1 package org.apache.commons.ognl;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.HashMap;
23 import java.util.Map;
24
25 /**
26 * Default class resolution. Uses ClassLoader.loadClass() to look up classes by name. It also looks in the "java.lang"
27 * package
28 * if the class named does not give a package specifier, allowing easier usage of these classes.
29 *
30 * @author Luke Blanshard (blanshlu@netscape.net)
31 * @author Drew Davidson (drew@ognl.org)
32 */
33 public class DefaultClassResolver
34 implements ClassResolver
35 {
36 private final Map<String, Class<?>> classes = new HashMap<String, Class<?>>( 101 );
37
38 /**
39 * Resolves a class for a given className
40 *
41 * @param className The name of the Class
42 * @return The resulting Class object
43 * @throws ClassNotFoundException If the class could not be found
44 */
45 public Class<?> classForName( String className )
46 throws ClassNotFoundException
47 {
48 return classForName( className, null );
49 }
50
51 /**
52 * {@inheritDoc}
53 */
54 public Class<?> classForName( String className, Map<String, Object> unused )
55 throws ClassNotFoundException
56 {
57 Class<?> result = classes.get( className );
58
59 if ( result == null )
60 {
61 ClassLoader classLoader = ClassLoader.getSystemClassLoader();
62 try
63 {
64 result = classLoader.loadClass( className );
65 }
66 catch ( ClassNotFoundException ex )
67 {
68 if ( className.indexOf( '.' ) == -1 )
69 {
70 result = classLoader.loadClass( "java.lang." + className );
71 classes.put( "java.lang." + className, result );
72 }
73 }
74 classes.put( className, result );
75 }
76 return result;
77 }
78 }