    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 * http://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.commons.compress.utils;
    020
    021import java.io.ByteArrayOutputStream;
    022import java.io.Closeable;
    023import java.io.EOFException;
    024import java.io.File;
    025import java.io.IOException;
    026import java.io.InputStream;
    027import java.io.OutputStream;
    028import java.nio.ByteBuffer;
    029import java.nio.channels.ReadableByteChannel;
    030import java.nio.file.Files;
    031import java.nio.file.LinkOption;
    032
    033/**
    034 * Utility functions
    035 * @Immutable (has mutable data but it is write-only)
    036 */
    037public final class IOUtils {
    038
    039    private static final int COPY_BUF_SIZE = 8024;
    040    private static final int SKIP_BUF_SIZE = 4096;
    041
    042    /**
    043     * Empty array of type {@link LinkOption}.
    044     *
    045     * @since 1.21
    046     */
    047    public static final LinkOption[] EMPTY_LINK_OPTIONS = {};
    048
    049    // This buffer does not need to be synchronized because it is write only; the contents are ignored
    050    // Does not affect Immutability
    051    private static final byte[] SKIP_BUF = new byte[SKIP_BUF_SIZE];
    052
    053    /**
    054     * Closes the given Closeable and swallows any IOException that may occur.
    055     * @param c Closeable to close, can be null
    056     * @since 1.7
    057     */
    058    public static void closeQuietly(final Closeable c) {
    059        if (c != null) {
    060            try {
    061                c.close();
    062            } catch (final IOException ignored) { // NOPMD NOSONAR
    063            }
    064        }
    065    }
    066
    067    /**
    068     * Copies the source file to the given output stream.
    069     * @param sourceFile The file to read.
    070     * @param outputStream The output stream to write.
    071     * @throws IOException if an I/O error occurs when reading or writing.
    072     * @since 1.21
    073     */
    074    public static void copy(final File sourceFile, final OutputStream outputStream) throws IOException {
    075        Files.copy(sourceFile.toPath(), outputStream);
    076    }
    077
    078    /**
    079     * Copies the content of a InputStream into an OutputStream.
    080     * Uses a default buffer size of 8024 bytes.
    081     *
    082     * @param input
    083     *            the InputStream to copy
    084     * @param output
    085     *            the target, may be null to simulate output to dev/null on Linux and NUL on Windows
    086     * @return the number of bytes copied
    087     * @throws IOException
    088     *             if an error occurs
    089     */
    090    public static long copy(final InputStream input, final OutputStream output) throws IOException {
    091        return copy(input, output, COPY_BUF_SIZE);
    092    }
    093
    094    /**
    095     * Copies the content of a InputStream into an OutputStream
    096     *
    097     * @param input
    098     *            the InputStream to copy
    099     * @param output
    100     *            the target, may be null to simulate output to dev/null on Linux and NUL on Windows
    101     * @param bufferSize
    102     *            the buffer size to use, must be bigger than 0
    103     * @return the number of bytes copied
    104     * @throws IOException
    105     *             if an error occurs
    106     * @throws IllegalArgumentException
    107     *             if bufferSize is smaller than or equal to 0
    108     */
    109    public static long copy(final InputStream input, final OutputStream output, final int bufferSize) throws IOException {
    110        if (bufferSize < 1) {
    111            throw new IllegalArgumentException("bufferSize must be bigger than 0");
    112        }
    113        final byte[] buffer = new byte[bufferSize];
    114        int n = 0;
    115        long count = 0;
    116        while (-1 != (n = input.read(buffer))) {
    117            if (output != null) {
    118                output.write(buffer, 0, n);
    119            }
    120            count += n;
    121        }
    122        return count;
    123    }
    124
    125    /**
    126     * Copies part of the content of a InputStream into an OutputStream.
    127     * Uses a default buffer size of 8024 bytes.
    128     *
    129     * @param input
    130     *            the InputStream to copy
    131     * @param output
    132     *            the target Stream
    133     * @param len
    134     *            maximum amount of bytes to copy
    135     * @return the number of bytes copied
    136     * @throws IOException
    137     *             if an error occurs
    138     * @since 1.21
    139     */
    140    public static long copyRange(final InputStream input, final long len, final OutputStream output)
    141        throws IOException {
    142        return copyRange(input, len, output, COPY_BUF_SIZE);
    143    }
    144
    145    /**
    146     * Copies part of the content of a InputStream into an OutputStream
    147     *
    148     * @param input
    149     *            the InputStream to copy
    150     * @param len
    151     *            maximum amount of bytes to copy
    152     * @param output
    153     *            the target, may be null to simulate output to dev/null on Linux and NUL on Windows
    154     * @param bufferSize
    155     *            the buffer size to use, must be bigger than 0
    156     * @return the number of bytes copied
    157     * @throws IOException
    158     *             if an error occurs
    159     * @throws IllegalArgumentException
    160     *             if bufferSize is smaller than or equal to 0
    161     * @since 1.21
    162     */
    163    public static long copyRange(final InputStream input, final long len, final OutputStream output,
    164        final int bufferSize) throws IOException {
    165        if (bufferSize < 1) {
    166            throw new IllegalArgumentException("bufferSize must be bigger than 0");
    167        }
    168        final byte[] buffer = new byte[(int) Math.min(bufferSize, len)];
    169        int n = 0;
    170        long count = 0;
    171        while (count < len && -1 != (n = input.read(buffer, 0, (int) Math.min(len - count, buffer.length)))) {
    172            if (output != null) {
    173                output.write(buffer, 0, n);
    174            }
    175            count += n;
    176        }
    177        return count;
    178    }
    179
    180    /**
    181     * Reads as much from the file as possible to fill the given array.
    182     *
    183     * <p>This method may invoke read repeatedly to fill the array and
    184     * only read less bytes than the length of the array if the end of
    185     * the stream has been reached.</p>
    186     *
    187     * @param file file to read
    188     * @param array buffer to fill
    189     * @return the number of bytes actually read
    190     * @throws IOException on error
    191     * @since 1.20
    192     */
    193    public static int read(final File file, final byte[] array) throws IOException {
    194        try (InputStream inputStream = Files.newInputStream(file.toPath())) {
    195            return readFully(inputStream, array, 0, array.length);
    196        }
    197    }
    198
    199    /**
    200     * Reads as much from input as possible to fill the given array.
    201     *
    202     * <p>This method may invoke read repeatedly to fill the array and
    203     * only read less bytes than the length of the array if the end of
    204     * the stream has been reached.</p>
    205     *
    206     * @param input stream to read from
    207     * @param array buffer to fill
    208     * @return the number of bytes actually read
    209     * @throws IOException on error
    210     */
    211    public static int readFully(final InputStream input, final byte[] array) throws IOException {
    212        return readFully(input, array, 0, array.length);
    213    }
    214
    215    // toByteArray(InputStream) copied from:
    216    // commons/proper/io/trunk/src/main/java/org/apache/commons/io/IOUtils.java?revision=1428941
    217    // January 8th, 2013
    218    //
    219    // Assuming our copy() works just as well as theirs!  :-)
    220
    221    /**
    222     * Reads as much from input as possible to fill the given array
    223     * with the given amount of bytes.
    224     *
    225     * <p>This method may invoke read repeatedly to read the bytes and
    226     * only read less bytes than the requested length if the end of
    227     * the stream has been reached.</p>
    228     *
    229     * @param input stream to read from
    230     * @param array buffer to fill
    231     * @param offset offset into the buffer to start filling at
    232     * @param len of bytes to read
    233     * @return the number of bytes actually read
    234     * @throws IOException
    235     *             if an I/O error has occurred
    236     */
    237    public static int readFully(final InputStream input, final byte[] array, final int offset, final int len)
    238        throws IOException {
    239        if (len < 0 || offset < 0 || len + offset > array.length || len + offset < 0) {
    240            throw new IndexOutOfBoundsException();
    241        }
    242        int count = 0, x = 0;
    243        while (count != len) {
    244            x = input.read(array, offset + count, len - count);
    245            if (x == -1) {
    246                break;
    247            }
    248            count += x;
    249        }
    250        return count;
    251    }
    252
    253    /**
    254     * Reads {@code b.remaining()} bytes from the given channel
    255     * starting at the current channel's position.
    256     *
    257     * <p>This method reads repeatedly from the channel until the
    258     * requested number of bytes are read. This method blocks until
    259     * the requested number of bytes are read, the end of the channel
    260     * is detected, or an exception is thrown.</p>
    261     *
    262     * @param channel the channel to read from
    263     * @param byteBuffer the buffer into which the data is read.
    264     * @throws IOException - if an I/O error occurs.
    265     * @throws EOFException - if the channel reaches the end before reading all the bytes.
    266     */
    267    public static void readFully(final ReadableByteChannel channel, final ByteBuffer byteBuffer) throws IOException {
    268        final int expectedLength = byteBuffer.remaining();
    269        int read = 0;
    270        while (read < expectedLength) {
    271            final int readNow = channel.read(byteBuffer);
    272            if (readNow <= 0) {
    273                break;
    274            }
    275            read += readNow;
    276        }
    277        if (read < expectedLength) {
    278            throw new EOFException();
    279        }
    280    }
    281
    282    /**
    283     * Gets part of the contents of an {@code InputStream} as a {@code byte[]}.
    284     *
    285     * @param input  the {@code InputStream} to read from
    286     * @param len
    287     *            maximum amount of bytes to copy
    288     * @return the requested byte array
    289     * @throws NullPointerException if the input is null
    290     * @throws IOException if an I/O error occurs
    291     * @since 1.21
    292     */
    293    public static byte[] readRange(final InputStream input, final int len) throws IOException {
    294        final ByteArrayOutputStream output = new ByteArrayOutputStream();
    295        copyRange(input, len, output);
    296        return output.toByteArray();
    297    }
    298
    299    /**
    300     * Gets part of the contents of an {@code ReadableByteChannel} as a {@code byte[]}.
    301     *
    302     * @param input  the {@code ReadableByteChannel} to read from
    303     * @param len
    304     *            maximum amount of bytes to copy
    305     * @return the requested byte array
    306     * @throws NullPointerException if the input is null
    307     * @throws IOException if an I/O error occurs
    308     * @since 1.21
    309     */
    310    public static byte[] readRange(final ReadableByteChannel input, final int len) throws IOException {
    311        final ByteArrayOutputStream output = new ByteArrayOutputStream();
    312        final ByteBuffer b = ByteBuffer.allocate(Math.min(len, COPY_BUF_SIZE));
    313        int read = 0;
    314        while (read < len) {
    315            // Make sure we never read more than len bytes
    316            b.limit(Math.min(len - read, b.capacity()));
    317            final int readNow = input.read(b);
    318            if (readNow <= 0) {
    319                break;
    320            }
    321            output.write(b.array(), 0, readNow);
    322            b.rewind();
    323            read += readNow;
    324        }
    325        return output.toByteArray();
    326    }
    327
    328    /**
    329     * Skips the given number of bytes by repeatedly invoking skip on
    330     * the given input stream if necessary.
    331     *
    332     * <p>In a case where the stream's skip() method returns 0 before
    333     * the requested number of bytes has been skip this implementation
    334     * will fall back to using the read() method.</p>
    335     *
    336     * <p>This method will only skip less than the requested number of
    337     * bytes if the end of the input stream has been reached.</p>
    338     *
    339     * @param input stream to skip bytes in
    340     * @param numToSkip the number of bytes to skip
    341     * @return the number of bytes actually skipped
    342     * @throws IOException on error
    343     */
    344    public static long skip(final InputStream input, long numToSkip) throws IOException {
    345        final long available = numToSkip;
    346        while (numToSkip > 0) {
    347            final long skipped = input.skip(numToSkip);
    348            if (skipped == 0) {
    349                break;
    350            }
    351            numToSkip -= skipped;
    352        }
    353
    354        while (numToSkip > 0) {
    355            final int read = readFully(input, SKIP_BUF, 0,
    356                                 (int) Math.min(numToSkip, SKIP_BUF_SIZE));
    357            if (read < 1) {
    358                break;
    359            }
    360            numToSkip -= read;
    361        }
    362        return available - numToSkip;
    363    }
    364
    365    /**
    366     * Gets the contents of an {@code InputStream} as a {@code byte[]}.
    367     * <p>
    368     * This method buffers the input internally, so there is no need to use a
    369     * {@code BufferedInputStream}.
    370     *
    371     * @param input  the {@code InputStream} to read from
    372     * @return the requested byte array
    373     * @throws NullPointerException if the input is null
    374     * @throws IOException if an I/O error occurs
    375     * @since 1.5
    376     */
    377    public static byte[] toByteArray(final InputStream input) throws IOException {
    378        final ByteArrayOutputStream output = new ByteArrayOutputStream();
    379        copy(input, output);
    380        return output.toByteArray();
    381    }
    382
    383    /** Private constructor to prevent instantiation of this utility class. */
    384    private IOUtils(){
    385    }
    386
    387}