/*
 * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package javax.xml.xpath;

import java.io.PrintWriter;

/**
 * <code>XPathException</code> represents a generic XPath exception.</p>
 *
 * @author  <a href="Norman.Walsh@Sun.com">Norman Walsh</a>
 * @author <a href="mailto:Jeff.Suttor@Sun.COM">Jeff Suttor</a>
 * @since 1.5
 */
public class XPathException extends Exception {

    private final Throwable cause;

    /**
     * <p>Stream Unique Identifier.</p>
     */
    private static final long serialVersionUID = -1837080260374986980L;

    /**
     * <p>Constructs a new <code>XPathException</code>
     * with the specified detail <code>message</code>.</p>
     *
     * <p>The <code>cause</code> is not initialized.</p>
     *
     * <p>If <code>message</code> is <code>null</code>,
     * then a <code>NullPointerException</code> is thrown.</p>
     *
     * @param message The detail message.
     *
     * @throws NullPointerException When <code>message</code> is
     *   <code>null</code>.
     */
    public XPathException(String message) {
        super(message);
        if ( message == null ) {
            throw new NullPointerException ( "message can't be null");
        }
        this.cause = null;
    }

    /**
     * <p>Constructs a new <code>XPathException</code>
     * with the specified <code>cause</code>.</p>
     *
     * <p>If <code>cause</code> is <code>null</code>,
     * then a <code>NullPointerException</code> is thrown.</p>
     *
     * @param cause The cause.
     *
     * @throws NullPointerException if <code>cause</code> is <code>null</code>.
     */
    public XPathException(Throwable cause) {
        super();
        this.cause = cause;
        if ( cause == null ) {
            throw new NullPointerException ( "cause can't be null");
        }
    }

    /**
     * <p>Get the cause of this XPathException.</p>
     *
     * @return Cause of this XPathException.
     */
    public Throwable getCause() {
        return cause;
    }

    /**
     * <p>Print stack trace to specified <code>PrintStream</code>.</p>
     *
     * @param s Print stack trace to this <code>PrintStream</code>.
     */
    public void printStackTrace(java.io.PrintStream s) {
        if (getCause() != null) {
            getCause().printStackTrace(s);
          s.println("--------------- linked to ------------------");
        }

        super.printStackTrace(s);
    }

    /**
     * <p>Print stack trace to <code>System.err</code>.</p>
     */
    public void printStackTrace() {
        printStackTrace(System.err);
    }

    /**
     * <p>Print stack trace to specified <code>PrintWriter</code>.</p>
     *
     * @param s Print stack trace to this <code>PrintWriter</code>.
     */
    public void printStackTrace(PrintWriter s) {

        if (getCause() != null) {
            getCause().printStackTrace(s);
          s.println("--------------- linked to ------------------");
        }

        super.printStackTrace(s);
    }
}
