/*

 * 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

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

 *

 * 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.

 *

 */

package java.sql;

import java.util.Iterator;

import java.util.NoSuchElementException;

import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;

/**

 * <P>An exception that provides information on a database access

 * error or other errors.

 *

 * <P>Each <code>SQLException</code> provides several kinds of information:

 * <UL>

 *   <LI> a string describing the error.  This is used as the Java Exception

 *       message, available via the method <code>getMesasge</code>.

 *   <LI> a "SQLstate" string, which follows either the XOPEN SQLstate conventions

 *        or the SQL:2003 conventions.

 *       The values of the SQLState string are described in the appropriate spec.

 *       The <code>DatabaseMetaData</code> method <code>getSQLStateType</code>

 *       can be used to discover whether the driver returns the XOPEN type or

 *       the SQL:2003 type.

 *   <LI> an integer error code that is specific to each vendor.  Normally this will

 *       be the actual error code returned by the underlying database.

 *   <LI> a chain to a next Exception.  This can be used to provide additional

 *       error information.

 *   <LI> the causal relationship, if any for this <code>SQLException</code>.

 * </UL>

 */

public class SQLException extends java.lang.Exception

                          implements Iterable<Throwable> {

    /**

     *  Constructs a <code>SQLException</code> object with a given

     * <code>reason</code>, <code>SQLState</code>  and

     * <code>vendorCode</code>.

     *

     * The <code>cause</code> is not initialized, and may subsequently be

     * initialized by a call to the

     * {@link Throwable#initCause(java.lang.Throwable)} method.

     * <p>

     * @param reason a description of the exception

     * @param SQLState an XOPEN or SQL:2003 code identifying the exception

     * @param vendorCode a database vendor-specific exception code

     */

    public SQLException(String reason, String SQLState, int vendorCode) {

        super(reason);

        this.SQLState = SQLState;

        this.vendorCode = vendorCode;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                DriverManager.println("SQLState(" + SQLState +

                                                ") vendor code(" + vendorCode + ")");

                printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     * Constructs a <code>SQLException</code> object with a given

     * <code>reason</code> and <code>SQLState</code>.

     *

     * The <code>cause</code> is not initialized, and may subsequently be

     * initialized by a call to the

     * {@link Throwable#initCause(java.lang.Throwable)} method. The vendor code

     * is initialized to 0.

     * <p>

     * @param reason a description of the exception

     * @param SQLState an XOPEN or SQL:2003 code identifying the exception

     */

    public SQLException(String reason, String SQLState) {

        super(reason);

        this.SQLState = SQLState;

        this.vendorCode = 0;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                printStackTrace(DriverManager.getLogWriter());

                DriverManager.println("SQLException: SQLState(" + SQLState + ")");

            }

        }

    }

    /**

     *  Constructs a <code>SQLException</code> object with a given

     * <code>reason</code>. The  <code>SQLState</code>  is initialized to

     * <code>null</code> and the vender code is initialized to 0.

     *

     * The <code>cause</code> is not initialized, and may subsequently be

     * initialized by a call to the

     * {@link Throwable#initCause(java.lang.Throwable)} method.

     * <p>

     * @param reason a description of the exception

     */

    public SQLException(String reason) {

        super(reason);

        this.SQLState = null;

        this.vendorCode = 0;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     * Constructs a <code>SQLException</code> object.

     * The <code>reason</code>, <code>SQLState</code> are initialized

     * to <code>null</code> and the vendor code is initialized to 0.

     *

     * The <code>cause</code> is not initialized, and may subsequently be

     * initialized by a call to the

     * {@link Throwable#initCause(java.lang.Throwable)} method.

     * <p>

     */

    public SQLException() {

        super();

        this.SQLState = null;

        this.vendorCode = 0;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     *  Constructs a <code>SQLException</code> object with a given

     * <code>cause</code>.

     * The <code>SQLState</code> is initialized

     * to <code>null</code> and the vendor code is initialized to 0.

     * The <code>reason</code>  is initialized to <code>null</code> if

     * <code>cause==null</code> or to <code>cause.toString()</code> if

     * <code>cause!=null</code>.

     * <p>

     * @param cause the underlying reason for this <code>SQLException</code>

     * (which is saved for later retrieval by the <code>getCause()</code> method);

     * may be null indicating the cause is non-existent or unknown.

     * @since 1.6

     */

    public SQLException(Throwable cause) {

        super(cause);

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     * Constructs a <code>SQLException</code> object with a given

     * <code>reason</code> and  <code>cause</code>.

     * The <code>SQLState</code> is  initialized to <code>null</code>

     * and the vendor code is initialized to 0.

     * <p>

     * @param reason a description of the exception.

     * @param cause the underlying reason for this <code>SQLException</code>

     * (which is saved for later retrieval by the <code>getCause()</code> method);

     * may be null indicating the cause is non-existent or unknown.

     * @since 1.6

     */

    public SQLException(String reason, Throwable cause) {

        super(reason,cause);

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                    printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     * Constructs a <code>SQLException</code> object with a given

     * <code>reason</code>, <code>SQLState</code> and  <code>cause</code>.

     * The vendor code is initialized to 0.

     * <p>

     * @param reason a description of the exception.

     * @param sqlState an XOPEN or SQL:2003 code identifying the exception

     * @param cause the underlying reason for this <code>SQLException</code>

     * (which is saved for later retrieval by the

     * <code>getCause()</code> method); may be null indicating

     *     the cause is non-existent or unknown.

     * @since 1.6

     */

    public SQLException(String reason, String sqlState, Throwable cause) {

        super(reason,cause);

        this.SQLState = sqlState;

        this.vendorCode = 0;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                printStackTrace(DriverManager.getLogWriter());

                DriverManager.println("SQLState(" + SQLState + ")");

            }

        }

    }

    /**

     * Constructs a <code>SQLException</code> object with a given

     * <code>reason</code>, <code>SQLState</code>, <code>vendorCode</code>

     * and  <code>cause</code>.

     * <p>

     * @param reason a description of the exception

     * @param sqlState an XOPEN or SQL:2003 code identifying the exception

     * @param vendorCode a database vendor-specific exception code

     * @param cause the underlying reason for this <code>SQLException</code>

     * (which is saved for later retrieval by the <code>getCause()</code> method);

     * may be null indicating the cause is non-existent or unknown.

     * @since 1.6

     */

    public SQLException(String reason, String sqlState, int vendorCode, Throwable cause) {

        super(reason,cause);

        this.SQLState = sqlState;

        this.vendorCode = vendorCode;

        if (!(this instanceof SQLWarning)) {

            if (DriverManager.getLogWriter() != null) {

                DriverManager.println("SQLState(" + SQLState +

                                                ") vendor code(" + vendorCode + ")");

                printStackTrace(DriverManager.getLogWriter());

            }

        }

    }

    /**

     * Retrieves the SQLState for this <code>SQLException</code> object.

     *

     * @return the SQLState value

     */

    public String getSQLState() {

        return (SQLState);

    }

    /**

     * Retrieves the vendor-specific exception code

     * for this <code>SQLException</code> object.

     *

     * @return the vendor's error code

     */

    public int getErrorCode() {

        return (vendorCode);

    }

    /**

     * Retrieves the exception chained to this

     * <code>SQLException</code> object by setNextException(SQLException ex).

     *

     * @return the next <code>SQLException</code> object in the chain;

     *         <code>null</code> if there are none

     * @see #setNextException

     */

    public SQLException getNextException() {

        return (next);

    }

    /**

     * Adds an <code>SQLException</code> object to the end of the chain.

     *

     * @param ex the new exception that will be added to the end of

     *            the <code>SQLException</code> chain

     * @see #getNextException

     */

    public void setNextException(SQLException ex) {

        SQLException current = this;

        for(;;) {

            SQLException next=current.next;

            if (next != null) {

                current = next;

                continue;

            }

            if (nextUpdater.compareAndSet(current,null,ex)) {

                return;

            }

            current=current.next;

        }

    }

    /**

     * Returns an iterator over the chained SQLExceptions.  The iterator will

     * be used to iterate over each SQLException and its underlying cause

     * (if any).

     *

     * @return an iterator over the chained SQLExceptions and causes in the proper

     * order

     *

     * @since 1.6

     */

    public Iterator<Throwable> iterator() {

       return new Iterator<Throwable>() {

           SQLException firstException = SQLException.this;

           SQLException nextException = firstException.getNextException();

           Throwable cause = firstException.getCause();

           public boolean hasNext() {

               if(firstException != null || nextException != null || cause != null)

                   return true;

               return false;

           }

           public Throwable next() {

               Throwable throwable = null;

               if(firstException != null){

                   throwable = firstException;

                   firstException = null;

               }

               else if(cause != null){

                   throwable = cause;

                   cause = cause.getCause();

               }

               else if(nextException != null){

                   throwable = nextException;

                   cause = nextException.getCause();

                   nextException = nextException.getNextException();

               }

               else

                   throw new NoSuchElementException();

               return throwable;

           }

           public void remove() {

               throw new UnsupportedOperationException();

           }

       };

    }

    /**

         * @serial

         */

    private String SQLState;

        /**

         * @serial

         */

    private int vendorCode;

        /**

         * @serial

         */

    private volatile SQLException next;

    private static final AtomicReferenceFieldUpdater<SQLException,SQLException> nextUpdater =

            AtomicReferenceFieldUpdater.newUpdater(SQLException.class,SQLException.class,"next");

    private static final long serialVersionUID = 2135244094396331484L;

}