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1   /***
2    *
3    * Copyright 2004 James Strachan
4    *
5    * Licensed under the Apache License, Version 2.0 (the "License");
6    * you may not use this file except in compliance with the License.
7    * 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   **/
18  package org.codehaus.groovy.control;
19  
20  
21  /***
22   * A factory of parser plugin instances
23   *
24   * @version $Revision: 1.7 $
25   */
26  public abstract class ParserPluginFactory {
27      public static ParserPluginFactory newInstance(boolean useNewParser) {
28          if (useNewParser) {
29              Class type = null;
30              String name = "org.codehaus.groovy.antlr.AntlrParserPluginFactory";
31              try {
32                  type = Class.forName(name);
33              }
34              catch (ClassNotFoundException e) {
35                  try {
36                      type = ParserPluginFactory.class.getClassLoader().loadClass(name);
37                  }
38                  catch (ClassNotFoundException e1) {
39                      ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
40                      if (contextClassLoader != null) {
41                          try {
42                              type = contextClassLoader.loadClass(name);
43                          }
44                          catch (ClassNotFoundException e2) {
45                              // ignore
46                          }
47                      }
48                  }
49              }
50  
51              if (type != null) {
52                  try {
53                      return (ParserPluginFactory) type.newInstance();
54                  }
55                  catch (Exception e) {
56                      throw new RuntimeException("Could not create AntlrParserPluginFactory: " + e, e);
57                  }
58              }
59              // can't find Antlr parser, so lets use the Classic one
60          }
61          return new ClassicParserPluginFactory();
62      }
63  
64      public abstract ParserPlugin createParserPlugin();
65  }