/**
 * Copyright 2003 IBM Corporation and Sun Microsystems, Inc.
 * All rights reserved.
 * Use is subject to license terms.
 */

package javax.portlet;


/**
 * The <CODE>PortletException</CODE> class defines a general exception
 * that a portlet can throw when it is unable to perform its operation
 * successfully.
 */

public class PortletException extends java.lang.Exception {

    private Throwable _cause;


    /**
     * Constructs a new portlet exception.
     */

    public PortletException() {
        super();
    }

    /**
     * Constructs a new portlet exception with the given text. The
     * portlet container may use the text write it to a log.
     *
     * @param text the exception text
     */

    public PortletException(String text) {
        super(text);
    }

    /**
     * Constructs a new portlet exception when the portlet needs to do
     * the following:
     * <ul>
     * <li>throw an exception
     * <li>include the "root cause" exception
     * <li>include a description message
     * </ul>
     *
     * @param text  the exception text
     * @param cause the root cause
     */

    public PortletException(String text, Throwable cause) {
        super(text);
        _cause = cause;
        // change this when going to jdk1.4:    super (text, cause);
    }

    /**
     * Constructs a new portlet exception when the portlet needs to throw an
     * exception. The exception's message is based on the localized message
     * of the underlying exception.
     *
     * @param cause the root cause
     */

    public PortletException(Throwable cause) {
        _cause = cause;
        // change this when going to jdk1.4:        super (cause);
    }

    /**
     * Prints the stack trace of this exception to the standard error stream.
     */
    public void printStackTrace() {
        this.printStackTrace(System.err);
    }

    /**
     * Prints the stack trace of this exception to the specified print stream.
     *
     * @param out the <code>PrintStream</code> to be used for output
     */
    public void printStackTrace(java.io.PrintStream out) {
        this.printStackTrace(new java.io.PrintWriter(out, true));
    }

    /**
     * Prints the stack trace of this exception to the specified print writer.
     *
     * @param out the <code>PrintWriter</code> to be used for output
     */
    public void printStackTrace(java.io.PrintWriter out) {
        super.printStackTrace(out);

        if (getCause() != null) {
            out.println();
            out.print("Nested Exception is ");
            getCause().printStackTrace(out);
        }
        // change this when going tojdk1.4:
        /*
          super.printStackTrace(out);

          if( getRootCause () != null )
          {
              out.println();
              out.print("Nested Exception is ");
              getRootCause ().printStackTrace(out);
          }
          */
    }

    /**
     * Returns the cause of this throwable or <code>null</code> if the
     * cause is nonexistent or unknown.  (The cause is the throwable that
     * caused this throwable to get thrown.)
     * <p/>
     * <p>This implementation returns the cause that was supplied via one of
     * the constructors requiring a <tt>Throwable</tt>.
     *
     * @return the cause of this throwable or <code>null</code> if the
     *         cause is nonexistent or unknown.
     */
    public Throwable getCause() {
        return (_cause != null ? _cause : null);
    }

}
