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: 47154 $
037     */
038    public class BeanProcessor extends ServiceSupport implements Processor {
039        public static final String METHOD_NAME = "org.apache.camel.MethodName";
040        public static final String MULTI_PARAMETER_ARRAY = "org.apache.camel.MultiParameterArray";
041        private static final transient Log LOG = LogFactory.getLog(BeanProcessor.class);
042    
043        private boolean multiParameterArray;
044        private Method methodObject;
045        private String method;
046        private BeanHolder beanHolder;
047    
048        public BeanProcessor(Object pojo, BeanInfo beanInfo) {
049            this(new ConstantBeanHolder(pojo, beanInfo));
050        }
051    
052        public BeanProcessor(Object pojo, CamelContext camelContext, ParameterMappingStrategy parameterMappingStrategy) {
053            this(pojo, new BeanInfo(camelContext, pojo.getClass(), parameterMappingStrategy));
054        }
055    
056        public BeanProcessor(Object pojo, CamelContext camelContext) {
057            this(pojo, camelContext, BeanInfo.createParameterMappingStrategy(camelContext));
058        }
059    
060        public BeanProcessor(BeanHolder beanHolder) {
061            this.beanHolder = beanHolder;
062        }
063    
064        @Override
065        public String toString() {
066            String description = methodObject != null ? " " + methodObject : "";
067            return "BeanProcessor[" + beanHolder + description + "]";
068        }
069    
070        public void process(Exchange exchange) throws Exception {
071            Object bean = beanHolder.getBean();
072            exchange.setProperty("org.apache.camel.bean.BeanHolder", beanHolder);
073    
074            Processor processor = getProcessor();
075            BeanInfo beanInfo = beanHolder.getBeanInfo();
076    
077            // do we have a custom adapter for this POJO to a Processor
078            if (processor != null) {
079                processor.process(exchange);
080                return;
081            }
082            Message in = exchange.getIn();
083    
084            if (in.getHeader(MULTI_PARAMETER_ARRAY) == null) {
085                in.setHeader(MULTI_PARAMETER_ARRAY, isMultiParameterArray());
086            }
087    
088            BeanInvocation beanInvoke = in.getBody(BeanInvocation.class);
089            if (beanInvoke != null) {
090                beanInvoke.invoke(bean, exchange);
091                return;
092            }
093    
094            boolean isExplicitMethod = false;
095            String prevMethod = null;
096            MethodInvocation invocation;
097            if (methodObject != null) {
098                invocation = beanInfo.createInvocation(methodObject, bean, exchange);
099            } else {
100                // we just override the bean's invocation method name here
101                if (ObjectHelper.isNotNullAndNonEmpty(method)) {
102                    prevMethod = in.getHeader(METHOD_NAME, String.class);
103                    in.setHeader(METHOD_NAME, method);
104                    isExplicitMethod = true;
105                }
106                invocation = beanInfo.createInvocation(bean, exchange);
107            }
108            if (invocation == null) {
109                throw new IllegalStateException("No method invocation could be created, "
110                                                + "no maching method could be found on: " + bean);
111            }
112            try {
113                Object value = invocation.proceed();
114                if (value != null) {
115                    if (exchange.getPattern().isOutCapable()) {
116                        // force out creating if not already created (as its lazy)
117                        if (LOG.isDebugEnabled()) {
118                            LOG.debug("Setting bean invocation result on the OUT message: " + value);
119                        }
120                        exchange.getOut(true).setBody(value);
121                    } else {
122                        // if not out then set it on the in
123                        if (LOG.isDebugEnabled()) {
124                            LOG.debug("Setting bean invocation result on the IN message: " + value);
125                        }
126                        exchange.getIn().setBody(value);
127                    }
128                }
129            } catch (InvocationTargetException e) {
130                // lets unwrap the exception
131                Throwable cause = e.getCause();
132                if (cause instanceof Exception) {
133                    throw (Exception) cause;
134                } else {
135                    // do not handle errors!
136                    throw e;
137                }
138            } catch (Exception e) {
139                throw e;
140            } catch (Throwable throwable) {
141                throw new Exception(throwable);
142            } finally {
143                if (isExplicitMethod) {
144                    in.setHeader(METHOD_NAME, prevMethod);
145                }
146            }
147        }
148    
149        protected Processor getProcessor() {
150            return beanHolder.getProcessor();
151        }
152    
153        // Properties
154        // -----------------------------------------------------------------------
155    
156        public Method getMethodObject() {
157            return methodObject;
158        }
159    
160        public void setMethodObject(Method methodObject) {
161            this.methodObject = methodObject;
162        }
163    
164        public String getMethod() {
165            return method;
166        }
167    
168        public boolean isMultiParameterArray() {
169            return multiParameterArray;
170        }
171    
172        public void setMultiParameterArray(boolean mpArray) {
173            multiParameterArray = mpArray;
174        }
175    
176        /**
177         * Sets the method name to use
178         */
179        public void setMethod(String method) {
180            this.method = method;
181        }
182    
183        /**
184         * Kept around for backwards compatibility, please use {@link #setMethod(String)}
185         * in future instead.
186         *
187         * @deprecated use {@link #setMethod(String)}. Will be removed in Camel 2.0.
188         */
189        @Deprecated
190        public void setMethodName(String method) {
191            setMethod(method);
192        }
193    
194        // Implementation methods
195        //-------------------------------------------------------------------------
196        protected void doStart() throws Exception {
197            ServiceHelper.startService(getProcessor());
198        }
199    
200        protected void doStop() throws Exception {
201            ServiceHelper.stopService(getProcessor());
202        }
203    }