J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2004 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.io; |
| 27 | |
| 28 | |
| 29 | /** |
| 30 | * A character stream that collects its output in a string buffer, which can |
| 31 | * then be used to construct a string. |
| 32 | * <p> |
| 33 | * Closing a <tt>StringWriter</tt> has no effect. The methods in this class |
| 34 | * can be called after the stream has been closed without generating an |
| 35 | * <tt>IOException</tt>. |
| 36 | * |
| 37 | * @author Mark Reinhold |
| 38 | * @since JDK1.1 |
| 39 | */ |
| 40 | |
| 41 | public class StringWriter extends Writer { |
| 42 | |
| 43 | private StringBuffer buf; |
| 44 | |
| 45 | /** |
| 46 | * Create a new string writer using the default initial string-buffer |
| 47 | * size. |
| 48 | */ |
| 49 | public StringWriter() { |
| 50 | buf = new StringBuffer(); |
| 51 | lock = buf; |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * Create a new string writer using the specified initial string-buffer |
| 56 | * size. |
| 57 | * |
| 58 | * @param initialSize |
| 59 | * The number of <tt>char</tt> values that will fit into this buffer |
| 60 | * before it is automatically expanded |
| 61 | * |
| 62 | * @throws IllegalArgumentException |
| 63 | * If <tt>initialSize</tt> is negative |
| 64 | */ |
| 65 | public StringWriter(int initialSize) { |
| 66 | if (initialSize < 0) { |
| 67 | throw new IllegalArgumentException("Negative buffer size"); |
| 68 | } |
| 69 | buf = new StringBuffer(initialSize); |
| 70 | lock = buf; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Write a single character. |
| 75 | */ |
| 76 | public void write(int c) { |
| 77 | buf.append((char) c); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Write a portion of an array of characters. |
| 82 | * |
| 83 | * @param cbuf Array of characters |
| 84 | * @param off Offset from which to start writing characters |
| 85 | * @param len Number of characters to write |
| 86 | */ |
| 87 | public void write(char cbuf[], int off, int len) { |
| 88 | if ((off < 0) || (off > cbuf.length) || (len < 0) || |
| 89 | ((off + len) > cbuf.length) || ((off + len) < 0)) { |
| 90 | throw new IndexOutOfBoundsException(); |
| 91 | } else if (len == 0) { |
| 92 | return; |
| 93 | } |
| 94 | buf.append(cbuf, off, len); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Write a string. |
| 99 | */ |
| 100 | public void write(String str) { |
| 101 | buf.append(str); |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Write a portion of a string. |
| 106 | * |
| 107 | * @param str String to be written |
| 108 | * @param off Offset from which to start writing characters |
| 109 | * @param len Number of characters to write |
| 110 | */ |
| 111 | public void write(String str, int off, int len) { |
| 112 | buf.append(str.substring(off, off + len)); |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * Appends the specified character sequence to this writer. |
| 117 | * |
| 118 | * <p> An invocation of this method of the form <tt>out.append(csq)</tt> |
| 119 | * behaves in exactly the same way as the invocation |
| 120 | * |
| 121 | * <pre> |
| 122 | * out.write(csq.toString()) </pre> |
| 123 | * |
| 124 | * <p> Depending on the specification of <tt>toString</tt> for the |
| 125 | * character sequence <tt>csq</tt>, the entire sequence may not be |
| 126 | * appended. For instance, invoking the <tt>toString</tt> method of a |
| 127 | * character buffer will return a subsequence whose content depends upon |
| 128 | * the buffer's position and limit. |
| 129 | * |
| 130 | * @param csq |
| 131 | * The character sequence to append. If <tt>csq</tt> is |
| 132 | * <tt>null</tt>, then the four characters <tt>"null"</tt> are |
| 133 | * appended to this writer. |
| 134 | * |
| 135 | * @return This writer |
| 136 | * |
| 137 | * @since 1.5 |
| 138 | */ |
| 139 | public StringWriter append(CharSequence csq) { |
| 140 | if (csq == null) |
| 141 | write("null"); |
| 142 | else |
| 143 | write(csq.toString()); |
| 144 | return this; |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Appends a subsequence of the specified character sequence to this writer. |
| 149 | * |
| 150 | * <p> An invocation of this method of the form <tt>out.append(csq, start, |
| 151 | * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in |
| 152 | * exactly the same way as the invocation |
| 153 | * |
| 154 | * <pre> |
| 155 | * out.write(csq.subSequence(start, end).toString()) </pre> |
| 156 | * |
| 157 | * @param csq |
| 158 | * The character sequence from which a subsequence will be |
| 159 | * appended. If <tt>csq</tt> is <tt>null</tt>, then characters |
| 160 | * will be appended as if <tt>csq</tt> contained the four |
| 161 | * characters <tt>"null"</tt>. |
| 162 | * |
| 163 | * @param start |
| 164 | * The index of the first character in the subsequence |
| 165 | * |
| 166 | * @param end |
| 167 | * The index of the character following the last character in the |
| 168 | * subsequence |
| 169 | * |
| 170 | * @return This writer |
| 171 | * |
| 172 | * @throws IndexOutOfBoundsException |
| 173 | * If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt> |
| 174 | * is greater than <tt>end</tt>, or <tt>end</tt> is greater than |
| 175 | * <tt>csq.length()</tt> |
| 176 | * |
| 177 | * @since 1.5 |
| 178 | */ |
| 179 | public StringWriter append(CharSequence csq, int start, int end) { |
| 180 | CharSequence cs = (csq == null ? "null" : csq); |
| 181 | write(cs.subSequence(start, end).toString()); |
| 182 | return this; |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Appends the specified character to this writer. |
| 187 | * |
| 188 | * <p> An invocation of this method of the form <tt>out.append(c)</tt> |
| 189 | * behaves in exactly the same way as the invocation |
| 190 | * |
| 191 | * <pre> |
| 192 | * out.write(c) </pre> |
| 193 | * |
| 194 | * @param c |
| 195 | * The 16-bit character to append |
| 196 | * |
| 197 | * @return This writer |
| 198 | * |
| 199 | * @since 1.5 |
| 200 | */ |
| 201 | public StringWriter append(char c) { |
| 202 | write(c); |
| 203 | return this; |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Return the buffer's current value as a string. |
| 208 | */ |
| 209 | public String toString() { |
| 210 | return buf.toString(); |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Return the string buffer itself. |
| 215 | * |
| 216 | * @return StringBuffer holding the current buffer value. |
| 217 | */ |
| 218 | public StringBuffer getBuffer() { |
| 219 | return buf; |
| 220 | } |
| 221 | |
| 222 | /** |
| 223 | * Flush the stream. |
| 224 | */ |
| 225 | public void flush() { |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Closing a <tt>StringWriter</tt> has no effect. The methods in this |
| 230 | * class can be called after the stream has been closed without generating |
| 231 | * an <tt>IOException</tt>. |
| 232 | */ |
| 233 | public void close() throws IOException { |
| 234 | } |
| 235 | |
| 236 | } |