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| 1 | +/* | |
| 2 | + * Copyright (c) 1996, 2005, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | +package java.io; | |
| 27 | + | |
| 28 | +import java.util.Arrays; | |
| 29 | + | |
| 30 | +/** | |
| 31 | + * This class implements a character buffer that can be used as an Writer. | |
| 32 | + * The buffer automatically grows when data is written to the stream. The data | |
| 33 | + * can be retrieved using toCharArray() and toString(). | |
| 34 | + * <P> | |
| 35 | + * Note: Invoking close() on this class has no effect, and methods | |
| 36 | + * of this class can be called after the stream has closed | |
| 37 | + * without generating an IOException. | |
| 38 | + * | |
| 39 | + * @author Herb Jellinek | |
| 40 | + * @since JDK1.1 | |
| 41 | + */ | |
| 42 | +public | |
| 43 | +class CharArrayWriter extends Writer { | |
| 44 | + /** | |
| 45 | + * The buffer where data is stored. | |
| 46 | + */ | |
| 47 | + protected char buf[]; | |
| 48 | + | |
| 49 | + /** | |
| 50 | + * The number of chars in the buffer. | |
| 51 | + */ | |
| 52 | + protected int count; | |
| 53 | + | |
| 54 | + /** | |
| 55 | + * Creates a new CharArrayWriter. | |
| 56 | + */ | |
| 57 | + public CharArrayWriter() { | |
| 58 | + this(32); | |
| 59 | + } | |
| 60 | + | |
| 61 | + /** | |
| 62 | + * Creates a new CharArrayWriter with the specified initial size. | |
| 63 | + * | |
| 64 | + * @param initialSize an int specifying the initial buffer size. | |
| 65 | + * @exception IllegalArgumentException if initialSize is negative | |
| 66 | + */ | |
| 67 | + public CharArrayWriter(int initialSize) { | |
| 68 | + if (initialSize < 0) { | |
| 69 | + throw new IllegalArgumentException("Negative initial size: " | |
| 70 | + + initialSize); | |
| 71 | + } | |
| 72 | + buf = new char[initialSize]; | |
| 73 | + } | |
| 74 | + | |
| 75 | + /** | |
| 76 | + * Writes a character to the buffer. | |
| 77 | + */ | |
| 78 | + public void write(int c) { | |
| 79 | + synchronized (lock) { | |
| 80 | + int newcount = count + 1; | |
| 81 | + if (newcount > buf.length) { | |
| 82 | + buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); | |
| 83 | + } | |
| 84 | + buf[count] = (char)c; | |
| 85 | + count = newcount; | |
| 86 | + } | |
| 87 | + } | |
| 88 | + | |
| 89 | + /** | |
| 90 | + * Writes characters to the buffer. | |
| 91 | + * @param c the data to be written | |
| 92 | + * @param off the start offset in the data | |
| 93 | + * @param len the number of chars that are written | |
| 94 | + */ | |
| 95 | + public void write(char c[], int off, int len) { | |
| 96 | + if ((off < 0) || (off > c.length) || (len < 0) || | |
| 97 | + ((off + len) > c.length) || ((off + len) < 0)) { | |
| 98 | + throw new IndexOutOfBoundsException(); | |
| 99 | + } else if (len == 0) { | |
| 100 | + return; | |
| 101 | + } | |
| 102 | + synchronized (lock) { | |
| 103 | + int newcount = count + len; | |
| 104 | + if (newcount > buf.length) { | |
| 105 | + buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); | |
| 106 | + } | |
| 107 | + System.arraycopy(c, off, buf, count, len); | |
| 108 | + count = newcount; | |
| 109 | + } | |
| 110 | + } | |
| 111 | + | |
| 112 | + /** | |
| 113 | + * Write a portion of a string to the buffer. | |
| 114 | + * @param str String to be written from | |
| 115 | + * @param off Offset from which to start reading characters | |
| 116 | + * @param len Number of characters to be written | |
| 117 | + */ | |
| 118 | + public void write(String str, int off, int len) { | |
| 119 | + synchronized (lock) { | |
| 120 | + int newcount = count + len; | |
| 121 | + if (newcount > buf.length) { | |
| 122 | + buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount)); | |
| 123 | + } | |
| 124 | + str.getChars(off, off + len, buf, count); | |
| 125 | + count = newcount; | |
| 126 | + } | |
| 127 | + } | |
| 128 | + | |
| 129 | + /** | |
| 130 | + * Writes the contents of the buffer to another character stream. | |
| 131 | + * | |
| 132 | + * @param out the output stream to write to | |
| 133 | + * @throws IOException If an I/O error occurs. | |
| 134 | + */ | |
| 135 | + public void writeTo(Writer out) throws IOException { | |
| 136 | + synchronized (lock) { | |
| 137 | + out.write(buf, 0, count); | |
| 138 | + } | |
| 139 | + } | |
| 140 | + | |
| 141 | + /** | |
| 142 | + * Appends the specified character sequence to this writer. | |
| 143 | + * | |
| 144 | + * <p> An invocation of this method of the form <tt>out.append(csq)</tt> | |
| 145 | + * behaves in exactly the same way as the invocation | |
| 146 | + * | |
| 147 | + * <pre> | |
| 148 | + * out.write(csq.toString()) </pre> | |
| 149 | + * | |
| 150 | + * <p> Depending on the specification of <tt>toString</tt> for the | |
| 151 | + * character sequence <tt>csq</tt>, the entire sequence may not be | |
| 152 | + * appended. For instance, invoking the <tt>toString</tt> method of a | |
| 153 | + * character buffer will return a subsequence whose content depends upon | |
| 154 | + * the buffer's position and limit. | |
| 155 | + * | |
| 156 | + * @param csq | |
| 157 | + * The character sequence to append. If <tt>csq</tt> is | |
| 158 | + * <tt>null</tt>, then the four characters <tt>"null"</tt> are | |
| 159 | + * appended to this writer. | |
| 160 | + * | |
| 161 | + * @return This writer | |
| 162 | + * | |
| 163 | + * @since 1.5 | |
| 164 | + */ | |
| 165 | + public CharArrayWriter append(CharSequence csq) { | |
| 166 | + String s = (csq == null ? "null" : csq.toString()); | |
| 167 | + write(s, 0, s.length()); | |
| 168 | + return this; | |
| 169 | + } | |
| 170 | + | |
| 171 | + /** | |
| 172 | + * Appends a subsequence of the specified character sequence to this writer. | |
| 173 | + * | |
| 174 | + * <p> An invocation of this method of the form <tt>out.append(csq, start, | |
| 175 | + * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in | |
| 176 | + * exactly the same way as the invocation | |
| 177 | + * | |
| 178 | + * <pre> | |
| 179 | + * out.write(csq.subSequence(start, end).toString()) </pre> | |
| 180 | + * | |
| 181 | + * @param csq | |
| 182 | + * The character sequence from which a subsequence will be | |
| 183 | + * appended. If <tt>csq</tt> is <tt>null</tt>, then characters | |
| 184 | + * will be appended as if <tt>csq</tt> contained the four | |
| 185 | + * characters <tt>"null"</tt>. | |
| 186 | + * | |
| 187 | + * @param start | |
| 188 | + * The index of the first character in the subsequence | |
| 189 | + * | |
| 190 | + * @param end | |
| 191 | + * The index of the character following the last character in the | |
| 192 | + * subsequence | |
| 193 | + * | |
| 194 | + * @return This writer | |
| 195 | + * | |
| 196 | + * @throws IndexOutOfBoundsException | |
| 197 | + * If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt> | |
| 198 | + * is greater than <tt>end</tt>, or <tt>end</tt> is greater than | |
| 199 | + * <tt>csq.length()</tt> | |
| 200 | + * | |
| 201 | + * @since 1.5 | |
| 202 | + */ | |
| 203 | + public CharArrayWriter append(CharSequence csq, int start, int end) { | |
| 204 | + String s = (csq == null ? "null" : csq).subSequence(start, end).toString(); | |
| 205 | + write(s, 0, s.length()); | |
| 206 | + return this; | |
| 207 | + } | |
| 208 | + | |
| 209 | + /** | |
| 210 | + * Appends the specified character to this writer. | |
| 211 | + * | |
| 212 | + * <p> An invocation of this method of the form <tt>out.append(c)</tt> | |
| 213 | + * behaves in exactly the same way as the invocation | |
| 214 | + * | |
| 215 | + * <pre> | |
| 216 | + * out.write(c) </pre> | |
| 217 | + * | |
| 218 | + * @param c | |
| 219 | + * The 16-bit character to append | |
| 220 | + * | |
| 221 | + * @return This writer | |
| 222 | + * | |
| 223 | + * @since 1.5 | |
| 224 | + */ | |
| 225 | + public CharArrayWriter append(char c) { | |
| 226 | + write(c); | |
| 227 | + return this; | |
| 228 | + } | |
| 229 | + | |
| 230 | + /** | |
| 231 | + * Resets the buffer so that you can use it again without | |
| 232 | + * throwing away the already allocated buffer. | |
| 233 | + */ | |
| 234 | + public void reset() { | |
| 235 | + count = 0; | |
| 236 | + } | |
| 237 | + | |
| 238 | + /** | |
| 239 | + * Returns a copy of the input data. | |
| 240 | + * | |
| 241 | + * @return an array of chars copied from the input data. | |
| 242 | + */ | |
| 243 | + public char toCharArray()[] { | |
| 244 | + synchronized (lock) { | |
| 245 | + return Arrays.copyOf(buf, count); | |
| 246 | + } | |
| 247 | + } | |
| 248 | + | |
| 249 | + /** | |
| 250 | + * Returns the current size of the buffer. | |
| 251 | + * | |
| 252 | + * @return an int representing the current size of the buffer. | |
| 253 | + */ | |
| 254 | + public int size() { | |
| 255 | + return count; | |
| 256 | + } | |
| 257 | + | |
| 258 | + /** | |
| 259 | + * Converts input data to a string. | |
| 260 | + * @return the string. | |
| 261 | + */ | |
| 262 | + public String toString() { | |
| 263 | + synchronized (lock) { | |
| 264 | + return new String(buf, 0, count); | |
| 265 | + } | |
| 266 | + } | |
| 267 | + | |
| 268 | + /** | |
| 269 | + * Flush the stream. | |
| 270 | + */ | |
| 271 | + public void flush() { } | |
| 272 | + | |
| 273 | + /** | |
| 274 | + * Close the stream. This method does not release the buffer, since its | |
| 275 | + * contents might still be required. Note: Invoking this method in this class | |
| 276 | + * will have no effect. | |
| 277 | + */ | |
| 278 | + public void close() { } | |
| 279 | + | |
| 280 | +} | |