src/org/hsqldb/jdbc/JDBCStatementBase.java - platform/external/hsqldb - Git at Google

 /* Copyright (c) 2001-2010, The HSQL Development Group
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * Redistributions of source code must retain the above copyright notice, this
  * list of conditions and the following disclaimer.
  *
  * Redistributions in binary form must reproduce the above copyright notice,
  * this list of conditions and the following disclaimer in the documentation
  * and/or other materials provided with the distribution.
  *
  * Neither the name of the HSQL Development Group nor the names of its
  * contributors may be used to endorse or promote products derived from this
  * software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
  * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */


 package org.hsqldb.jdbc;

 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.SQLWarning;

 import org.hsqldb.error.ErrorCode;
 import org.hsqldb.result.Result;
 import org.hsqldb.result.ResultConstants;

 /**
  * Base class for HSQLDB's implementations of java.sql.Statement and
  * java.sql.PreparedStatement. Contains common members and methods.
  *
  * @author fredt@usrs
  * @version 2.0
  * @since 1.9.0
  */

 /**
  * JDBC specification.
  *
  * Closing the Statement closes the ResultSet instance returned. But:
  *
  * Statement can be executed multiple times and return several results. With
  * normal Statement objects, each execution can be for a completely different
  * query. PreparedStatement instances are specifically for multiple use over
  * multiple transactions.
  *
  * ResultSets may be held over commits and span several transactions.
  *
  * There is no real relation between the current state fo an Statement instance
  * and the various ResultSets that it may have returned for different queries.
  */

 /**
  * @todo 1.9.0 - review the following issues:
  *
  * Does not always close ResultSet object directly when closed. Although RS
  * objects will eventually be closed when accessed, the change is not reflected
  * to the server, impacting ResultSets that are held.
  */
 class JDBCStatementBase {

     /**
      * Whether this Statement has been explicitly closed.  A JDBCConnection
      * object now explicitly closes all of its open JDBC Statement objects
      * when it is closed.
      */
     volatile boolean isClosed;

     /** Is escape processing enabled? */
     protected boolean isEscapeProcessing = true;

     /** The connection used to execute this statement. */
     protected JDBCConnection connection;

     /** The maximum number of rows to generate when executing this statement. */
     protected int maxRows;

     /** The number of rows returned in a chunk. */
     protected int fetchSize = 0;

     /** Direction of results fetched. */
     protected int fetchDirection = JDBCResultSet.FETCH_FORWARD;

     /** The result of executing this statement. */
     protected Result resultIn;

     /** Any error returned from a batch execute. */
     protected Result errorResult;

     /** The currently existing generated key Result */
     protected Result generatedResult;

     /** The combined result set properties obtained by executing this statement. */
     protected int rsProperties;

     /** Used by this statement to communicate non-batched requests. */
     protected Result resultOut;

     /** Used by this statement to communicate batched execution requests */
     protected Result batchResultOut;

     /** The currently existing ResultSet object */
     protected JDBCResultSet currentResultSet;

     /** The currently existing ResultSet object for generated keys */
     protected JDBCResultSet generatedResultSet;

     /** The first warning in the chain. Null if there are no warnings. */
     protected SQLWarning rootWarning;

     /** Counter for ResultSet in getMoreResults(). */
     protected int resultSetCounter;

     /** Query timeout in seconds */
     protected int queryTimeout;

     /** connection generation */
     int connectionIncarnation;

     /** Implementation in subclasses */
     public synchronized void close() throws SQLException {}

     /**
      * An internal check for closed statements.
      *
      * @throws SQLException when the connection is closed
      */
     void checkClosed() throws SQLException {

         if (isClosed) {
             throw Util.sqlException(ErrorCode.X_07501);
         }

         if (connection.isClosed) {
             close();

             throw Util.sqlException(ErrorCode.X_08503);
         }

         if (connectionIncarnation != connection.incarnation ) {
             throw Util.sqlException(ErrorCode.X_08503);
         }
     }

     /**
      * processes chained warnings and any generated columns result set
      */
     void performPostExecute() throws SQLException {

         resultOut.clearLobResults();

         generatedResult = null;

         if (resultIn == null) {
             return;
         }

         rootWarning = null;

         Result current = resultIn;

         while (current.getChainedResult() != null) {
             current = current.getUnlinkChainedResult();

             if (current.getType() == ResultConstants.WARNING) {
                 SQLWarning w = Util.sqlWarning(current);

                 if (rootWarning == null) {
                     rootWarning = w;
                 } else {
                     rootWarning.setNextWarning(w);
                 }
             } else if (current.getType() == ResultConstants.ERROR) {
                 errorResult = current;
             } else if (current.getType() == ResultConstants.DATA) {
                 generatedResult = current;
             }
         }

         if (rootWarning != null) {
             connection.setWarnings(rootWarning);
         }

         if (resultIn.isData()) {
             currentResultSet = new JDBCResultSet(connection,
                                                  this, resultIn,
                                                  resultIn.metaData);
         }
     }

     int getUpdateCount() throws SQLException {

         checkClosed();

         return (resultIn == null || resultIn.isData()) ? -1
                                                        : resultIn
                                                        .getUpdateCount();
     }

     ResultSet getResultSet() throws SQLException {

         checkClosed();

         ResultSet result = currentResultSet;

         currentResultSet = null;

         return result;
     }

     boolean getMoreResults() throws SQLException {
         return getMoreResults(CLOSE_CURRENT_RESULT);
     }

     /**
      * Not yet correct for multiple ResultSets. Should keep track of all
      * previous ResultSet objects to be able to close them
      */
     boolean getMoreResults(int current) throws SQLException {

         checkClosed();

         if (resultIn == null) {
             return false;
         }

         if (!resultIn.isData()) {
             resultIn = null;

             return false;
         }

         if (currentResultSet != null && current != KEEP_CURRENT_RESULT) {
             currentResultSet.close();
         }

         resultIn = null;

         return false;
     }

     ResultSet getGeneratedResultSet() throws SQLException {

         if (generatedResultSet != null) {
             generatedResultSet.close();
         }

         if (generatedResult == null) {
             generatedResult = Result.emptyGeneratedResult;
         }

         generatedResultSet = new JDBCResultSet(connection, null,
                                                generatedResult,
                                                generatedResult.metaData);

         return generatedResultSet;
     }

     /**
      * See comment for getMoreResults.
      */
     void closeResultData() throws SQLException {

         if (currentResultSet != null) {
             currentResultSet.close();
         }

         if (generatedResultSet != null) {
             generatedResultSet.close();
         }

         generatedResultSet = null;
         generatedResult    = null;
         resultIn           = null;
     }

     /**
      * JDBC 3 constants
      */
     static final int CLOSE_CURRENT_RESULT  = 1;
     static final int KEEP_CURRENT_RESULT   = 2;
     static final int CLOSE_ALL_RESULTS     = 3;
     static final int SUCCESS_NO_INFO       = -2;
     static final int EXECUTE_FAILED        = -3;
     static final int RETURN_GENERATED_KEYS = 1;
     static final int NO_GENERATED_KEYS     = 2;
 }
	/* Copyright (c) 2001-2010, The HSQL Development Group
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* Redistributions of source code must retain the above copyright notice, this
	* list of conditions and the following disclaimer.
	*
	* Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	*
	* Neither the name of the HSQL Development Group nor the names of its
	* contributors may be used to endorse or promote products derived from this
	* software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
	* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/


	package org.hsqldb.jdbc;

	import java.sql.ResultSet;
	import java.sql.SQLException;
	import java.sql.SQLWarning;

	import org.hsqldb.error.ErrorCode;
	import org.hsqldb.result.Result;
	import org.hsqldb.result.ResultConstants;

	/**
	* Base class for HSQLDB's implementations of java.sql.Statement and
	* java.sql.PreparedStatement. Contains common members and methods.
	*
	* @author fredt@usrs
	* @version 2.0
	* @since 1.9.0
	*/

	/**
	* JDBC specification.
	*
	* Closing the Statement closes the ResultSet instance returned. But:
	*
	* Statement can be executed multiple times and return several results. With
	* normal Statement objects, each execution can be for a completely different
	* query. PreparedStatement instances are specifically for multiple use over
	* multiple transactions.
	*
	* ResultSets may be held over commits and span several transactions.
	*
	* There is no real relation between the current state fo an Statement instance
	* and the various ResultSets that it may have returned for different queries.
	*/

	/**
	* @todo 1.9.0 - review the following issues:
	*
	* Does not always close ResultSet object directly when closed. Although RS
	* objects will eventually be closed when accessed, the change is not reflected
	* to the server, impacting ResultSets that are held.
	*/
	class JDBCStatementBase {

	/**
	* Whether this Statement has been explicitly closed. A JDBCConnection
	* object now explicitly closes all of its open JDBC Statement objects
	* when it is closed.
	*/
	volatile boolean isClosed;

	/** Is escape processing enabled? */
	protected boolean isEscapeProcessing = true;

	/** The connection used to execute this statement. */
	protected JDBCConnection connection;

	/** The maximum number of rows to generate when executing this statement. */
	protected int maxRows;

	/** The number of rows returned in a chunk. */
	protected int fetchSize = 0;

	/** Direction of results fetched. */
	protected int fetchDirection = JDBCResultSet.FETCH_FORWARD;

	/** The result of executing this statement. */
	protected Result resultIn;

	/** Any error returned from a batch execute. */
	protected Result errorResult;

	/** The currently existing generated key Result */
	protected Result generatedResult;

	/** The combined result set properties obtained by executing this statement. */
	protected int rsProperties;

	/** Used by this statement to communicate non-batched requests. */
	protected Result resultOut;

	/** Used by this statement to communicate batched execution requests */
	protected Result batchResultOut;

	/** The currently existing ResultSet object */
	protected JDBCResultSet currentResultSet;

	/** The currently existing ResultSet object for generated keys */
	protected JDBCResultSet generatedResultSet;

	/** The first warning in the chain. Null if there are no warnings. */
	protected SQLWarning rootWarning;

	/** Counter for ResultSet in getMoreResults(). */
	protected int resultSetCounter;

	/** Query timeout in seconds */
	protected int queryTimeout;

	/** connection generation */
	int connectionIncarnation;

	/** Implementation in subclasses */
	public synchronized void close() throws SQLException {}

	/**
	* An internal check for closed statements.
	*
	* @throws SQLException when the connection is closed
	*/
	void checkClosed() throws SQLException {

	if (isClosed) {
	throw Util.sqlException(ErrorCode.X_07501);
	}

	if (connection.isClosed) {
	close();

	throw Util.sqlException(ErrorCode.X_08503);
	}

	if (connectionIncarnation != connection.incarnation ) {
	throw Util.sqlException(ErrorCode.X_08503);
	}
	}

	/**
	* processes chained warnings and any generated columns result set
	*/
	void performPostExecute() throws SQLException {

	resultOut.clearLobResults();

	generatedResult = null;

	if (resultIn == null) {
	return;
	}

	rootWarning = null;

	Result current = resultIn;

	while (current.getChainedResult() != null) {
	current = current.getUnlinkChainedResult();

	if (current.getType() == ResultConstants.WARNING) {
	SQLWarning w = Util.sqlWarning(current);

	if (rootWarning == null) {
	rootWarning = w;
	} else {
	rootWarning.setNextWarning(w);
	}
	} else if (current.getType() == ResultConstants.ERROR) {
	errorResult = current;
	} else if (current.getType() == ResultConstants.DATA) {
	generatedResult = current;
	}
	}

	if (rootWarning != null) {
	connection.setWarnings(rootWarning);
	}

	if (resultIn.isData()) {
	currentResultSet = new JDBCResultSet(connection,
	this, resultIn,
	resultIn.metaData);
	}
	}

	int getUpdateCount() throws SQLException {

	checkClosed();

	return (resultIn == null \|\| resultIn.isData()) ? -1
	: resultIn
	.getUpdateCount();
	}

	ResultSet getResultSet() throws SQLException {

	checkClosed();

	ResultSet result = currentResultSet;

	currentResultSet = null;

	return result;
	}

	boolean getMoreResults() throws SQLException {
	return getMoreResults(CLOSE_CURRENT_RESULT);
	}

	/**
	* Not yet correct for multiple ResultSets. Should keep track of all
	* previous ResultSet objects to be able to close them
	*/
	boolean getMoreResults(int current) throws SQLException {

	checkClosed();

	if (resultIn == null) {
	return false;
	}

	if (!resultIn.isData()) {
	resultIn = null;

	return false;
	}

	if (currentResultSet != null && current != KEEP_CURRENT_RESULT) {
	currentResultSet.close();
	}

	resultIn = null;

	return false;
	}

	ResultSet getGeneratedResultSet() throws SQLException {

	if (generatedResultSet != null) {
	generatedResultSet.close();
	}

	if (generatedResult == null) {
	generatedResult = Result.emptyGeneratedResult;
	}

	generatedResultSet = new JDBCResultSet(connection, null,
	generatedResult,
	generatedResult.metaData);

	return generatedResultSet;
	}

	/**
	* See comment for getMoreResults.
	*/
	void closeResultData() throws SQLException {

	if (currentResultSet != null) {
	currentResultSet.close();
	}

	if (generatedResultSet != null) {
	generatedResultSet.close();
	}

	generatedResultSet = null;
	generatedResult = null;
	resultIn = null;
	}

	/**
	* JDBC 3 constants
	*/
	static final int CLOSE_CURRENT_RESULT = 1;
	static final int KEEP_CURRENT_RESULT = 2;
	static final int CLOSE_ALL_RESULTS = 3;
	static final int SUCCESS_NO_INFO = -2;
	static final int EXECUTE_FAILED = -3;
	static final int RETURN_GENERATED_KEYS = 1;
	static final int NO_GENERATED_KEYS = 2;
	}