001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.proxy.factory.util;
019
020 import java.lang.reflect.Method;
021 import java.lang.reflect.Modifier;
022 import java.util.Collection;
023 import java.util.HashMap;
024 import java.util.HashSet;
025 import java.util.Iterator;
026 import java.util.Map;
027 import java.util.Set;
028
029 /**
030 * A useful superclass for {@link ProxyClassGenerator} implementations.
031 *
032 * @author James Carman
033 * @since 1.0
034 */
035 public abstract class AbstractProxyClassGenerator implements ProxyClassGenerator
036 {
037 //----------------------------------------------------------------------------------------------------------------------
038 // Static Methods
039 //----------------------------------------------------------------------------------------------------------------------
040
041 /**
042 * Returns all methods that a proxy class must implement from the proxy interfaces. This method makes sure there
043 * are no method signature clashes. For methods with the same signature (name and parameter types), the one
044 * encountered first will be returned in the result. Final methods are also excluded from the result.
045 *
046 * @param proxyClasses the interfaces the proxy class must implement
047 * @return all methods that the proxy class must implement
048 */
049 public static Method[] getImplementationMethods( Class[] proxyClasses )
050 {
051 final Map signatureMethodMap = new HashMap();
052 final Set finalizedSignatures = new HashSet();
053 for( int i = 0; i < proxyClasses.length; i++ )
054 {
055 Class proxyInterface = proxyClasses[i];
056 final Method[] methods = proxyInterface.getMethods();
057 for( int j = 0; j < methods.length; j++ )
058 {
059 final MethodSignature signature = new MethodSignature( methods[j] );
060 if( Modifier.isFinal( methods[j].getModifiers() ) )
061 {
062 finalizedSignatures.add( signature );
063 }
064 else if( !signatureMethodMap.containsKey( signature ) )
065 {
066 signatureMethodMap.put( signature, methods[j] );
067 }
068 }
069 }
070 final Collection resultingMethods = signatureMethodMap.values();
071 for( Iterator i = finalizedSignatures.iterator(); i.hasNext(); )
072 {
073 MethodSignature signature = ( MethodSignature ) i.next();
074 resultingMethods.remove( signatureMethodMap.get( signature ) );
075 }
076 return ( Method[] ) resultingMethods.toArray( new Method[resultingMethods.size()] );
077 }
078 }
079