ByteArrayInOutStream.java

/*
 * Kontalk Android client
 * Copyright (C) 2017 Kontalk Devteam <devteam@kontalk.org>

 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.kontalk.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;


/**
 * This class extends the ByteArrayOutputStream by 
 * providing a method that returns a new ByteArrayInputStream
 * which uses the internal byte array buffer. This buffer
 * is not copied, so no additional memory is used.
 * <p>
 * The ByteArrayInputStream can be retrieved using <code>getInputStream()</code>.
 * @author Nick Russler https://github.com/nickrussler/ByteArrayInOutStream/
 */
public class ByteArrayInOutStream extends ByteArrayOutputStream {
    /**
     * Creates a new ByteArrayInOutStream. The buffer capacity is
     * initially 32 bytes, though its size increases if necessary.
     */
    public ByteArrayInOutStream() {
        super();
    }

    /**
     * Creates a new ByteArrayInOutStream, with a buffer capacity of
     * the specified size, in bytes.
     *
     * @param   size   the initial size.
     * @exception  IllegalArgumentException if size is negative.
     */
    public ByteArrayInOutStream(int size) {
        super(size);
    }

    /**
     * Creates a new ByteArrayInputStream that uses the internal byte array buffer
     * of this ByteArrayInOutStream instance as its buffer array. The initial value
     * of pos is set to zero and the initial value of count is the number of bytes
     * that can be read from the byte array. The buffer array is not copied.
     * @return the ByteArrayInputStream instance
     */
    public ByteArrayInputStream getInputStream() {
        // create new ByteArrayInputStream that respects the current count
        return new ByteArrayInputStream(this.buf, 0, this.count);
    }
}