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: 13853 $
038     */
039    public class BeanProcessor extends ServiceSupport implements Processor {
040        public static final String METHOD_NAME = "org.apache.camel.MethodName";
041        public static final String MULTI_PARAMETER_ARRAY = "org.apache.camel.MultiParameterArray";
042        private static final transient Log LOG = LogFactory.getLog(BeanProcessor.class);
043    
044        private boolean multiParameterArray;
045        private Method methodObject;
046        private String method;
047        private BeanHolder beanHolder;
048    
049        public BeanProcessor(Object pojo, BeanInfo beanInfo) {
050            this(new ConstantBeanHolder(pojo, beanInfo));
051        }
052    
053        public BeanProcessor(Object pojo, CamelContext camelContext, ParameterMappingStrategy parameterMappingStrategy) {
054            this(pojo, new BeanInfo(camelContext, pojo.getClass(), parameterMappingStrategy));
055        }
056    
057        public BeanProcessor(Object pojo, CamelContext camelContext) {
058            this(pojo, camelContext, BeanInfo.createParameterMappingStrategy(camelContext));
059        }
060    
061        public BeanProcessor(BeanHolder beanHolder) {
062            this.beanHolder = beanHolder;
063        }
064    
065        @Override
066        public String toString() {
067            String description = methodObject != null ? " " + methodObject : "";
068            return "BeanProcessor[" + beanHolder + description + "]";
069        }
070    
071        public void process(Exchange exchange) throws Exception {
072            Object bean = beanHolder.getBean();
073            exchange.setProperty("org.apache.camel.bean.BeanHolder", beanHolder);
074    
075            Processor processor = getProcessor();
076            BeanInfo beanInfo = beanHolder.getBeanInfo();
077    
078            // do we have a custom adapter for this POJO to a Processor
079            if (processor != null) {
080                processor.process(exchange);
081                return;
082            }
083            Message in = exchange.getIn();
084    
085            if (in.getHeader(MULTI_PARAMETER_ARRAY) == null) {
086                in.setHeader(MULTI_PARAMETER_ARRAY, isMultiParameterArray());
087            }
088    
089            try {
090                BeanInvocation beanInvoke = in.getBody(BeanInvocation.class);
091                if (beanInvoke != null) {
092                    beanInvoke.invoke(bean, exchange);
093                    return;
094                }
095            } catch (NoTypeConversionAvailableException ex) {
096                // ignore, body is not a BeanInvocation
097            }
098    
099            boolean isExplicitMethod = false;
100            String prevMethod = null;
101            MethodInvocation invocation;
102            if (methodObject != null) {
103                invocation = beanInfo.createInvocation(methodObject, bean, exchange);
104            } else {
105                // we just override the bean's invocation method name here
106                if (ObjectHelper.isNotNullAndNonEmpty(method)) {
107                    prevMethod = in.getHeader(METHOD_NAME, String.class);
108                    in.setHeader(METHOD_NAME, method);
109                    isExplicitMethod = true;
110                }
111                invocation = beanInfo.createInvocation(bean, exchange);
112            }
113            if (invocation == null) {
114                throw new IllegalStateException(
115                    "No method invocation could be created, no maching method could be found on: " + bean);
116            }
117            Object value = null;
118            try {
119                value = invocation.proceed();            
120            } catch (InvocationTargetException e) {
121                // lets unwrap the exception
122                Throwable throwable = e.getCause();
123                if (throwable instanceof Exception) {
124                    Exception exception = (Exception)throwable;
125                    throw exception;
126                } else {
127                    Error error = (Error)throwable;
128                    throw error;
129                }
130            } finally {
131                if (isExplicitMethod) {
132                    in.setHeader(METHOD_NAME, prevMethod);
133                }
134            }
135            
136            if (value != null) {
137                if (exchange.getPattern().isOutCapable()) {
138                    // force out creating if not already created (as its lazy)
139                    if (LOG.isDebugEnabled()) {
140                        LOG.debug("Setting bean invocation result on the OUT message: " + value);
141                    }
142                    exchange.getOut(true).setBody(value);
143                    // propagate headers
144                    exchange.getOut().getHeaders().putAll(exchange.getIn().getHeaders());
145                } else {
146                    // if not out then set it on the in
147                    if (LOG.isDebugEnabled()) {
148                        LOG.debug("Setting bean invocation result on the IN message: " + value);
149                    }
150                    exchange.getIn().setBody(value);
151                }
152            }
153        }
154    
155        protected Processor getProcessor() {
156            return beanHolder.getProcessor();
157        }
158    
159        // Properties
160        // -----------------------------------------------------------------------
161    
162        public Method getMethodObject() {
163            return methodObject;
164        }
165    
166        public void setMethodObject(Method methodObject) {
167            this.methodObject = methodObject;
168        }
169    
170        public String getMethod() {
171            return method;
172        }
173    
174        public boolean isMultiParameterArray() {
175            return multiParameterArray;
176        }
177    
178        public void setMultiParameterArray(boolean mpArray) {
179            multiParameterArray = mpArray;
180        }
181    
182        /**
183         * Sets the method name to use
184         */
185        public void setMethod(String method) {
186            this.method = method;
187        }
188    
189        /**
190         * Kept around for backwards compatibility, please use {@link #setMethod(String)}
191         * in future instead.
192         *
193         * @deprecated use {@link #setMethod(String)}. Will be removed in Camel 2.0.
194         */
195        @Deprecated
196        public void setMethodName(String method) {
197            setMethod(method);
198        }
199    
200        // Implementation methods
201        //-------------------------------------------------------------------------
202        protected void doStart() throws Exception {
203            ServiceHelper.startService(getProcessor());
204        }
205    
206        protected void doStop() throws Exception {
207            ServiceHelper.stopService(getProcessor());
208        }
209    }