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    package org.apache.camel.component.pojo;
018    
019    import org.apache.camel.Consumer;
020    import org.apache.camel.Exchange;
021    import org.apache.camel.Processor;
022    import org.apache.camel.Producer;
023    import org.apache.camel.Component;
024    import org.apache.camel.impl.DefaultEndpoint;
025    import org.apache.camel.impl.DefaultProducer;
026    
027    import java.lang.reflect.InvocationTargetException;
028    
029    /**
030     * Represents a pojo endpoint that uses reflection
031     * to send messages around.
032     *
033     * @version $Revision: 519973 $
034     */
035    public class PojoEndpoint extends DefaultEndpoint<PojoExchange> {
036        private final String pojoName;
037        private Object pojo;
038    
039        public PojoEndpoint(String uri, Component component, String pojoName) {
040            super(uri, component);
041            this.pojoName = pojoName;
042        }
043    
044        public PojoComponent getPojoComponent() {
045            return (PojoComponent) super.getComponent();
046        }
047    
048        public Producer<PojoExchange> createProducer() throws Exception {
049            final Object pojo = getPojo();
050            if (pojo == null) {
051                throw new NoPojoAvailableException(this);
052            }
053    
054            return new DefaultProducer(this) {
055                public void process(Exchange exchange) {
056                    PojoExchange pojoExchange = toExchangeType(exchange);
057                    invoke(pojo, pojoExchange);
058                    exchange.copyFrom(pojoExchange);
059                }
060            };
061        }
062    
063        public Consumer<PojoExchange> createConsumer(Processor processor) throws Exception {
064            throw new Exception("You cannot consume from pojo endpoints.");
065        }
066    
067        /**
068         * This causes us to invoke the endpoint Pojo using reflection.
069         *
070         * @param pojo
071         */
072        public static void invoke(Object pojo, PojoExchange exchange) {
073            PojoInvocation invocation = exchange.getInvocation();
074            try {
075                Object response = invocation.getMethod().invoke(pojo, invocation.getArgs());
076                exchange.getOut().setBody(response);
077            }
078            catch (InvocationTargetException e) {
079                exchange.setException(e.getCause());
080            }
081            catch (RuntimeException e) {
082                throw e;
083            }
084            catch (Throwable e) {
085                throw new RuntimeException(e);
086            }
087        }
088    
089        public PojoExchange createExchange() {
090            return new PojoExchange(getContext());
091        }
092    
093        public boolean isSingleton() {
094            return true;
095        }
096    
097        public Object getPojo() {
098            if (pojo == null) {
099                pojo = lookupService();
100            }
101            return pojo;
102        }
103    
104        public void setPojo(Object pojo) {
105            this.pojo = pojo;
106        }
107    
108        public String getPojoName() {
109            return pojoName;
110        }
111    
112        protected Object lookupService() {
113            return getPojoComponent().getService(getPojoName());
114        }
115    }