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}