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
018package org.apache.commons.proxy2.invoker.recorder;
019
020import java.lang.reflect.Method;
021import java.lang.reflect.Type;
022import java.util.LinkedList;
023import java.util.List;
024
025import org.apache.commons.lang3.reflect.TypeUtils;
026import org.apache.commons.proxy2.Invoker;
027import org.apache.commons.proxy2.ProxyFactory;
028import org.apache.commons.proxy2.ProxyUtils;
029import org.apache.commons.proxy2.invoker.RecordedInvocation;
030
031/**
032 * An {@link InvocationRecorder} records method invocations against its generated proxies.
033 * 
034 */
035public class InvocationRecorder
036{
037    private final ProxyFactory proxyFactory;
038    private final List<RecordedInvocation> recordedInvocations = new LinkedList<RecordedInvocation>();
039
040    /**
041     * Create a new InvocationRecorder instance.
042     * 
043     * @param proxyFactory
044     */
045    public InvocationRecorder(ProxyFactory proxyFactory)
046    {
047        this.proxyFactory = proxyFactory;
048    }
049
050    /**
051     * Get the invocations that have been recorded up to this point. The list is "live" and should not be modified.
052     * 
053     * @return {@link List} of {@link RecordedInvocation}
054     */
055    public List<RecordedInvocation> getRecordedInvocations()
056    {
057        return recordedInvocations;
058    }
059
060    /**
061     * Generate a recording proxy for the specified class.
062     * 
063     * @param <T>
064     * @param type
065     * @return the generated proxy
066     */
067    public <T> T proxy(Class<T> type)
068    {
069        return proxy(type, type);
070    }
071
072    /**
073     * Generate a recording proxy for the specified class, qualified as <code>genericType</code>.
074     * 
075     * @param <T>
076     * @param genericType
077     * @param type
078     * @return the generated proxy
079     */
080    public <T> T proxy(Type genericType, Class<T> type)
081    {
082        if (proxyFactory.canProxy(type))
083        {
084            return proxyFactory.<T> createInvokerProxy(new InvocationRecorderInvoker(genericType), type);
085        }
086        return ProxyUtils.nullValue(type);
087    }
088
089    private final class InvocationRecorderInvoker implements Invoker
090    {
091        /** Serialization version */
092        private static final long serialVersionUID = 1L;
093
094        private final Type targetType;
095
096        private InvocationRecorderInvoker(Type targetType)
097        {
098            this.targetType = targetType;
099        }
100
101        /**
102         * {@inheritDoc}
103         */
104        @Override
105        public Object invoke(Object o, Method method, Object[] args) throws Throwable
106        {
107            recordedInvocations.add(new RecordedInvocation(method, args));
108            final Class<?> returnType = TypeUtils.getRawType(method.getGenericReturnType(), targetType);
109            //what to do if returnType is null?
110            return proxy(method.getGenericReturnType(), returnType);
111        }
112    }
113
114    /**
115     * Reset this {@link InvocationRecorder}.
116     */
117    public void reset()
118    {
119        recordedInvocations.clear();
120    }
121
122}