content: /* ========================================================================
   * JCommon : a free general purpose class library for the Java(tm) platform
   * ========================================================================
   *
   * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
   * 
   * Project Info:  http://www.jfree.org/jcommon/index.html
   *
   * This library is free software; you can redistribute it and/or modify it 
   * under the terms of the GNU Lesser General Public License as published by 
   * the Free Software Foundation; either version 2.1 of the License, or 
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but 
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
   * USA.  
   *
   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
   * in the United States and other countries.]
   * 
   * -----------------------
   * StackableException.java
   * -----------------------
   * (C)opyright 2002-2004, by Thomas Morgner and Contributors.
   *
   * Original Author:  Thomas Morgner;
   * Contributor(s):   David Gilbert (for Object Refinery Limited);
   *
   * $Id: StackableException.java,v 1.3 2005/11/14 10:56:55 mungady Exp $
   *
   * Changes
   * -------
   * 06-Dec-2002 : Initial version
   * 10-Dec-2002 : Fixed issues reported by Checkstyle (DG);
   * 29-Apr-2003 : Distilled from the JFreeReport project and moved into JCommon
   *
   */
  
  package org.jfree.util;
  
  import java.io.PrintStream;
  import java.io.PrintWriter;
  
  /**
   * A baseclass for exceptions, which could have parent exceptions. These parent exceptions
   * are raised in a subclass and are now wrapped into a subclass of this Exception.
   * <p>
   * The parents are printed when this exception is printed. This class exists mainly for
   * debugging reasons, as with them it is easier to detect the root cause of an error.
   *
   * <!-- In a perfect world there would be no need for such a class :)-->
   *
   * @author Thomas Morgner
   */
  public abstract class StackableException extends Exception {
  
      /** The parent exception. */
      private Exception parent;
  
      /**
       * Creates a StackableRuntimeException with no message and no parent.
       */
      public StackableException() {
          super();
      }
  
      /**
       * Creates an exception.
       *
       * @param message  the exception message.
       * @param ex  the parent exception.
       */
      public StackableException(final String message, final Exception ex) {
          super(message);
          this.parent = ex;
      }
  
      /**
       * Creates an exception.
       *
       * @param message  the exception message.
       */
      public StackableException(final String message) {
          super(message);
      }
  
      /**
       * Returns the parent exception (possibly null).
       *
       * @return the parent exception.
       */
      public Exception getParent() {
          return this.parent;
      }
  
      /**
       * Prints the stack trace to the specified stream.
       *
       * @param stream  the output stream.
       */
      public void printStackTrace(final PrintStream stream) {
          super.printStackTrace(stream);
          if (getParent() != null) {
              stream.println("ParentException: ");
              getParent().printStackTrace(stream);
          }
      }
  
      /**
       * Prints the stack trace to the specified writer.
       *
       * @param writer  the writer.
       */
      public void printStackTrace(final PrintWriter writer) {
          super.printStackTrace(writer);
          if (getParent() != null) {
              writer.println("ParentException: ");
              getParent().printStackTrace(writer);
          }
      }
  
      /**
       * Prints this <code>Throwable</code> and its backtrace to the
       * standard error stream. This method prints a stack trace for this
       * <code>Throwable</code> object on the error output stream that is
       * the value of the field <code>System.err</code>. The first line of
       * output contains the result of the {@link #toString()} method for
       * this object. Remaining lines represent data previously recorded by
       * the method {@link #fillInStackTrace()}. The format of this
       * information depends on the implementation, but the following
       * example may be regarded as typical:
       * <blockquote><pre>
       * java.lang.NullPointerException
       *         at MyClass.mash(MyClass.java:9)
       *         at MyClass.crunch(MyClass.java:6)
       *         at MyClass.main(MyClass.java:3)
       * </pre></blockquote>
       * This example was produced by running the program:
       * <blockquote><pre>
       *
       * class MyClass {
       *
       *     public static void main(String[] argv) {
       *         crunch(null);
       *     }
       *     static void crunch(int[] a) {
       *         mash(a);
       *     }
       *
       *     static void mash(int[] b) {
       *         System.out.println(b[0]);
       *     }
       * }
       * </pre></blockquote>
       *
       * @see     System#err
       */
      public void printStackTrace() {
          synchronized (System.err) {
              printStackTrace(System.err);
          }
      }
  }
  