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: 45097 $
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            if (LOG.isDebugEnabled()) {
072                LOG.debug(">>>> invoking method for: " + exchange);
073            }
074    
075            Object bean = beanHolder.getBean();
076            exchange.setProperty("org.apache.camel.bean.BeanHolder", beanHolder);
077    
078            Processor processor = getProcessor();
079            BeanInfo beanInfo = beanHolder.getBeanInfo();
080    
081            // do we have a custom adapter for this POJO to a Processor
082            if (processor != null) {
083                processor.process(exchange);
084                return;
085            }
086            Message in = exchange.getIn();
087    
088            if (in.getHeader(MULTI_PARAMETER_ARRAY) == null) {
089                in.setHeader(MULTI_PARAMETER_ARRAY, isMultiParameterArray());
090            }
091    
092            BeanInvocation beanInvoke = in.getBody(BeanInvocation.class);
093            if (beanInvoke != null) {
094                beanInvoke.invoke(bean, exchange);
095                return;
096            }
097    
098            boolean isExplicitMethod = false;
099            String prevMethod = null;
100            MethodInvocation invocation;
101            if (methodObject != null) {
102                invocation = beanInfo.createInvocation(methodObject, bean, exchange);
103            } else {
104                // we just override the bean's invocation method name here
105                if (ObjectHelper.isNotNullAndNonEmpty(method)) {
106                    prevMethod = in.getHeader(METHOD_NAME, String.class);
107                    in.setHeader(METHOD_NAME, method);
108                    isExplicitMethod = true;
109                }
110                invocation = beanInfo.createInvocation(bean, exchange);
111            }
112            if (invocation == null) {
113                throw new IllegalStateException("No method invocation could be created, "
114                                                + "no maching method could be found on: " + bean);
115            }
116            try {
117                Object value = invocation.proceed();
118                if (value != null) {
119                    if (exchange.getPattern().isOutCapable()) {
120                        // force out creating if not already created (as its lazy)
121                        if (LOG.isDebugEnabled()) {
122                            LOG.debug("Setting bean invocation value on OUT message: " + value);
123                        }
124                        exchange.getOut(true).setBody(value);
125                    } else {
126                        // if not out then set it on the in
127                        if (LOG.isDebugEnabled()) {
128                            LOG.debug("Setting bean invocation value on IN message: " + value);
129                        }
130                        exchange.getIn().setBody(value);
131                    }
132                }
133            } catch (InvocationTargetException e) {
134                // lets unwrap the exception
135                Throwable cause = e.getCause();
136                if (cause instanceof Exception) {
137                    throw (Exception) cause;
138                } else {
139                    // do not handle errors!
140                    throw e;
141                }
142            } catch (Exception e) {
143                throw e;
144            } catch (Throwable throwable) {
145                throw new Exception(throwable);
146            } finally {
147                if (isExplicitMethod) {
148                    in.setHeader(METHOD_NAME, prevMethod);
149                }
150            }
151        }
152    
153        protected Processor getProcessor() {
154            return beanHolder.getProcessor();
155        }
156    
157        // Properties
158        // -----------------------------------------------------------------------
159    
160        public Method getMethodObject() {
161            return methodObject;
162        }
163    
164        public void setMethodObject(Method methodObject) {
165            this.methodObject = methodObject;
166        }
167    
168        public String getMethod() {
169            return method;
170        }
171    
172        public boolean isMultiParameterArray() {
173            return multiParameterArray;
174        }
175    
176        public void setMultiParameterArray(boolean mpArray) {
177            multiParameterArray = mpArray;
178        }
179    
180        /**
181         * Sets the method name to use
182         */
183        public void setMethod(String method) {
184            this.method = method;
185        }
186    
187        /**
188         * Kept around for backwards compatibility, please use {@link #setMethod(String)}
189         * in future instead.
190         *
191         * @deprecated use {@link #setMethod(String)}. Will be removed in Camel 2.0.
192         */
193        @Deprecated
194        public void setMethodName(String method) {
195            setMethod(method);
196        }
197    
198        // Implementation methods
199        //-------------------------------------------------------------------------
200        protected void doStart() throws Exception {
201            ServiceHelper.startService(getProcessor());
202        }
203    
204        protected void doStop() throws Exception {
205            ServiceHelper.stopService(getProcessor());
206        }
207    }