View Javadoc
1   /**
2    *    Copyright 2009-2015 the original author or authors.
3    *
4    *    Licensed under the Apache License, Version 2.0 (the "License");
5    *    you may not use this file except in compliance with the License.
6    *    You may obtain a copy of the License at
7    *
8    *       http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *    Unless required by applicable law or agreed to in writing, software
11   *    distributed under the License is distributed on an "AS IS" BASIS,
12   *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *    See the License for the specific language governing permissions and
14   *    limitations under the License.
15   */
16  package org.apache.ibatis.parsing;
17  
18  /**
19   * @author Clinton Begin
20   */
21  public class GenericTokenParser {
22  
23    private final String openToken;
24    private final String closeToken;
25    private final TokenHandler handler;
26  
27    public GenericTokenParser(String openToken, String closeToken, TokenHandler handler) {
28      this.openToken = openToken;
29      this.closeToken = closeToken;
30      this.handler = handler;
31    }
32  
33    public String parse(String text) {
34      StringBuilder builder = new StringBuilder();
35      if (text != null && text.length() > 0) {
36        char[] src = text.toCharArray();
37        int offset = 0;
38        int start = text.indexOf(openToken, offset);
39        while (start > -1) {
40          if (start > 0 && src[start - 1] == '\\') {
41            // the variable is escaped. remove the backslash.
42            builder.append(src, offset, start - offset - 1).append(openToken);
43            offset = start + openToken.length();
44          } else {
45            int end = text.indexOf(closeToken, start);
46            if (end == -1) {
47              builder.append(src, offset, src.length - offset);
48              offset = src.length;
49            } else {
50              builder.append(src, offset, start - offset);
51              offset = start + openToken.length();
52              String content = new String(src, offset, end - offset);
53              builder.append(handler.handleToken(content));
54              offset = end + closeToken.length();
55            }
56          }
57          start = text.indexOf(openToken, offset);
58        }
59        if (offset < src.length) {
60          builder.append(src, offset, src.length - offset);
61        }
62      }
63      return builder.toString();
64    }
65  
66  }