/*
    * Copyright 2006 Thierry Guerin
    *
    * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
    * in compliance with the License. You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software distributed under the License
   * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
   * or implied. See the License for the specific language governing permissions and limitations under
   * the License.
   */
  package org.exolab.castor.xml.wls8;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  public abstract class WeblogicXercesImplementation {
    private static final Log LOG = LogFactory.getLog(WeblogicXercesImplementation.class);
  
    /**
     * Returns a Method object that reflects the specified public member method of the class or
     * interface represented by <code>aClass</code>. <br>
     * If either an SecurityException or NoSuchMethodException is thrown, calls
     * {@link #handleStaticInitException(Exception)}.
     * 
     * @param aClass The class.
     * @param methodName The name of the method.
     * @param parameterTypes The list of parameters.
     * @return The Method object that matches the specified name and parameterTypes.
     * @see Class#getMethod(java.lang.String, java.lang.Class[])
     */
    protected static Method getMethod(Class aClass, String methodName, Class[] parameterTypes) {
      Method method = null;
      try {
        method = aClass.getMethod(methodName, parameterTypes);
      } catch (SecurityException e) {
        handleStaticInitException(
            "Error while trying to get the method " + methodName + " in class " + aClass, e);
      } catch (NoSuchMethodException e) {
        handleStaticInitException(
            "Error while trying to get the method " + methodName + " in class " + aClass, e);
      }
      return method;
    }
  
    /**
     * Invokes a method. Calls {@link Method#invoke(java.lang.Object, java.lang.Object[])}. If either
     * an IllegalArgumentException, IllegalAccessException or InvocationTargetException is thrown,
     * calls {@link #handleMethodInvokeException(Exception)}.
     * 
     * @param anObject The object instance to invoke the method on.
     * @param method The method to invoke.
     * @param params The parameters to pass to the method.
     * @return If the method completes normally, the value it returns is returned to the caller of
     *         invoke; if the value has a primitive type, it is first appropriately wrapped in an
     *         object. If the underlying method return type is void, the invocation returns null.
     * @see Method#invoke(java.lang.Object, java.lang.Object[])
     */
    protected Object invoke(Object anObject, Method method, Object[] params) {
      try {
        return method.invoke(anObject, params);
      } catch (IllegalArgumentException e) {
        handleMethodInvokeException(e);
      } catch (IllegalAccessException e) {
        handleMethodInvokeException(e);
      } catch (InvocationTargetException e) {
        handleMethodInvokeException(e);
      }
      // this code is never reached in theory but is necessary because handleMethodInvokeException
      // throws a RuntimeException (unchecked).
      return null;
    }
  
    // exception handling methods
    public static void handleStaticInitException(Exception e) {
      handleStaticInitException("Error while intializing class", e);
    }
  
    /**
     * Throws a Runtime exception with <code>e</code>'s {@link Exception#getMessage() message} as its
     * detail message. Also logs the exception as an error. Called if an error occurs during the
     * static initialization of WeblogicXercesSerializer & OutputFormat (these classes use reflection
     * to get the Weblogic classes & methods).
     * 
     * @param message The Message that will be inserted before <code>e</code>'s
     *        {@link Exception#getMessage() message} in the RuntimeException's detail message.
     * @param e The exception that will be "wrapped" in a RuntimeException
     */
    public static void handleStaticInitException(String message, Exception e) {
      LOG.error(message, e);
      if (e instanceof RuntimeException) // don't wrap the exception
        throw (RuntimeException) e;
      throw new RuntimeException(message + ". " + e.getMessage()); // java 1.3, can't wrap using the
                                                                   // 1.4 constructor
   }
 
   protected static void handleMethodInvokeException(Exception e) {
     handleMethodInvokeException("Error while trying to invoke a method", e);
   }
 
   /**
    * Throws a Runtime exception with <code>e</code>'s {@link Exception#getMessage() message} as its
    * detail message. Also logs the exception as an error.
    * 
    * @param message The Message that will be inserted before <code>e</code>'s
    *        {@link Exception#getMessage() message} in the RuntimeException's detail message.
    * @param e The exception that will be "wrapped" in a RuntimeException.
    */
   protected static void handleMethodInvokeException(String message, Exception e) {
     LOG.error(message, e);
     if (e instanceof RuntimeException) // don't wrap the exception
       throw (RuntimeException) e;
     throw new RuntimeException(message + ". " + e.getMessage()); // java 1.3, can't wrap using the
                                                                  // 1.4 constructor
   }
 }