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Java > Open Source Codes > com > micronova > util > Template


1 /*
2
3 Copyright 2003-2007 MicroNova (R)
4 All rights reserved.
5
6 Redistribution and use in source and binary forms, with or
7 without modification, are permitted provided that the following
8 conditions are met:
9
10     * Redistributions of source code must retain the above copyright
11     notice, this list of conditions and the following disclaimer.
12
13     * Redistributions in binary form must reproduce the above copyright
14     notice, this list of conditions and the following disclaimer in the
15     documentation and/or other materials provided with the distribution.
16
17     * Neither the name of MicroNova nor the names of its contributors
18     may be used to endorse or promote products derived from this
19     software without specific prior written permission.
20
21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 POSSIBILITY OF SUCH DAMAGE.
32
33 */

34
35
36 package com.micronova.util;
37
38 import java.util.regex.*;
39 import java.util.*;
40
41 /** Recursive template evaluator */
42
43 public class Template
44 {
45     /** Escapes '$' in replacement to avoid group substitution */
46
47     public static String JavaDoc escapeGroup(String JavaDoc x)
48     {
49         StringBuffer JavaDoc in = new StringBuffer JavaDoc(x);
50         StringBuffer JavaDoc out = new StringBuffer JavaDoc();
51
52         boolean isEscaped = false;
53
54         for (int i = 0; i < in.length(); i ++)
55         {
56             char c = in.charAt(i);
57
58             if (c == '$')
59             {
60                 out.append("\\$");
61             }
62             else if (c == '\\')
63             {
64                 out.append("\\\\");
65             }
66             else
67             {
68                 out.append(c);
69             }
70         }
71
72         return out.toString();
73     }
74
75     /** Renders a Template */
76
77     public static Object JavaDoc render(String JavaDoc template, Pattern pattern, int groupIndex, ObjectSource objectSource, Object JavaDoc objectSourceClient, boolean isRecursive, boolean allowGroup) throws Exception JavaDoc
78     {
79         int templateLength = template.length();
80
81         StringBuffer JavaDoc output = new StringBuffer JavaDoc();
82
83         Matcher matcher = pattern.matcher(template);
84
85         while (matcher.find())
86         {
87             String JavaDoc group = matcher.group(groupIndex);
88
89             Object JavaDoc replacement = objectSource.getObject(objectSourceClient, group);
90
91             if (replacement != null)
92             {
93                 if (isRecursive)
94                 {
95                     replacement = render(replacement.toString(), pattern, groupIndex, objectSource, objectSourceClient, isRecursive, allowGroup);
96                 }
97             }
98
99             // full match returns object as-is
100

101             if ((matcher.start() == 0) && (matcher.end() == templateLength))
102             {
103                 return replacement;
104             }
105
106             if (replacement != null)
107             {
108                 if (!allowGroup)
109                 {
110                     replacement = escapeGroup(replacement.toString());
111                 }
112             }
113             else
114             {
115                 replacement = "";
116             }
117
118             matcher.appendReplacement(output, (String JavaDoc)replacement);
119         }
120
121         matcher.appendTail(output);
122
123         return output.toString();
124     }
125 }
126
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