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.commons.proxy.factory.util;
19
20 import java.lang.reflect.Method;
21 import java.lang.reflect.Modifier;
22 import java.util.Collection;
23 import java.util.HashMap;
24 import java.util.HashSet;
25 import java.util.Iterator;
26 import java.util.Map;
27 import java.util.Set;
28
29 /**
30 * A useful superclass for {@link ProxyClassGenerator} implementations.
31 *
32 * @author James Carman
33 * @since 1.0
34 */
35 public abstract class AbstractProxyClassGenerator implements ProxyClassGenerator
36 {
37 //----------------------------------------------------------------------------------------------------------------------
38 // Static Methods
39 //----------------------------------------------------------------------------------------------------------------------
40
41 /**
42 * Returns all methods that a proxy class must implement from the proxy interfaces. This method makes sure there
43 * are no method signature clashes. For methods with the same signature (name and parameter types), the one
44 * encountered first will be returned in the result. Final methods are also excluded from the result.
45 *
46 * @param proxyClasses the interfaces the proxy class must implement
47 * @return all methods that the proxy class must implement
48 */
49 public static Method[] getImplementationMethods( Class[] proxyClasses )
50 {
51 final Map signatureMethodMap = new HashMap();
52 final Set finalizedSignatures = new HashSet();
53 for( int i = 0; i < proxyClasses.length; i++ )
54 {
55 Class proxyInterface = proxyClasses[i];
56 final Method[] methods = proxyInterface.getMethods();
57 for( int j = 0; j < methods.length; j++ )
58 {
59 final MethodSignature signature = new MethodSignature( methods[j] );
60 if( Modifier.isFinal( methods[j].getModifiers() ) )
61 {
62 finalizedSignatures.add( signature );
63 }
64 else if( !signatureMethodMap.containsKey( signature ) )
65 {
66 signatureMethodMap.put( signature, methods[j] );
67 }
68 }
69 }
70 final Collection resultingMethods = signatureMethodMap.values();
71 for( Iterator i = finalizedSignatures.iterator(); i.hasNext(); )
72 {
73 MethodSignature signature = ( MethodSignature ) i.next();
74 resultingMethods.remove( signatureMethodMap.get( signature ) );
75 }
76 return ( Method[] ) resultingMethods.toArray( new Method[resultingMethods.size()] );
77 }
78 }
79