1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219
/* * @(#)StringWriter.java 1.26 05/11/17 * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package java.io; /** * A character stream that collects its output in a string buffer, which can * then be used to construct a string. * <p> * Closing a <tt>StringWriter</tt> has no effect. The methods in this class * can be called after the stream has been closed without generating an * <tt>IOException</tt>. * * @version 1.26, 05/11/17 * @author Mark Reinhold * @since JDK1.1 */ public class StringWriter extends Writer { private StringBuffer buf; /** * Create a new string writer using the default initial string-buffer * size. */ public StringWriter() { buf = new StringBuffer(); lock = buf; } /** * Create a new string writer using the specified initial string-buffer * size. * * @param initialSize * The number of <tt>char</tt> values that will fit into this buffer * before it is automatically expanded * * @throws IllegalArgumentException * If <tt>initialSize</tt> is negative */ public StringWriter(int initialSize) { if (initialSize < 0) { throw new IllegalArgumentException("Negative buffer size"); } buf = new StringBuffer(initialSize); lock = buf; } /** * Write a single character. */ public void write(int c) { buf.append((char) c); } /** * Write a portion of an array of characters. * * @param cbuf Array of characters * @param off Offset from which to start writing characters * @param len Number of characters to write */ public void write(char cbuf[], int off, int len) { if ((off < 0) || (off > cbuf.length) || (len < 0) || ((off + len) > cbuf.length) || ((off + len) < 0)) { throw new IndexOutOfBoundsException(); } else if (len == 0) { return; } buf.append(cbuf, off, len); } /** * Write a string. */ public void write(String str) { buf.append(str); } /** * Write a portion of a string. * * @param str String to be written * @param off Offset from which to start writing characters * @param len Number of characters to write */ public void write(String str, int off, int len) { buf.append(str.substring(off, off + len)); } /** * Appends the specified character sequence to this writer. * * <p> An invocation of this method of the form <tt>out.append(csq)</tt> * behaves in exactly the same way as the invocation * * <pre> * out.write(csq.toString()) </pre> * * <p> Depending on the specification of <tt>toString</tt> for the * character sequence <tt>csq</tt>, the entire sequence may not be * appended. For instance, invoking the <tt>toString</tt> method of a * character buffer will return a subsequence whose content depends upon * the buffer's position and limit. * * @param csq * The character sequence to append. If <tt>csq</tt> is * <tt>null</tt>, then the four characters <tt>"null"</tt> are * appended to this writer. * * @return This writer * * @since 1.5 */ public StringWriter append(CharSequence csq) { if (csq == null) write("null"); else write(csq.toString()); return this; } /** * Appends a subsequence of the specified character sequence to this writer. * * <p> An invocation of this method of the form <tt>out.append(csq, start, * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in * exactly the same way as the invocation * * <pre> * out.write(csq.subSequence(start, end).toString()) </pre> * * @param csq * The character sequence from which a subsequence will be * appended. If <tt>csq</tt> is <tt>null</tt>, then characters * will be appended as if <tt>csq</tt> contained the four * characters <tt>"null"</tt>. * * @param start * The index of the first character in the subsequence * * @param end * The index of the character following the last character in the * subsequence * * @return This writer * * @throws IndexOutOfBoundsException * If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt> * is greater than <tt>end</tt>, or <tt>end</tt> is greater than * <tt>csq.length()</tt> * * @since 1.5 */ public StringWriter append(CharSequence csq, int start, int end) { CharSequence cs = (csq == null ? "null" : csq); write(cs.subSequence(start, end).toString()); return this; } /** * Appends the specified character to this writer. * * <p> An invocation of this method of the form <tt>out.append(c)</tt> * behaves in exactly the same way as the invocation * * <pre> * out.write(c) </pre> * * @param c * The 16-bit character to append * * @return This writer * * @since 1.5 */ public StringWriter append(char c) { write(c); return this; } /** * Return the buffer's current value as a string. */ public String toString() { return buf.toString(); } /** * Return the string buffer itself. * * @return StringBuffer holding the current buffer value. */ public StringBuffer getBuffer() { return buf; } /** * Flush the stream. */ public void flush() { } /** * Closing a <tt>StringWriter</tt> has no effect. The methods in this * class can be called after the stream has been closed without generating * an <tt>IOException</tt>. */ public void close() throws IOException { } }