1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.directory.api.util;
18
19
20 import java.io.Writer;
21
22
23 /**
24 * {@link Writer} implementation that outputs to a {@link StringBuilder}.
25 * <p>
26 * <strong>NOTE:</strong> This implementation, as an alternative to
27 * <code>java.io.StringWriter</code>, provides an <i>un-synchronized</i>
28 * (i.e. for use in a single thread) implementation for better performance.
29 * For safe usage with multiple {@link Thread}s then
30 * <code>java.io.StringWriter</code> should be used.
31 *
32 * @version $Id: StringBuilderWriter.java 1415850 2012-11-30 20:51:39Z ggregory $
33 * @since 2.0
34 */
35 public class StringBuilderWriter extends Writer
36 {
37
38 private final StringBuilder builder;
39
40
41 /**
42 * Construct a new {@link StringBuilder} instance with default capacity.
43 */
44 public StringBuilderWriter()
45 {
46 builder = new StringBuilder();
47 }
48
49
50 /**
51 * Construct a new {@link StringBuilder} instance with the specified capacity.
52 *
53 * @param capacity The initial capacity of the underlying {@link StringBuilder}
54 */
55 public StringBuilderWriter( int capacity )
56 {
57 builder = new StringBuilder( capacity );
58 }
59
60
61 /**
62 * Construct a new instance with the specified {@link StringBuilder}.
63 *
64 * @param builder The String builder
65 */
66 public StringBuilderWriter( StringBuilder builder )
67 {
68 this.builder = builder != null ? builder : new StringBuilder();
69 }
70
71
72 /**
73 * Append a single character to this Writer.
74 *
75 * @param value The character to append
76 * @return This writer instance
77 */
78 @Override
79 public Writer append( char value )
80 {
81 builder.append( value );
82
83 return this;
84 }
85
86
87 /**
88 * Append a character sequence to this Writer.
89 *
90 * @param value The character to append
91 * @return This writer instance
92 */
93 @Override
94 public Writer append( CharSequence value )
95 {
96 builder.append( value );
97
98 return this;
99 }
100
101
102 /**
103 * Append a portion of a character sequence to the {@link StringBuilder}.
104 *
105 * @param value The character to append
106 * @param start The index of the first character
107 * @param end The index of the last character + 1
108 * @return This writer instance
109 */
110 @Override
111 public Writer append( CharSequence value, int start, int end )
112 {
113 builder.append( value, start, end );
114
115 return this;
116 }
117
118
119 /**
120 * Closing this writer has no effect.
121 */
122 @Override
123 public void close()
124 {
125 }
126
127
128 /**
129 * Flushing this writer has no effect.
130 */
131 @Override
132 public void flush()
133 {
134 }
135
136
137 /**
138 * Write a String to the {@link StringBuilder}.
139 *
140 * @param value The value to write
141 */
142 @Override
143 public void write( String value )
144 {
145 if ( value != null )
146 {
147 builder.append( value );
148 }
149 }
150
151
152 /**
153 * Write a portion of a character array to the {@link StringBuilder}.
154 *
155 * @param value The value to write
156 * @param offset The index of the first character
157 * @param length The number of characters to write
158 */
159 @Override
160 public void write( char[] value, int offset, int length )
161 {
162 if ( value != null )
163 {
164 builder.append( value, offset, length );
165 }
166 }
167
168
169 /**
170 * Return the underlying builder.
171 *
172 * @return The underlying builder
173 */
174 public StringBuilder getBuilder()
175 {
176 return builder;
177 }
178
179
180 /**
181 * Returns {@link StringBuilder#toString()}.
182 *
183 * @return The contents of the String builder.
184 */
185 @Override
186 public String toString()
187 {
188 return builder.toString();
189 }
190 }