     * </p>
    1437     *
    1438     * @param className the name of class
    1439     * @return canonical form of class name
    1440     * @since 2.4
    1441     */
    1442    private static String getCanonicalName(String className) {
    1443        className = StringUtils.deleteWhitespace(className);
    1444        if (className == null) {
    1445            return null;
    1446        }
    1447        int dim = 0;
    1448        while (className.startsWith("[")) {
    1449            dim++;
    1450            className = className.substring(1);
    1451        }
    1452        if (dim < 1) {
    1453            return className;
    1454        }
    1455        if (className.startsWith("L")) {
    1456            className = className.substring(
    1457                1,
    1458                className.endsWith(";")
    1459                    ? className.length() - 1
    1460                    : className.length());
    1461        } else if (!className.isEmpty()) {
    1462            className = reverseAbbreviationMap.get(className.substring(0, 1));
    1463        }
    1464        final StringBuilder canonicalClassNameBuffer = new StringBuilder(className);
    1465        for (int i = 0; i < dim; i++) {
    1466            canonicalClassNameBuffer.append("[]");
    1467        }
    1468        return canonicalClassNameBuffer.toString();
    1469    }
    1470
    1471    /**
    1472     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order,
    1473     * excluding interfaces.
    1474     *
    1475     * @param type the type to get the class hierarchy from
    1476     * @return Iterable an Iterable over the class hierarchy of the given class
    1477     * @since 3.2
    1478     */
    1479    public static Iterable<Class<?>> hierarchy(final Class<?> type) {
    1480        return hierarchy(type, Interfaces.EXCLUDE);
    1481    }
    1482
    1483    /**
    1484     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order.
    1485     *
    1486     * @param type the type to get the class hierarchy from
    1487     * @param interfacesBehavior switch indicating whether to include or exclude interfaces
    1488     * @return Iterable an Iterable over the class hierarchy of the given class
    1489     * @since 3.2
    1490     */
    1491    public static Iterable<Class<?>> hierarchy(final Class<?> type, final Interfaces interfacesBehavior) {
    1492        final Iterable<Class<?>> classes = () -> {
    1493            final MutableObject<Class<?>> next = new MutableObject<>(type);
    1494            return new Iterator<Class<?>>() {
    1495
    1496                @Override
    1497                public boolean hasNext() {
    1498                    return next.getValue() != null;
    1499                }
    1500
    1501                @Override
    1502                public Class<?> next() {
    1503                    final Class<?> result = next.getValue();
    1504                    next.setValue(result.getSuperclass());
    1505                    return result;
    1506                }
    1507
    1508                @Override
    1509                public void remove() {
    1510                    throw new UnsupportedOperationException();
    1511                }
    1512
    1513            };
    1514        };
    1515        if (interfacesBehavior != Interfaces.INCLUDE) {
    1516            return classes;
    1517        }
    1518        return () -> {
    1519            final Set<Class<?>> seenInterfaces = new HashSet<>();
    1520            final Iterator<Class<?>> wrapped = classes.iterator();
    1521
    1522            return new Iterator<Class<?>>() {
    1523                Iterator<Class<?>> interfaces = Collections.<Class<?>>emptySet().iterator();
    1524
    1525                @Override
    1526                public boolean hasNext() {
    1527                    return interfaces.hasNext() || wrapped.hasNext();
    1528                }
    1529
    1530                @Override
    1531                public Class<?> next() {
    1532                    if (interfaces.hasNext()) {
    1533                        final Class<?> nextInterface = interfaces.next();
    1534                        seenInterfaces.add(nextInterface);
    1535                        return nextInterface;
    1536                    }
    1537                    final Class<?> nextSuperclass = wrapped.next();
    1538                    final Set<Class<?>> currentInterfaces = new LinkedHashSet<>();
    1539                    walkInterfaces(currentInterfaces, nextSuperclass);
    1540                    interfaces = currentInterfaces.iterator();
    1541                    return nextSuperclass;
    1542                }
    1543
    1544                private void walkInterfaces(final Set<Class<?>> addTo, final Class<?> c) {
    1545                    for (final Class<?> iface : c.getInterfaces()) {
    1546                        if (!seenInterfaces.contains(iface)) {
    1547                            addTo.add(iface);
    1548                        }
    1549                        walkInterfaces(addTo, iface);
    1550                    }
    1551                }
    1552
    1553                @Override
    1554                public void remove() {
    1555                    throw new UnsupportedOperationException();
    1556                }
    1557
    1558            };
    1559        };
    1560    }
    1561
    1562}