001: /*
002: * Copyright 1994-2006 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025:
026: package java.io;
027:
028: import java.util.Arrays;
029:
030: /**
031: * This class implements an output stream in which the data is
032: * written into a byte array. The buffer automatically grows as data
033: * is written to it.
034: * The data can be retrieved using <code>toByteArray()</code> and
035: * <code>toString()</code>.
036: * <p>
037: * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
038: * this class can be called after the stream has been closed without
039: * generating an <tt>IOException</tt>.
040: *
041: * @author Arthur van Hoff
042: * @version 1.59, 05/05/07
043: * @since JDK1.0
044: */
045:
046: public class ByteArrayOutputStream extends OutputStream {
047:
048: /**
049: * The buffer where data is stored.
050: */
051: protected byte buf[];
052:
053: /**
054: * The number of valid bytes in the buffer.
055: */
056: protected int count;
057:
058: /**
059: * Creates a new byte array output stream. The buffer capacity is
060: * initially 32 bytes, though its size increases if necessary.
061: */
062: public ByteArrayOutputStream() {
063: this (32);
064: }
065:
066: /**
067: * Creates a new byte array output stream, with a buffer capacity of
068: * the specified size, in bytes.
069: *
070: * @param size the initial size.
071: * @exception IllegalArgumentException if size is negative.
072: */
073: public ByteArrayOutputStream(int size) {
074: if (size < 0) {
075: throw new IllegalArgumentException(
076: "Negative initial size: " + size);
077: }
078: buf = new byte[size];
079: }
080:
081: /**
082: * Writes the specified byte to this byte array output stream.
083: *
084: * @param b the byte to be written.
085: */
086: public synchronized void write(int b) {
087: int newcount = count + 1;
088: if (newcount > buf.length) {
089: buf = Arrays.copyOf(buf, Math
090: .max(buf.length << 1, newcount));
091: }
092: buf[count] = (byte) b;
093: count = newcount;
094: }
095:
096: /**
097: * Writes <code>len</code> bytes from the specified byte array
098: * starting at offset <code>off</code> to this byte array output stream.
099: *
100: * @param b the data.
101: * @param off the start offset in the data.
102: * @param len the number of bytes to write.
103: */
104: public synchronized void write(byte b[], int off, int len) {
105: if ((off < 0) || (off > b.length) || (len < 0)
106: || ((off + len) > b.length) || ((off + len) < 0)) {
107: throw new IndexOutOfBoundsException();
108: } else if (len == 0) {
109: return;
110: }
111: int newcount = count + len;
112: if (newcount > buf.length) {
113: buf = Arrays.copyOf(buf, Math
114: .max(buf.length << 1, newcount));
115: }
116: System.arraycopy(b, off, buf, count, len);
117: count = newcount;
118: }
119:
120: /**
121: * Writes the complete contents of this byte array output stream to
122: * the specified output stream argument, as if by calling the output
123: * stream's write method using <code>out.write(buf, 0, count)</code>.
124: *
125: * @param out the output stream to which to write the data.
126: * @exception IOException if an I/O error occurs.
127: */
128: public synchronized void writeTo(OutputStream out)
129: throws IOException {
130: out.write(buf, 0, count);
131: }
132:
133: /**
134: * Resets the <code>count</code> field of this byte array output
135: * stream to zero, so that all currently accumulated output in the
136: * output stream is discarded. The output stream can be used again,
137: * reusing the already allocated buffer space.
138: *
139: * @see java.io.ByteArrayInputStream#count
140: */
141: public synchronized void reset() {
142: count = 0;
143: }
144:
145: /**
146: * Creates a newly allocated byte array. Its size is the current
147: * size of this output stream and the valid contents of the buffer
148: * have been copied into it.
149: *
150: * @return the current contents of this output stream, as a byte array.
151: * @see java.io.ByteArrayOutputStream#size()
152: */
153: public synchronized byte toByteArray()[] {
154: return Arrays.copyOf(buf, count);
155: }
156:
157: /**
158: * Returns the current size of the buffer.
159: *
160: * @return the value of the <code>count</code> field, which is the number
161: * of valid bytes in this output stream.
162: * @see java.io.ByteArrayOutputStream#count
163: */
164: public synchronized int size() {
165: return count;
166: }
167:
168: /**
169: * Converts the buffer's contents into a string decoding bytes using the
170: * platform's default character set. The length of the new <tt>String</tt>
171: * is a function of the character set, and hence may not be equal to the
172: * size of the buffer.
173: *
174: * <p> This method always replaces malformed-input and unmappable-character
175: * sequences with the default replacement string for the platform's
176: * default character set. The {@linkplain java.nio.charset.CharsetDecoder}
177: * class should be used when more control over the decoding process is
178: * required.
179: *
180: * @return String decoded from the buffer's contents.
181: * @since JDK1.1
182: */
183: public synchronized String toString() {
184: return new String(buf, 0, count);
185: }
186:
187: /**
188: * Converts the buffer's contents into a string by decoding the bytes using
189: * the specified {@link java.nio.charset.Charset charsetName}. The length of
190: * the new <tt>String</tt> is a function of the charset, and hence may not be
191: * equal to the length of the byte array.
192: *
193: * <p> This method always replaces malformed-input and unmappable-character
194: * sequences with this charset's default replacement string. The {@link
195: * java.nio.charset.CharsetDecoder} class should be used when more control
196: * over the decoding process is required.
197: *
198: * @param charsetName the name of a supported
199: * {@linkplain java.nio.charset.Charset </code>charset<code>}
200: * @return String decoded from the buffer's contents.
201: * @exception UnsupportedEncodingException
202: * If the named charset is not supported
203: * @since JDK1.1
204: */
205: public synchronized String toString(String charsetName)
206: throws UnsupportedEncodingException {
207: return new String(buf, 0, count, charsetName);
208: }
209:
210: /**
211: * Creates a newly allocated string. Its size is the current size of
212: * the output stream and the valid contents of the buffer have been
213: * copied into it. Each character <i>c</i> in the resulting string is
214: * constructed from the corresponding element <i>b</i> in the byte
215: * array such that:
216: * <blockquote><pre>
217: * c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
218: * </pre></blockquote>
219: *
220: * @deprecated This method does not properly convert bytes into characters.
221: * As of JDK 1.1, the preferred way to do this is via the
222: * <code>toString(String enc)</code> method, which takes an encoding-name
223: * argument, or the <code>toString()</code> method, which uses the
224: * platform's default character encoding.
225: *
226: * @param hibyte the high byte of each resulting Unicode character.
227: * @return the current contents of the output stream, as a string.
228: * @see java.io.ByteArrayOutputStream#size()
229: * @see java.io.ByteArrayOutputStream#toString(String)
230: * @see java.io.ByteArrayOutputStream#toString()
231: */
232: @Deprecated
233: public synchronized String toString(int hibyte) {
234: return new String(buf, hibyte, 0, count);
235: }
236:
237: /**
238: * Closing a <tt>ByteArrayOutputStream</tt> has no effect. The methods in
239: * this class can be called after the stream has been closed without
240: * generating an <tt>IOException</tt>.
241: * <p>
242: *
243: */
244: public void close() throws IOException {
245: }
246:
247: }
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