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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  import org.codehaus.groovy.antlr.AntlrParserPluginFactory;
21  
22  /***
23   * A factory of parser plugin instances
24   *
25   * @version $Revision: 1.8 $
26   */
27  public abstract class ParserPluginFactory {
28      public static ParserPluginFactory newInstance(boolean useNewParser) {
29          if (useNewParser) {
30              Class type = null;
31              String name = "org.codehaus.groovy.antlr.AntlrParserPluginFactory";
32              try {
33                  type = Class.forName(name);
34              }
35              catch (ClassNotFoundException e) {
36                  try {
37                      type = ParserPluginFactory.class.getClassLoader().loadClass(name);
38                  }
39                  catch (ClassNotFoundException e1) {
40                      ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
41                      if (contextClassLoader != null) {
42                          try {
43                              type = contextClassLoader.loadClass(name);
44                          }
45                          catch (ClassNotFoundException e2) {
46                              // ignore
47                          }
48                      }
49                  }
50              }
51  
52              if (type != null) {
53                  try {
54                      return (ParserPluginFactory) type.newInstance();
55                  }
56                  catch (Exception e) {
57                      throw new RuntimeException("Could not create AntlrParserPluginFactory: " + e, e);
58                  }
59              }
60              // can't find Antlr parser, so lets use the Classic one
61          }
62          return new AntlrParserPluginFactory();
63      }
64  
65      public abstract ParserPlugin createParserPlugin();
66  }