/*
 * Copyright (c) 1996, 2014, 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 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>getMessage</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>
 *
 * @since 1.1
 */
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.
 *
 * @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.
 *
 * @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 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.
 *
 * @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.
 *
 */
 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>.
 *
 * @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.
 *
 * @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.
 *
 * @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>.
 *
 * @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;
}