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1   /* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
2    *
3    * Licensed under the Apache License, Version 2.0 (the "License");
4    * you may not use this file except in compliance with the License.
5    * You may obtain a copy of the License at
6    *
7    *     http://www.apache.org/licenses/LICENSE-2.0
8    *
9    * Unless required by applicable law or agreed to in writing, software
10   * distributed under the License is distributed on an "AS IS" BASIS,
11   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12   * See the License for the specific language governing permissions and
13   * limitations under the License.
14   */
15  
16  package org.acegisecurity.intercept.method;
17  
18  import org.acegisecurity.ConfigAttributeDefinition;
19  
20  import org.aopalliance.intercept.MethodInvocation;
21  
22  import org.apache.commons.logging.Log;
23  import org.apache.commons.logging.LogFactory;
24  
25  import org.aspectj.lang.JoinPoint;
26  import org.aspectj.lang.reflect.CodeSignature;
27  
28  import org.springframework.util.Assert;
29  
30  import java.lang.reflect.Method;
31  
32  
33  /**
34   * Abstract implementation of <Code>MethodDefinitionSource</code>.
35   *
36   * @author Ben Alex
37   * @version $Id: AbstractMethodDefinitionSource.java 1496 2006-05-23 13:38:33Z benalex $
38   */
39  public abstract class AbstractMethodDefinitionSource implements MethodDefinitionSource {
40      //~ Static fields/initializers =====================================================================================
41  
42      private static final Log logger = LogFactory.getLog(AbstractMethodDefinitionSource.class);
43  
44      //~ Methods ========================================================================================================
45  
46      public ConfigAttributeDefinition getAttributes(Object object)
47          throws IllegalArgumentException {
48          Assert.notNull(object, "Object cannot be null");
49  
50          if (object instanceof MethodInvocation) {
51              return this.lookupAttributes(((MethodInvocation) object).getMethod());
52          }
53  
54          if (object instanceof JoinPoint) {
55              JoinPoint jp = (JoinPoint) object;
56              Class targetClazz = jp.getTarget().getClass();
57              String targetMethodName = jp.getStaticPart().getSignature().getName();
58              Class[] types = ((CodeSignature) jp.getStaticPart().getSignature()).getParameterTypes();
59  
60              if (logger.isDebugEnabled()) {
61                  logger.debug("Target Class: " + targetClazz);
62                  logger.debug("Target Method Name: " + targetMethodName);
63  
64                  for (int i = 0; i < types.length; i++) {
65                      if (logger.isDebugEnabled()) {
66                          logger.debug("Target Method Arg #" + i + ": " + types[i]);
67                      }
68                  }
69              }
70  
71              try {
72                  return this.lookupAttributes(targetClazz.getMethod(targetMethodName, types));
73              } catch (NoSuchMethodException nsme) {
74                  throw new IllegalArgumentException("Could not obtain target method from JoinPoint: " + jp);
75              }
76          }
77  
78          throw new IllegalArgumentException("Object must be a MethodInvocation or JoinPoint");
79      }
80  
81      /**
82       * Performs the actual lookup of the relevant <code>ConfigAttributeDefinition</code> for the specified
83       * <code>Method</code> which is subject of the method invocation.<P>Provided so subclasses need only to
84       * provide one basic method to properly interface with the <code>MethodDefinitionSource</code>.</p>
85       *  <p>Returns <code>null</code> if there are no matching attributes for the method.</p>
86       *
87       * @param method the method being invoked for which configuration attributes should be looked up
88       *
89       * @return the <code>ConfigAttributeDefinition</code> that applies to the specified <code>Method</code>
90       */
91      protected abstract ConfigAttributeDefinition lookupAttributes(Method method);
92  
93      public boolean supports(Class clazz) {
94          return (MethodInvocation.class.isAssignableFrom(clazz) || JoinPoint.class.isAssignableFrom(clazz));
95      }
96  }