ExceptionUtil.java

/*
 *    Copyright 2009-2012 the original author or authors.
 *
 *    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.apache.ibatis.reflection;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.UndeclaredThrowableException;

/**
 * @author Clinton Begin
 */
/**
 * 异常工具
 *
 */
public class ExceptionUtil {

  private ExceptionUtil() {
    // Prevent Instantiation
  }

  public static Throwable unwrapThrowable(Throwable wrapped) {
    Throwable unwrapped = wrapped;
    while (true) {
        //处理2种异常，InvocationTargetException和UndeclaredThrowableException，将它们解包,从而得到真正的异常
      if (unwrapped instanceof InvocationTargetException) {
        unwrapped = ((InvocationTargetException) unwrapped).getTargetException();
      } else if (unwrapped instanceof UndeclaredThrowableException) {
        unwrapped = ((UndeclaredThrowableException) unwrapped).getUndeclaredThrowable();
      } else {
        return unwrapped;
      }
    }
  }

}