    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 org.apache.commons.io.input.UnsynchronizedByteArrayInputStream;
    020
    021import java.io.IOException;
    022import java.io.InputStream;
    023import java.io.OutputStream;
    024
    025/**
    026 * Implements a version of {@link AbstractByteArrayOutputStream} <b>without</b> any concurrent thread safety.
    027 *
    028 * @since 2.7
    029 */
    030//@NotThreadSafe
    031public final class UnsynchronizedByteArrayOutputStream extends AbstractByteArrayOutputStream {
    032
    033    /**
    034     * Creates a new byte array output stream. The buffer capacity is initially
    035     * {@value AbstractByteArrayOutputStream#DEFAULT_SIZE} bytes, though its size increases if necessary.
    036     */
    037    public UnsynchronizedByteArrayOutputStream() {
    038        this(DEFAULT_SIZE);
    039    }
    040
    041    /**
    042     * Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.
    043     *
    044     * @param size the initial size
    045     * @throws IllegalArgumentException if size is negative
    046     */
    047    public UnsynchronizedByteArrayOutputStream(final int size) {
    048        if (size < 0) {
    049            throw new IllegalArgumentException("Negative initial size: " + size);
    050        }
    051        needNewBuffer(size);
    052    }
    053
    054    @Override
    055    public void write(final byte[] b, final int off, final int len) {
    056        if ((off < 0) || (off > b.length) || (len < 0) || ((off + len) > b.length) || ((off + len) < 0)) {
    057            throw new IndexOutOfBoundsException(String.format("offset=%,d, length=%,d", off, len));
    058        }
    059        if (len == 0) {
    060            return;
    061        }
    062        writeImpl(b, off, len);
    063    }
    064
    065    @Override
    066    public void write(final int b) {
    067        writeImpl(b);
    068    }
    069
    070    @Override
    071    public int write(final InputStream in) throws IOException {
    072        return writeImpl(in);
    073    }
    074
    075    @Override
    076    public int size() {
    077        return count;
    078    }
    079
    080    /**
    081     * @see java.io.ByteArrayOutputStream#reset()
    082     */
    083    @Override
    084    public void reset() {
    085        resetImpl();
    086    }
    087
    088    @Override
    089    public void writeTo(final OutputStream out) throws IOException {
    090        writeToImpl(out);
    091    }
    092
    093    /**
    094     * Fetches entire contents of an {@code InputStream} and represent same data as result InputStream.
    095     * <p>
    096     * This method is useful where,
    097     * </p>
    098     * <ul>
    099     * <li>Source InputStream is slow.</li>
    100     * <li>It has network resources associated, so we cannot keep it open for long time.</li>
    101     * <li>It has network timeout associated.</li>
    102     * </ul>
    103     * It can be used in favor of {@link #toByteArray()}, since it avoids unnecessary allocation and copy of byte[].<br>
    104     * This method buffers the input internally, so there is no need to use a {@code BufferedInputStream}.
    105     *
    106     * @param input Stream to be fully buffered.
    107     * @return A fully buffered stream.
    108     * @throws IOException if an I/O error occurs.
    109     */
    110    public static InputStream toBufferedInputStream(final InputStream input) throws IOException {
    111        return toBufferedInputStream(input, DEFAULT_SIZE);
    112    }
    113
    114    /**
    115     * Fetches entire contents of an {@code InputStream} and represent same data as result InputStream.
    116     * <p>
    117     * This method is useful where,
    118     * </p>
    119     * <ul>
    120     * <li>Source InputStream is slow.</li>
    121     * <li>It has network resources associated, so we cannot keep it open for long time.</li>
    122     * <li>It has network timeout associated.</li>
    123     * </ul>
    124     * It can be used in favor of {@link #toByteArray()}, since it avoids unnecessary allocation and copy of byte[].<br>
    125     * This method buffers the input internally, so there is no need to use a {@code BufferedInputStream}.
    126     *
    127     * @param input Stream to be fully buffered.
    128     * @param size the initial buffer size
    129     * @return A fully buffered stream.
    130     * @throws IOException if an I/O error occurs.
    131     */
    132    public static InputStream toBufferedInputStream(final InputStream input, final int size) throws IOException {
    133        // It does not matter if a ByteArrayOutputStream is not closed as close() is a no-op
    134        try (final UnsynchronizedByteArrayOutputStream output = new UnsynchronizedByteArrayOutputStream(size)) {
    135            output.write(input);
    136            return output.toInputStream();
    137        }
    138    }
    139
    140    @Override
    141    public InputStream toInputStream() {
    142        return toInputStream(UnsynchronizedByteArrayInputStream::new);
    143    }
    144
    145    @Override
    146    public byte[] toByteArray() {
    147        return toByteArrayImpl();
    148    }
    149}