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.NoTypeConversionAvailableException;
026    import org.apache.camel.Processor;
027    import org.apache.camel.impl.ServiceSupport;
028    import org.apache.camel.util.ObjectHelper;
029    import org.apache.camel.util.ServiceHelper;
030    import org.apache.commons.logging.Log;
031    import org.apache.commons.logging.LogFactory;
032    
033    /**
034     * A {@link Processor} which converts the inbound exchange to a method
035     * invocation on a POJO
036     *
037     * @version $Revision: 750349 $
038     */
039    public class BeanProcessor extends ServiceSupport implements Processor {
040        private static final transient Log LOG = LogFactory.getLog(BeanProcessor.class);
041    
042        private boolean multiParameterArray;
043        private Method methodObject;
044        private String method;
045        private BeanHolder beanHolder;
046    
047        public BeanProcessor(Object pojo, BeanInfo beanInfo) {
048            this(new ConstantBeanHolder(pojo, beanInfo));
049        }
050    
051        public BeanProcessor(Object pojo, CamelContext camelContext, ParameterMappingStrategy parameterMappingStrategy) {
052            this(pojo, new BeanInfo(camelContext, pojo.getClass(), parameterMappingStrategy));
053        }
054    
055        public BeanProcessor(Object pojo, CamelContext camelContext) {
056            this(pojo, camelContext, BeanInfo.createParameterMappingStrategy(camelContext));
057        }
058    
059        public BeanProcessor(BeanHolder beanHolder) {
060            this.beanHolder = beanHolder;
061        }
062    
063        @Override
064        public String toString() {
065            String description = methodObject != null ? " " + methodObject : "";
066            return "BeanProcessor[" + beanHolder + description + "]";
067        }
068    
069        public void process(Exchange exchange) throws Exception {
070            Object bean = beanHolder.getBean();
071            exchange.setProperty(Exchange.BEAN_HOLDER, beanHolder);
072    
073            Processor processor = getProcessor();
074            BeanInfo beanInfo = beanHolder.getBeanInfo();
075    
076            // do we have a custom adapter for this POJO to a Processor
077            if (processor != null) {
078                processor.process(exchange);
079                return;
080            }
081            Message in = exchange.getIn();
082    
083            if (in.getHeader(Exchange.BEAN_MULTI_PARAMETER_ARRAY) == null) {
084                in.setHeader(Exchange.BEAN_MULTI_PARAMETER_ARRAY, isMultiParameterArray());
085            }
086    
087            try {
088                BeanInvocation beanInvoke = in.getBody(BeanInvocation.class);
089                if (beanInvoke != null) {
090                    beanInvoke.invoke(bean, exchange);
091                    return;
092                }
093            } catch (NoTypeConversionAvailableException ex) {
094                // ignore, body is not a BeanInvocation
095            }
096    
097            boolean isExplicitMethod = false;
098            String prevMethod = null;
099            MethodInvocation invocation;
100            if (methodObject != null) {
101                invocation = beanInfo.createInvocation(methodObject, bean, exchange);
102            } else {
103                // we just override the bean's invocation method name here
104                if (ObjectHelper.isNotEmpty(method)) {
105                    prevMethod = in.getHeader(Exchange.BEAN_METHOD_NAME, String.class);
106                    in.setHeader(Exchange.BEAN_METHOD_NAME, method);
107                    isExplicitMethod = true;
108                }
109                invocation = beanInfo.createInvocation(bean, exchange);
110            }
111            if (invocation == null) {
112                throw new IllegalStateException(
113                    "No method invocation could be created, no maching method could be found on: " + bean);
114            }
115            try {
116                Object value = invocation.proceed();
117                if (value != null) {
118                    if (exchange.getPattern().isOutCapable()) {
119                        // force out creating if not already created (as its lazy)
120                        if (LOG.isDebugEnabled()) {
121                            LOG.debug("Setting bean invocation result on the OUT message: " + value);
122                        }
123                        exchange.getOut(true).setBody(value);
124                    } else {
125                        // if not out then set it on the in
126                        if (LOG.isDebugEnabled()) {
127                            LOG.debug("Setting bean invocation result on the IN message: " + value);
128                        }
129                        exchange.getIn().setBody(value);
130                    }
131                }
132            } catch (InvocationTargetException e) {
133                // lets unwrap the exception
134                Throwable throwable = e.getCause();
135                if (throwable instanceof Exception) {
136                    Exception exception = (Exception)throwable;
137                    throw exception;
138                } else {
139                    Error error = (Error)throwable;
140                    throw error;
141                }
142            } finally {
143                if (isExplicitMethod) {
144                    in.setHeader(Exchange.BEAN_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        // Implementation methods
184        //-------------------------------------------------------------------------
185        protected void doStart() throws Exception {
186            ServiceHelper.startService(getProcessor());
187        }
188    
189        protected void doStop() throws Exception {
190            ServiceHelper.stopService(getProcessor());
191        }
192    }