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.interceptor;
019    
020    import org.apache.commons.proxy.Invocation;
021    import org.apache.commons.proxy.Interceptor;
022    
023    /**
024     * Decorates another <code>MethodInterceptor</code> by only calling it if the method is accepted by the supplied
025     * <code>MethodFilter</code>.
026     *
027     * @author James Carman
028     * @since 1.0
029     */
030    public class FilteredInterceptor implements Interceptor
031    {
032    //----------------------------------------------------------------------------------------------------------------------
033    // Fields
034    //----------------------------------------------------------------------------------------------------------------------
035    
036        private final Interceptor inner;
037        private final MethodFilter filter;
038    
039    //----------------------------------------------------------------------------------------------------------------------
040    // Constructors
041    //----------------------------------------------------------------------------------------------------------------------
042    
043        public FilteredInterceptor( Interceptor inner, MethodFilter filter )
044        {
045            this.inner = inner;
046            this.filter = filter;
047        }
048    
049    //----------------------------------------------------------------------------------------------------------------------
050    // MethodInterceptor Implementation
051    //----------------------------------------------------------------------------------------------------------------------
052    
053        public Object intercept( Invocation invocation ) throws Throwable
054        {
055            if( filter.accepts( invocation.getMethod() ) )
056            {
057                return inner.intercept( invocation );
058            }
059            else
060            {
061                return invocation.proceed();
062            }
063        }
064    }
065