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.bean;
018    
019    import java.lang.reflect.InvocationTargetException;
020    import java.lang.reflect.Method;
021    
022    import org.apache.camel.CamelContext;
023    import org.apache.camel.Exchange;
024    import org.apache.camel.Message;
025    import org.apache.camel.Processor;
026    import org.apache.camel.impl.ServiceSupport;
027    import org.apache.camel.util.ObjectHelper;
028    import org.apache.camel.util.ServiceHelper;
029    import org.apache.commons.logging.Log;
030    import org.apache.commons.logging.LogFactory;
031    
032    /**
033     * A {@link Processor} which converts the inbound exchange to a method
034     * invocation on a POJO
035     *
036     * @version $Revision: 790052 $
037     */
038    public class BeanProcessor extends ServiceSupport implements Processor {
039        private static final transient Log LOG = LogFactory.getLog(BeanProcessor.class);
040    
041        private boolean multiParameterArray;
042        private Method methodObject;
043        private String method;
044        private BeanHolder beanHolder;
045    
046        public BeanProcessor(Object pojo, BeanInfo beanInfo) {
047            this(new ConstantBeanHolder(pojo, beanInfo));
048        }
049    
050        public BeanProcessor(Object pojo, CamelContext camelContext, ParameterMappingStrategy parameterMappingStrategy) {
051            this(pojo, new BeanInfo(camelContext, pojo.getClass(), parameterMappingStrategy));
052        }
053    
054        public BeanProcessor(Object pojo, CamelContext camelContext) {
055            this(pojo, camelContext, BeanInfo.createParameterMappingStrategy(camelContext));
056        }
057    
058        public BeanProcessor(BeanHolder beanHolder) {
059            this.beanHolder = beanHolder;
060        }
061    
062        @Override
063        public String toString() {
064            String description = methodObject != null ? " " + methodObject : "";
065            return "BeanProcessor[" + beanHolder + description + "]";
066        }
067    
068        public void process(Exchange exchange) throws Exception {
069            Object bean = beanHolder.getBean();
070            exchange.setProperty(Exchange.BEAN_HOLDER, beanHolder);
071    
072            Processor processor = getProcessor();
073            BeanInfo beanInfo = beanHolder.getBeanInfo();
074    
075            // do we have a custom adapter for this POJO to a Processor
076            if (processor != null) {
077                processor.process(exchange);
078                return;
079            }
080            Message in = exchange.getIn();
081    
082            if (in.getHeader(Exchange.BEAN_MULTI_PARAMETER_ARRAY) == null) {
083                in.setHeader(Exchange.BEAN_MULTI_PARAMETER_ARRAY, isMultiParameterArray());
084            }
085    
086            BeanInvocation beanInvoke = in.getBody(BeanInvocation.class);
087            if (beanInvoke != null) {
088                beanInvoke.invoke(bean, exchange);
089                return;
090            }
091    
092            boolean isExplicitMethod = false;
093            String prevMethod = null;
094            MethodInvocation invocation;
095            if (methodObject != null) {
096                invocation = beanInfo.createInvocation(methodObject, bean, exchange);
097            } else {
098                // we just override the bean's invocation method name here
099                if (ObjectHelper.isNotEmpty(method)) {
100                    prevMethod = in.getHeader(Exchange.BEAN_METHOD_NAME, String.class);
101                    in.setHeader(Exchange.BEAN_METHOD_NAME, method);
102                    isExplicitMethod = true;
103                }
104                invocation = beanInfo.createInvocation(bean, exchange);
105            }
106            if (invocation == null) {
107                throw new IllegalStateException(
108                    "No method invocation could be created, no maching method could be found on: " + bean);
109            } else {
110                // set method name if not explicit given
111                if (method == null) {
112                    method = invocation.getMethod().getName();
113                }
114            }
115       
116            Object value = null;
117            try {
118                value = invocation.proceed();
119            } catch (InvocationTargetException e) {
120                // lets unwrap the exception
121                Throwable throwable = e.getCause();
122                if (throwable instanceof Exception) {
123                    Exception exception = (Exception)throwable;
124                    throw exception;
125                } else {
126                    Error error = (Error)throwable;
127                    throw error;
128                }
129            } finally {
130                if (isExplicitMethod) {
131                    in.setHeader(Exchange.BEAN_METHOD_NAME, prevMethod);
132                }
133            }
134            
135            if (value != null) {
136                if (exchange.getPattern().isOutCapable()) {
137                    // force out creating if not already created (as its lazy)
138                    if (LOG.isDebugEnabled()) {
139                        LOG.debug("Setting bean invocation result on the OUT message: " + value);
140                    }
141                    exchange.getOut().setBody(value);
142                    // propagate headers
143                    exchange.getOut().getHeaders().putAll(exchange.getIn().getHeaders());
144                } else {
145                    // if not out then set it on the in
146                    if (LOG.isDebugEnabled()) {
147                        LOG.debug("Setting bean invocation result on the IN message: " + value);
148                    }
149                    exchange.getIn().setBody(value);
150                }
151            }
152        }
153    
154        protected Processor getProcessor() {
155            return beanHolder.getProcessor();
156        }
157    
158        // Properties
159        // -----------------------------------------------------------------------
160    
161        public Method getMethodObject() {
162            return methodObject;
163        }
164    
165        public void setMethodObject(Method methodObject) {
166            this.methodObject = methodObject;
167        }
168    
169        public String getMethod() {
170            return method;
171        }
172    
173        public boolean isMultiParameterArray() {
174            return multiParameterArray;
175        }
176    
177        public void setMultiParameterArray(boolean mpArray) {
178            multiParameterArray = mpArray;
179        }
180    
181        /**
182         * Sets the method name to use
183         */
184        public void setMethod(String method) {
185            this.method = method;
186        }
187    
188        // Implementation methods
189        //-------------------------------------------------------------------------
190        protected void doStart() throws Exception {
191            ServiceHelper.startService(getProcessor());
192        }
193    
194        protected void doStop() throws Exception {
195            ServiceHelper.stopService(getProcessor());
196        }
197    }