| /* |
| * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.io; |
| |
| import java.util.Arrays; |
| |
| /** |
| * This class implements an output stream in which the data is |
| * written into a byte array. The buffer automatically grows as data |
| * is written to it. |
| * The data can be retrieved using <code>toByteArray()</code> and |
| * <code>toString()</code>. |
| * <p> |
| * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in |
| * this class can be called after the stream has been closed without |
| * generating an <tt>IOException</tt>. |
| * |
| * @author Arthur van Hoff |
| * @since JDK1.0 |
| */ |
| |
| public class ByteArrayOutputStream extends OutputStream { |
| |
| /** |
| * The buffer where data is stored. |
| */ |
| protected byte buf[]; |
| |
| /** |
| * The number of valid bytes in the buffer. |
| */ |
| protected int count; |
| |
| /** |
| * Creates a new byte array output stream. The buffer capacity is |
| * initially 32 bytes, though its size increases if necessary. |
| */ |
| public ByteArrayOutputStream() { |
| this(32); |
| } |
| |
| /** |
| * Creates a new byte array output stream, with a buffer capacity of |
| * the specified size, in bytes. |
| * |
| * @param size the initial size. |
| * @exception IllegalArgumentException if size is negative. |
| */ |
| public ByteArrayOutputStream(int size) { |
| if (size < 0) { |
| throw new IllegalArgumentException("Negative initial size: " |
| + size); |
| } |
| buf = new byte[size]; |
| } |
| |
| /** |
| * Increases the capacity if necessary to ensure that it can hold |
| * at least the number of elements specified by the minimum |
| * capacity argument. |
| * |
| * @param minCapacity the desired minimum capacity |
| * @throws OutOfMemoryError if {@code minCapacity < 0}. This is |
| * interpreted as a request for the unsatisfiably large capacity |
| * {@code (long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE)}. |
| */ |
| private void ensureCapacity(int minCapacity) { |
| // overflow-conscious code |
| if (minCapacity - buf.length > 0) |
| grow(minCapacity); |
| } |
| |
| /** |
| * Increases the capacity to ensure that it can hold at least the |
| * number of elements specified by the minimum capacity argument. |
| * |
| * @param minCapacity the desired minimum capacity |
| */ |
| private void grow(int minCapacity) { |
| // overflow-conscious code |
| int oldCapacity = buf.length; |
| int newCapacity = oldCapacity << 1; |
| if (newCapacity - minCapacity < 0) |
| newCapacity = minCapacity; |
| if (newCapacity < 0) { |
| if (minCapacity < 0) // overflow |
| throw new OutOfMemoryError(); |
| newCapacity = Integer.MAX_VALUE; |
| } |
| buf = Arrays.copyOf(buf, newCapacity); |
| } |
| |
| /** |
| * Writes the specified byte to this byte array output stream. |
| * |
| * @param b the byte to be written. |
| */ |
| public synchronized void write(int b) { |
| ensureCapacity(count + 1); |
| buf[count] = (byte) b; |
| count += 1; |
| } |
| |
| /** |
| * Writes <code>len</code> bytes from the specified byte array |
| * starting at offset <code>off</code> to this byte array output stream. |
| * |
| * @param b the data. |
| * @param off the start offset in the data. |
| * @param len the number of bytes to write. |
| */ |
| public synchronized void write(byte b[], int off, int len) { |
| if ((off < 0) || (off > b.length) || (len < 0) || |
| ((off + len) - b.length > 0)) { |
| throw new IndexOutOfBoundsException(); |
| } |
| ensureCapacity(count + len); |
| System.arraycopy(b, off, buf, count, len); |
| count += len; |
| } |
| |
| /** |
| * Writes the complete contents of this byte array output stream to |
| * the specified output stream argument, as if by calling the output |
| * stream's write method using <code>out.write(buf, 0, count)</code>. |
| * |
| * @param out the output stream to which to write the data. |
| * @exception IOException if an I/O error occurs. |
| */ |
| public synchronized void writeTo(OutputStream out) throws IOException { |
| out.write(buf, 0, count); |
| } |
| |
| /** |
| * Resets the <code>count</code> field of this byte array output |
| * stream to zero, so that all currently accumulated output in the |
| * output stream is discarded. The output stream can be used again, |
| * reusing the already allocated buffer space. |
| * |
| * @see java.io.ByteArrayInputStream#count |
| */ |
| public synchronized void reset() { |
| count = 0; |
| } |
| |
| /** |
| * Creates a newly allocated byte array. Its size is the current |
| * size of this output stream and the valid contents of the buffer |
| * have been copied into it. |
| * |
| * @return the current contents of this output stream, as a byte array. |
| * @see java.io.ByteArrayOutputStream#size() |
| */ |
| public synchronized byte toByteArray()[] { |
| return Arrays.copyOf(buf, count); |
| } |
| |
| /** |
| * Returns the current size of the buffer. |
| * |
| * @return the value of the <code>count</code> field, which is the number |
| * of valid bytes in this output stream. |
| * @see java.io.ByteArrayOutputStream#count |
| */ |
| public synchronized int size() { |
| return count; |
| } |
| |
| /** |
| * Converts the buffer's contents into a string decoding bytes using the |
| * platform's default character set. The length of the new <tt>String</tt> |
| * is a function of the character set, and hence may not be equal to the |
| * size of the buffer. |
| * |
| * <p> This method always replaces malformed-input and unmappable-character |
| * sequences with the default replacement string for the platform's |
| * default character set. The {@linkplain java.nio.charset.CharsetDecoder} |
| * class should be used when more control over the decoding process is |
| * required. |
| * |
| * @return String decoded from the buffer's contents. |
| * @since JDK1.1 |
| */ |
| public synchronized String toString() { |
| return new String(buf, 0, count); |
| } |
| |
| /** |
| * Converts the buffer's contents into a string by decoding the bytes using |
| * the specified {@link java.nio.charset.Charset charsetName}. The length of |
| * the new <tt>String</tt> is a function of the charset, and hence may not be |
| * equal to the length of the byte array. |
| * |
| * <p> This method always replaces malformed-input and unmappable-character |
| * sequences with this charset's default replacement string. The {@link |
| * java.nio.charset.CharsetDecoder} class should be used when more control |
| * over the decoding process is required. |
| * |
| * @param charsetName the name of a supported |
| * {@linkplain java.nio.charset.Charset </code>charset<code>} |
| * @return String decoded from the buffer's contents. |
| * @exception UnsupportedEncodingException |
| * If the named charset is not supported |
| * @since JDK1.1 |
| */ |
| public synchronized String toString(String charsetName) |
| throws UnsupportedEncodingException |
| { |
| return new String(buf, 0, count, charsetName); |
| } |
| |
| /** |
| * Creates a newly allocated string. Its size is the current size of |
| * the output stream and the valid contents of the buffer have been |
| * copied into it. Each character <i>c</i> in the resulting string is |
| * constructed from the corresponding element <i>b</i> in the byte |
| * array such that: |
| * <blockquote><pre> |
| * c == (char)(((hibyte & 0xff) << 8) | (b & 0xff)) |
| * </pre></blockquote> |
| * |
| * @deprecated This method does not properly convert bytes into characters. |
| * As of JDK 1.1, the preferred way to do this is via the |
| * <code>toString(String enc)</code> method, which takes an encoding-name |
| * argument, or the <code>toString()</code> method, which uses the |
| * platform's default character encoding. |
| * |
| * @param hibyte the high byte of each resulting Unicode character. |
| * @return the current contents of the output stream, as a string. |
| * @see java.io.ByteArrayOutputStream#size() |
| * @see java.io.ByteArrayOutputStream#toString(String) |
| * @see java.io.ByteArrayOutputStream#toString() |
| */ |
| @Deprecated |
| public synchronized String toString(int hibyte) { |
| return new String(buf, hibyte, 0, count); |
| } |
| |
| /** |
| * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in |
| * this class can be called after the stream has been closed without |
| * generating an <tt>IOException</tt>. |
| * <p> |
| * |
| */ |
| public void close() throws IOException { |
| } |
| |
| } |
