/*

 * Copyright (c) 2004, 2013, Oracle and/or its affiliates. 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.xml.soap;

/**

 * An exception that signals that a SOAP exception has occurred. A

 * <code>SOAPException</code> object may contain a <code>String</code>

 * that gives the reason for the exception, an embedded

 * <code>Throwable</code> object, or both. This class provides methods

 * for retrieving reason messages and for retrieving the embedded

 * <code>Throwable</code> object.

 *

 * <P> Typical reasons for throwing a <code>SOAPException</code>

 * object are problems such as difficulty setting a header, not being

 * able to send a message, and not being able to get a connection with

 * the provider.  Reasons for embedding a <code>Throwable</code>

 * object include problems such as input/output errors or a parsing

 * problem, such as an error in parsing a header.

 */

public class SOAPException extends Exception {

    private Throwable cause;

    /**

     * Constructs a <code>SOAPException</code> object with no

     * reason or embedded <code>Throwable</code> object.

     */

    public SOAPException() {

        super();

        this.cause = null;

    }

    /**

     * Constructs a <code>SOAPException</code> object with the given

     * <code>String</code> as the reason for the exception being thrown.

     *

     * @param reason a description of what caused the exception

     */

    public SOAPException(String reason) {

        super(reason);

        this.cause = null;

    }

    /**

     * Constructs a <code>SOAPException</code> object with the given

     * <code>String</code> as the reason for the exception being thrown

     * and the given <code>Throwable</code> object as an embedded

     * exception.

     *

     * @param reason a description of what caused the exception

     * @param cause a <code>Throwable</code> object that is to

     *        be embedded in this <code>SOAPException</code> object

     */

    public SOAPException(String reason, Throwable cause) {

        super(reason);

        initCause(cause);

    }

    /**

     * Constructs a <code>SOAPException</code> object initialized

     * with the given <code>Throwable</code> object.

     */

    public SOAPException(Throwable cause) {

        super(cause.toString());

        initCause(cause);

    }

    /**

     * Returns the detail message for this <code>SOAPException</code>

     * object.

     * <P>

     * If there is an embedded <code>Throwable</code> object, and if the

     * <code>SOAPException</code> object has no detail message of its

     * own, this method will return the detail message from the embedded

     * <code>Throwable</code> object.

     *

     * @return the error or warning message for this

     *         <code>SOAPException</code> or, if it has none, the

     *         message of the embedded <code>Throwable</code> object,

     *         if there is one

     */

    public String getMessage() {

        String message = super.getMessage();

        if (message == null && cause != null) {

            return cause.getMessage();

        } else {

            return message;

        }

    }

    /**

     * Returns the <code>Throwable</code> object embedded in this

     * <code>SOAPException</code> if there is one. Otherwise, this method

     * returns <code>null</code>.

     *

     * @return the embedded <code>Throwable</code> object or <code>null</code>

     *         if there is none

     */

    public Throwable getCause() {

        return cause;

    }

    /**

     * Initializes the <code>cause</code> field of this <code>SOAPException</code>

     * object with the given <code>Throwable</code> object.

     * <P>

     * This method can be called at most once.  It is generally called from

     * within the constructor or immediately after the constructor has

     * returned a new <code>SOAPException</code> object.

     * If this <code>SOAPException</code> object was created with the

     * constructor {@link #SOAPException(Throwable)} or

     * {@link #SOAPException(String,Throwable)}, meaning that its

     * <code>cause</code> field already has a value, this method cannot be

     * called even once.

     *

     * @param  cause the <code>Throwable</code> object that caused this

     *         <code>SOAPException</code> object to be thrown.  The value of this

     *         parameter is saved for later retrieval by the

     *         {@link #getCause()} method.  A <tt>null</tt> value is

     *         permitted and indicates that the cause is nonexistent or

     *         unknown.

     * @return  a reference to this <code>SOAPException</code> instance

     * @throws IllegalArgumentException if <code>cause</code> is this

     *         <code>Throwable</code> object.  (A <code>Throwable</code> object

     *         cannot be its own cause.)

     * @throws IllegalStateException if the cause for this <code>SOAPException</code> object

     *         has already been initialized

     */

    public synchronized Throwable initCause(Throwable cause) {

        if (this.cause != null) {

            throw new IllegalStateException("Can't override cause");

        }

        if (cause == this) {

            throw new IllegalArgumentException("Self-causation not permitted");

        }

        this.cause = cause;

        return this;

    }

}