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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  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.apache.bcel.util;
19  
20  import java.io.IOException;
21  import java.io.InputStream;
22  import java.util.HashMap;
23  import java.util.Map;
24  
25  import org.apache.bcel.classfile.ClassParser;
26  import org.apache.bcel.classfile.JavaClass;
27  
28  /**
29   * The repository maintains information about which classes have
30   * been loaded.
31   *
32   * It loads its data from the ClassLoader implementation
33   * passed into its constructor.
34   *
35   * @see org.apache.bcel.Repository
36   *
37   * @version $Id: ClassLoaderRepository.html 1018313 2017-09-18 09:03:04Z britter $
38   */
39  public class ClassLoaderRepository implements Repository {
40  
41      private final java.lang.ClassLoader loader;
42      private final Map<String, JavaClass> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
43  
44  
45      public ClassLoaderRepository(final java.lang.ClassLoader loader) {
46          this.loader = loader;
47      }
48  
49  
50      /**
51       * Store a new JavaClass into this Repository.
52       */
53      @Override
54      public void storeClass( final JavaClass clazz ) {
55          loadedClasses.put(clazz.getClassName(), clazz);
56          clazz.setRepository(this);
57      }
58  
59  
60      /**
61       * Remove class from repository
62       */
63      @Override
64      public void removeClass( final JavaClass clazz ) {
65          loadedClasses.remove(clazz.getClassName());
66      }
67  
68  
69      /**
70       * Find an already defined JavaClass.
71       */
72      @Override
73      public JavaClass findClass( final String className ) {
74          return loadedClasses.containsKey(className) ? loadedClasses.get(className) : null;
75      }
76  
77  
78      /**
79       * Lookup a JavaClass object from the Class Name provided.
80       */
81      @Override
82      public JavaClass loadClass(final String className) throws ClassNotFoundException {
83          final String classFile = className.replace('.', '/');
84          JavaClass RC = findClass(className);
85          if (RC != null) {
86              return RC;
87          }
88          try (InputStream is = loader.getResourceAsStream(classFile + ".class")) {
89              if (is == null) {
90                  throw new ClassNotFoundException(className + " not found.");
91              }
92              final ClassParser parser = new ClassParser(is, className);
93              RC = parser.parse();
94              storeClass(RC);
95              return RC;
96          } catch (final IOException e) {
97              throw new ClassNotFoundException(className + " not found: " + e, e);
98          }
99      }
100 
101 
102     @Override
103     public JavaClass loadClass( final Class<?> clazz ) throws ClassNotFoundException {
104         return loadClass(clazz.getName());
105     }
106 
107 
108     /** Clear all entries from cache.
109      */
110     @Override
111     public void clear() {
112         loadedClasses.clear();
113     }
114 
115 
116     /*
117      * @return null
118      */
119     @Override
120     public ClassPath getClassPath() {
121         return null;
122     }
123 }