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1   /*
2    * $Id: AnnotatedEntryPointResolver.java 20140 2010-11-09 22:11:42Z mike.schilling $
3    * --------------------------------------------------------------------------------------
4    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
5    *
6    * The software in this package is published under the terms of the CPAL v1.0
7    * license, a copy of which has been included with this distribution in the
8    * LICENSE.txt file.
9    */
10  package org.mule.impl.model.resolvers;
11  
12  import org.mule.api.MuleEventContext;
13  import org.mule.api.annotations.meta.Evaluator;
14  import org.mule.api.config.MuleProperties;
15  import org.mule.api.lifecycle.InitialisationException;
16  import org.mule.api.model.InvocationResult;
17  import org.mule.api.transformer.Transformer;
18  import org.mule.api.transformer.TransformerException;
19  import org.mule.api.transport.PropertyScope;
20  import org.mule.config.expression.ExpressionAnnotationsHelper;
21  import org.mule.config.i18n.CoreMessages;
22  import org.mule.expression.transformers.ExpressionTransformer;
23  import org.mule.model.resolvers.AbstractEntryPointResolver;
24  import org.mule.transport.NullPayload;
25  import org.mule.util.ClassUtils;
26  import org.mule.util.annotation.AnnotationUtils;
27  
28  import java.lang.reflect.Method;
29  import java.util.Map;
30  
31  import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
32  import edu.emory.mathcs.backport.java.util.concurrent.atomic.AtomicBoolean;
33  
34  import net.sf.cglib.proxy.Enhancer;
35  
36  /**
37   * A Mule {@link org.mule.api.model.EntryPointResolver} implementation that will resolve methods on a service class
38   * that have Mule expression annotations such as {@link org.mule.api.annotations.param.Payload}, {@link org.mule.api.annotations.param.InboundHeaders}
39   * It will transform the received message to match the annotated method arguments. For example -
40   * <code>
41   * public Object doSomething(
42   *         &#64;XPath ("/foo/bar") String bar,
43   *         &#64;Payload Document doc,
44   *         &#64;InboundHeaders("name") String name)
45   *  {
46   *      //do stuff
47   *  }
48   * </code>
49   *
50   * The component method above will be invoked by running the XPath expression on the payload, adding a second parameter as
51   * the payload itself and passing in the header 'name' as the third parameter.
52   *
53   * There are some rules for how components with annotations will be processed -
54   * <ul>
55   * <li>For components with more than one method annotated with Mule expression annotations the method name to call needs
56   * to be set on the incoming message or endpoint using the {@link org.mule.api.config.MuleProperties#MULE_METHOD_PROPERTY} key.</li>
57   * <li>If the component has only one method annotated with Mule expression annotations there is no need to set the method name to invoke</li>
58   * <li>Every parameter on the method needs to be annotated</li>
59   * </ul>
60   *
61   * @see org.mule.api.annotations.param.Payload
62   * @see org.mule.api.annotations.param.InboundHeaders
63   * @see org.mule.api.annotations.param.InboundAttachments
64   * @see org.mule.api.annotations.param.OutboundHeaders
65   * @see org.mule.api.annotations.param.OutboundAttachments
66   * @see org.mule.api.annotations.expressions.Mule
67   *
68   * @since 3.0
69   *
70   */
71  public class AnnotatedEntryPointResolver extends AbstractEntryPointResolver
72  {
73  
74      private AtomicBoolean cacheBuilt = new AtomicBoolean(false);
75  
76  
77      @SuppressWarnings("unchecked")
78      private Map<Method, Transformer> transformerCache = new ConcurrentHashMap();
79  
80      public InvocationResult invoke(Object component, MuleEventContext context) throws Exception
81      {
82          try
83          {
84              initCache(component, context);
85          }
86          catch (Exception e)
87          {
88              InvocationResult result = new InvocationResult(this, InvocationResult.State.NOT_SUPPORTED);
89              result.setErrorMessage(e.toString());
90              return result;
91          }
92  
93          if(methodCache.size()==0)
94          {
95              InvocationResult result = new InvocationResult(this, InvocationResult.State.NOT_SUPPORTED);
96              result.setErrorMessage("Component: " + component + " doesn't have any annotated methods, skipping.");
97              return result;
98          }
99  
100         Object[] payload;
101         Method method = null;
102         //We remove the property here as a workaround to MULE-4769
103         Object tempMethod = context.getMessage().removeProperty(MuleProperties.MULE_METHOD_PROPERTY, PropertyScope.INVOCATION);
104         String methodName = null;
105         if (tempMethod != null && tempMethod instanceof Method)
106         {
107             method = (Method) tempMethod;
108         }
109         else
110         {
111             methodName = (String)tempMethod;
112         }
113 
114         //If a method param is set use that over anything else. This is used by the @Reply Callbacks and where annotations are set
115         //on the method
116         if (methodName != null)
117         {
118             method = getMethodByName(methodName, context);
119             if (method == null)
120             {
121                 InvocationResult result = new InvocationResult(this, InvocationResult.State.NOT_SUPPORTED);
122                 result.setErrorMessage("Method not found: " + methodName + " on object: " + component.getClass() + ". If the component is a proxy there needs to be an interface on the proxy that defines this method");
123                 return result;
124                 //TODO i18n
125             }
126             payload = getPayloadForMethod(method, component, context);
127         }
128         else if (method != null)
129         {
130             payload = getPayloadForMethod(method, component, context);
131         }
132         else if (methodCache.size() == 1)
133         {
134             method = (Method) methodCache.values().iterator().next();
135             payload = getPayloadForMethod(method, component, context);
136         }
137         else
138         {
139             InvocationResult result = new InvocationResult(this, InvocationResult.State.FAILED);
140             result.setErrorMessage("Component: " + component + " has more than one method annotated, which means the target method name needs to be set on the event");
141             return result;
142         }
143         return invokeMethod(component, method,
144                 (method.getParameterTypes().length == 0 ? ClassUtils.NO_ARGS : payload));
145     }
146 
147     protected Object[] getPayloadForMethod(Method method, Object component, MuleEventContext context) throws TransformerException, InitialisationException
148     {
149         Object[] payload = null;
150         Method m = method;
151         //If we are using cglib enhanced service objects, we need to read annotations from the real component class
152         if (Enhancer.isEnhanced(component.getClass()))
153         {
154             try
155             {
156                 m = component.getClass().getSuperclass().getMethod(method.getName(), method.getParameterTypes());
157             }
158             catch (NoSuchMethodException e)
159             {
160                 throw new TransformerException(CoreMessages.createStaticMessage(e.getMessage()), e);
161             }
162         }
163 
164         if (AnnotationUtils.getParamAnnotationsWithMeta(m, Evaluator.class).size() > 0)
165         {
166             payload = getPayloadFromMessageWithAnnotations(m, context);
167         }
168         return payload;
169     }
170 
171     protected Object[] getPayloadFromMessageWithAnnotations(Method method, MuleEventContext context) throws TransformerException, InitialisationException
172     {
173         ExpressionTransformer trans = (ExpressionTransformer) transformerCache.get(method);
174         if (trans == null)
175         {
176             trans = ExpressionAnnotationsHelper.getTransformerForMethodWithAnnotations(method, context.getMuleContext());
177             transformerCache.put(method, trans);
178         }
179 
180         Object o = trans.transform(context.getMessage());
181         if (o instanceof NullPayload)
182         {
183             return new Object[]{null};
184         }
185         else if (o.getClass().isArray())
186         {
187             return (Object[]) o;
188         }
189         else
190         {
191             return new Object[]{o};
192         }
193     }
194 
195     @Override
196     public String toString()
197     {
198         final StringBuffer sb = new StringBuffer();
199         sb.append("AnnotatedEntryPointResolver");
200         sb.append(", acceptVoidMethods=").append(isAcceptVoidMethods());
201         sb.append('}');
202         return sb.toString();
203     }
204 
205 
206     protected void initCache(Object component, MuleEventContext context)
207     {
208         if (!cacheBuilt.get())
209         {
210             synchronized (this)
211             {
212                 try
213                 {
214                     if (!cacheBuilt.get())
215                     {
216                         for (int i = 0; i < component.getClass().getMethods().length; i++)
217                         {
218                             Method method = component.getClass().getMethods()[i];
219                             if (AnnotationUtils.getParamAnnotationsWithMeta(method, Evaluator.class).size() > 0)
220                             {
221                                 this.addMethodByName(method, context);
222                             }
223                         }
224                     }
225                 }
226                 finally
227                 {
228                     cacheBuilt.set(true);
229                 }
230             }
231         }
232     }
233 }