1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.myfaces.trinidad.util;
20
21 import org.apache.myfaces.trinidad.logging.TrinidadLogger;
22
23 /**
24 * The FastMessageFormat class is a greatly reduced version
25 * of the java.text.MessageFormat class. It's also much faster
26 * and much less expensive to create, which is especially
27 * valuable when it is created and thrown away many times -
28 * a common use case in web applications.
29 * <p>
30 * The only syntax supported by this class is simple index-based
31 * replacement, namely:
32 * <pre>
33 * some{1}text{0}here{2}andthere
34 * </pre>
35 * Unlike MessageFormat, single quotes are NOT used for escaping.
36 * So, the following pattern could be used to include a left bracket:
37 * <pre>
38 * some{text{0}
39 * </pre>
40 * <p>
41 * @version $Name: $ ($Revision: adfrt/faces/adf-faces-api/src/main/java/oracle/adf/view/faces/util/FastMessageFormat.java#0 $) $Date: 10-nov-2005.19:08:37 $
42 */
43 public class FastMessageFormat
44 {
45 /**
46 * Creates a FastMessageFormat based on the given format string.
47 */
48 public FastMessageFormat(String formatString)
49 {
50 if (formatString == null)
51 throw new NullPointerException();
52
53 _formatText = formatString.toCharArray();
54 }
55
56
57 /**
58 * This formatter will only replace patterns of the type "{[0-9]}"
59 * for which there is an associated token.
60 * Any other use of '{}' will be interpreted as literal text.
61 * This aims to have the same behavior as TrFastMessageFormatUtils.format
62 * on the client.
63 * <p>
64 * @param source an array of strings (tokens)
65 */
66 public String format(Object[] source)
67 {
68 int formatLength = _formatText.length;
69 int length = 0;
70 int tokenCount = source.length;
71 for (int i = 0; i < tokenCount; i++)
72 {
73 Object sourceString = source[i];
74 if (sourceString != null)
75 {
76 length += sourceString.toString().length();
77 }
78 }
79
80 // The following buffer size is just an initial estimate. It is legal for
81 // any given pattern, such as {0}, to occur more than once, in which case
82 // the buffer size will expand automatically if need be.
83 StringBuilder buffer = new StringBuilder(length + formatLength);
84
85 int lastStart = 0;
86 for (int i = 0; i < formatLength; i++)
87 {
88 char ch = _formatText[i];
89 if (ch == '{')
90 {
91 // Only check for single digit patterns that have an associated token.
92 if (i + 2 < formatLength && _formatText[i + 2] == '}')
93 {
94 int tokenIndex = _formatText[i + 1] - '0';
95 if (tokenIndex >= 0 && tokenIndex < tokenCount)
96 {
97 buffer.append(_formatText, lastStart, i - lastStart);
98 Object sourceString = source[tokenIndex];
99 if (sourceString != null)
100 buffer.append(sourceString.toString());
101
102 i += 2;
103 lastStart = i + 1;
104 }
105 }
106 }
107 // ELSE: Do nothing. The character will be added in later.
108 }
109
110 buffer.append(_formatText, lastStart, formatLength - lastStart);
111
112 return new String(buffer);
113 }
114
115 private final char[] _formatText;
116 private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(
117 FastMessageFormat.class);
118 }
119
120
121
122