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/* * @(#)ByteArrayOutputStream.java 1.53 06/06/07 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ 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 * @version 1.53, 06/07/06 * @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]; } /** * Writes the specified byte to this byte array output stream. * * @param b the byte to be written. */ public synchronized void write(int b) { int newcount = count + 1; if (newcount > buf.length) { buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); } buf[count] = (byte)b; count = newcount; } /** * 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) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return; } int newcount = count + len; if (newcount > buf.length) { buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); } System.arraycopy(b, off, buf, count, len); count = newcount; } /** * 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 { } }