    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.io.output;
    018
    019import java.io.BufferedInputStream;
    020import java.io.IOException;
    021import java.io.InputStream;
    022import java.io.OutputStream;
    023
    024/**
    025 * Implements a ThreadSafe version of {@link AbstractByteArrayOutputStream} using instance synchronization.
    026 */
    027//@ThreadSafe
    028public class ByteArrayOutputStream extends AbstractByteArrayOutputStream {
    029
    030    /**
    031     * Fetches entire contents of an {@link InputStream} and represent
    032     * same data as result InputStream.
    033     * <p>
    034     * This method is useful where,
    035     * </p>
    036     * <ul>
    037     * <li>Source InputStream is slow.</li>
    038     * <li>It has network resources associated, so we cannot keep it open for
    039     * long time.</li>
    040     * <li>It has network timeout associated.</li>
    041     * </ul>
    042     * It can be used in favor of {@link #toByteArray()}, since it
    043     * avoids unnecessary allocation and copy of byte[].<br>
    044     * This method buffers the input internally, so there is no need to use a
    045     * {@link BufferedInputStream}.
    046     *
    047     * @param input Stream to be fully buffered.
    048     * @return A fully buffered stream.
    049     * @throws IOException if an I/O error occurs.
    050     * @since 2.0
    051     */
    052    public static InputStream toBufferedInputStream(final InputStream input)
    053            throws IOException {
    054        return toBufferedInputStream(input, DEFAULT_SIZE);
    055    }
    056
    057    /**
    058     * Fetches entire contents of an {@link InputStream} and represent
    059     * same data as result InputStream.
    060     * <p>
    061     * This method is useful where,
    062     * </p>
    063     * <ul>
    064     * <li>Source InputStream is slow.</li>
    065     * <li>It has network resources associated, so we cannot keep it open for
    066     * long time.</li>
    067     * <li>It has network timeout associated.</li>
    068     * </ul>
    069     * It can be used in favor of {@link #toByteArray()}, since it
    070     * avoids unnecessary allocation and copy of byte[].<br>
    071     * This method buffers the input internally, so there is no need to use a
    072     * {@link BufferedInputStream}.
    073     *
    074     * @param input Stream to be fully buffered.
    075     * @param size the initial buffer size
    076     * @return A fully buffered stream.
    077     * @throws IOException if an I/O error occurs.
    078     * @since 2.5
    079     */
    080    public static InputStream toBufferedInputStream(final InputStream input, final int size)
    081        throws IOException {
    082        try (ByteArrayOutputStream output = new ByteArrayOutputStream(size)) {
    083            output.write(input);
    084            return output.toInputStream();
    085        }
    086    }
    087
    088    /**
    089     * Constructs a new byte array output stream. The buffer capacity is
    090     * initially {@value AbstractByteArrayOutputStream#DEFAULT_SIZE} bytes, though its size increases if necessary.
    091     */
    092    public ByteArrayOutputStream() {
    093        this(DEFAULT_SIZE);
    094    }
    095
    096    /**
    097     * Constructs a new byte array output stream, with a buffer capacity of
    098     * the specified size, in bytes.
    099     *
    100     * @param size  the initial size
    101     * @throws IllegalArgumentException if size is negative
    102     */
    103    public ByteArrayOutputStream(final int size) {
    104        if (size < 0) {
    105            throw new IllegalArgumentException("Negative initial size: " + size);
    106        }
    107        synchronized (this) {
    108            needNewBuffer(size);
    109        }
    110    }
    111
    112    /**
    113     * @see java.io.ByteArrayOutputStream#reset()
    114     */
    115    @Override
    116    public synchronized void reset() {
    117        resetImpl();
    118    }
    119
    120    @Override
    121    public synchronized int size() {
    122        return count;
    123    }
    124
    125    @Override
    126    public synchronized byte[] toByteArray() {
    127        return toByteArrayImpl();
    128    }
    129
    130    @Override
    131    public synchronized InputStream toInputStream() {
    132        return toInputStream(java.io.ByteArrayInputStream::new);
    133    }
    134
    135    @Override
    136    public void write(final byte[] b, final int off, final int len) {
    137        if (off < 0
    138                || off > b.length
    139                || len < 0
    140                || off + len > b.length
    141                || off + len < 0) {
    142            throw new IndexOutOfBoundsException();
    143        }
    144        if (len == 0) {
    145            return;
    146        }
    147        synchronized (this) {
    148            writeImpl(b, off, len);
    149        }
    150    }
    151
    152    @Override
    153    public synchronized int write(final InputStream in) throws IOException {
    154        return writeImpl(in);
    155    }
    156
    157    @Override
    158    public synchronized void write(final int b) {
    159        writeImpl(b);
    160    }
    161
    162    @Override
    163    public synchronized void writeTo(final OutputStream out) throws IOException {
    164        writeToImpl(out);
    165    }
    166}