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1   /*
2    * Copyright 2006 Thierry Guerin
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.exolab.castor.xml.wls8;
17  
18  import java.lang.reflect.InvocationTargetException;
19  import java.lang.reflect.Method;
20  
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  public abstract class WeblogicXercesImplementation {
25      private static final Log LOG = LogFactory.getLog(WeblogicXercesImplementation.class);
26  
27      /**
28       * Returns a Method object that reflects the specified public member method of the class 
29       * or interface represented by <code>aClass</code>.
30       * <br> If either an SecurityException or NoSuchMethodException 
31       * is thrown, calls {@link #handleStaticInitException(Exception)}.
32       * 
33       * @param aClass The class.
34       * @param methodName The name of the method.
35       * @param parameterTypes The list of parameters.
36       * @return The Method object that matches the specified name and parameterTypes.
37       * @see Class#getMethod(java.lang.String, java.lang.Class[])
38       */
39      protected static Method getMethod(Class aClass, String methodName, Class[] parameterTypes) {
40          Method method = null;
41          try {
42              method = aClass.getMethod(methodName, parameterTypes);
43          }
44          catch (SecurityException e) {
45              handleStaticInitException("Error while trying to get the method "
46                      + methodName + " in class " + aClass, e);
47          }
48          catch (NoSuchMethodException e) {
49              handleStaticInitException("Error while trying to get the method "
50                      + methodName + " in class " + aClass, e);
51          }
52          return method;
53      }
54  
55      /**
56       * Invokes a method. Calls {@link Method#invoke(java.lang.Object, java.lang.Object[])}. If either
57       * an IllegalArgumentException, IllegalAccessException or InvocationTargetException is thrown,
58       * calls {@link #handleMethodInvokeException(Exception)}.
59       * 
60       * @param anObject The object instance to invoke the method on.
61       * @param method The method to invoke.
62       * @param params The parameters to pass to the method.
63       * @return If the method completes normally, the value it returns is returned to the caller 
64       * of invoke; if the value has a primitive type, it is first appropriately wrapped in an object.
65       * If the underlying method return type is void, the invocation returns null.
66       * @see Method#invoke(java.lang.Object, java.lang.Object[])
67       */
68      protected Object invoke(Object anObject, Method method, Object[] params) {
69          try {
70              return method.invoke(anObject, params);
71          }
72          catch (IllegalArgumentException e) {
73              handleMethodInvokeException(e);
74          }
75          catch (IllegalAccessException e) {
76              handleMethodInvokeException(e);
77          }
78          catch (InvocationTargetException e) {
79              handleMethodInvokeException(e);
80          }
81          // this code is never reached in theory but is necessary because handleMethodInvokeException
82          // throws a RuntimeException (unchecked).
83          return null;
84      }
85      
86      // exception handling methods
87      public static void handleStaticInitException(Exception e) {
88          handleStaticInitException("Error while intializing class", e);
89      }
90  
91      /**
92       * Throws a Runtime exception with <code>e</code>'s {@link Exception#getMessage() message} as its
93       * detail message. Also logs the exception as an error.
94       * Called if an error occurs during the static initialization of WeblogicXercesSerializer 
95       * & OutputFormat (these classes use reflection to get the Weblogic classes & methods).
96       * 
97       * @param message The Message that will be inserted before <code>e</code>'s 
98       * {@link Exception#getMessage() message} in the RuntimeException's detail message.
99       * @param e The exception that will be "wrapped" in a RuntimeException
100      */
101     public static void handleStaticInitException(String message, Exception e) {
102         LOG.error(message, e);
103         if (e instanceof RuntimeException) // don't wrap the exception
104             throw (RuntimeException) e;
105         throw new RuntimeException(message + ". " + e.getMessage()); // java 1.3, can't wrap using the 1.4 constructor
106     }
107     
108     protected static void handleMethodInvokeException(Exception e) {
109         handleMethodInvokeException("Error while trying to invoke a method", e);
110     }
111 
112     /**
113      * Throws a Runtime exception with <code>e</code>'s {@link Exception#getMessage() message} as its
114      * detail message. Also logs the exception as an error.
115      * 
116      * @param message The Message that will be inserted before <code>e</code>'s 
117      * {@link Exception#getMessage() message} in the RuntimeException's detail message.
118      * @param e The exception that will be "wrapped" in a RuntimeException.
119      */
120     protected static void handleMethodInvokeException(String message, Exception e) {
121         LOG.error(message, e);
122         if (e instanceof RuntimeException) // don't wrap the exception
123             throw (RuntimeException) e;
124         throw new RuntimeException(message + ". " + e.getMessage()); // java 1.3, can't wrap using the 1.4 constructor
125     }
126 }