/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.jdbc.statements;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.sql.SQLWarning;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.TimeUnit;
import org.apache.jena.atlas.iterator.Iter;
import org.apache.jena.jdbc.JdbcCompatibility;
import org.apache.jena.jdbc.connections.JenaConnection;
import org.apache.jena.jdbc.results.AskResults;
import org.apache.jena.jdbc.results.MaterializedSelectResults;
import org.apache.jena.jdbc.results.SelectResults;
import org.apache.jena.jdbc.results.TripleIteratorResults;
import org.apache.jena.jdbc.results.TripleListResults;
import org.apache.jena.query.* ;
import org.apache.jena.update.UpdateFactory ;
import org.apache.jena.update.UpdateProcessor ;
import org.apache.jena.update.UpdateRequest ;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract Jena JDBC implementation of a statement that only permits read
* operations
*
*/
public abstract class JenaStatement implements Statement {
private static final Logger LOGGER = LoggerFactory.getLogger(JenaStatement.class);
protected static final int DEFAULT_HOLDABILITY = ResultSet.CLOSE_CURSORS_AT_COMMIT;
protected static final int DEFAULT_FETCH_DIRECTION = ResultSet.FETCH_FORWARD;
protected static final int DEFAULT_FETCH_SIZE = 0;
protected static final boolean DEFAULT_AUTO_COMMIT = JenaConnection.DEFAULT_AUTO_COMMIT;
protected static final int DEFAULT_TRANSACTION_LEVEL = JenaConnection.DEFAULT_ISOLATION_LEVEL;
protected static final int NO_LIMIT = 0;
protected static final int DEFAULT_TYPE = ResultSet.TYPE_FORWARD_ONLY;
protected static final int USE_CONNECTION_COMPATIBILITY = Integer.MIN_VALUE;
private List<String> commands = new ArrayList<String>();
private SQLWarning warnings = null;
private JenaConnection connection;
private ResultSet currResults = null;
private Queue<ResultSet> results = new LinkedList<ResultSet>();
private List<ResultSet> openResults = new ArrayList<ResultSet>();
private boolean closed = false;
private int type = DEFAULT_TYPE;
private int fetchDirection = DEFAULT_FETCH_DIRECTION;
private int fetchSize = DEFAULT_FETCH_SIZE;
private int holdability = DEFAULT_HOLDABILITY;
private int updateCount = 0;
private boolean autoCommit = DEFAULT_AUTO_COMMIT;
private int transactionLevel = DEFAULT_TRANSACTION_LEVEL;
private int maxRows = NO_LIMIT;
@SuppressWarnings("unused")
private boolean escapeProcessing = false;
private int timeout = NO_LIMIT;
private int compatibilityLevel = USE_CONNECTION_COMPATIBILITY;
/**
* Creates a new statement
*
* @param connection
* Connection
* @throws SQLException
* Thrown if the arguments are invalid
*/
public JenaStatement(JenaConnection connection) throws SQLException {
this(connection, DEFAULT_TYPE, DEFAULT_FETCH_DIRECTION, DEFAULT_FETCH_SIZE, DEFAULT_HOLDABILITY, DEFAULT_AUTO_COMMIT,
DEFAULT_TRANSACTION_LEVEL);
}
/**
* Creates a new statement
*
* @param connection
* Connection
* @param type
* Result Set type for result sets produced by this statement
* @param fetchDir
* Fetch Direction
* @param fetchSize
* Fetch Size
* @param holdability
* Result Set holdability
* @param autoCommit
* Auto-commit behaviour
* @param transactionLevel
* Transaction level
* @throws SQLException
* Thrown if there is an error with the statement parameters
*
*/
public JenaStatement(JenaConnection connection, int type, int fetchDir, int fetchSize, int holdability, boolean autoCommit,
int transactionLevel) throws SQLException {
if (connection == null)
throw new SQLException("Cannot create a Statement with a null connection");
this.connection = connection;
this.checkFetchDirection(fetchDir);
this.type = type;
this.fetchDirection = fetchDir;
this.fetchSize = fetchSize;
this.checkHoldability(holdability);
this.holdability = holdability;
this.autoCommit = autoCommit;
this.transactionLevel = transactionLevel;
}
/**
* Gets the underlying {@link JenaConnection} implementation, useful for
* accessing Jena JDBC specific information such as desired JDBC
* compatibility level
*
* @return Underlying Jena Connection
*/
public JenaConnection getJenaConnection() {
return this.connection;
}
/**
* Gets the JDBC compatibility level that is in use, see
* {@link JdbcCompatibility} for explanations
* <p>
* By default this is set at the connection level and inherited, however you
* may call {@link #setJdbcCompatibilityLevel(int)} to set the compatibility
* level for this statement. This allows you to change the compatibility
* level on a per-query basis if so desired.
* </p>
*
* @return Compatibility level
*/
public int getJdbcCompatibilityLevel() {
if (this.compatibilityLevel == USE_CONNECTION_COMPATIBILITY)
return this.connection.getJdbcCompatibilityLevel();
return this.compatibilityLevel;
}
/**
* Sets the JDBC compatibility level that is in use, see
* {@link JdbcCompatibility} for explanations.
* <p>
* By default this is set at the connection level and inherited, however you
* may call {@link #setJdbcCompatibilityLevel(int)} to set the compatibility
* level for this statement. This allows you to change the compatibility
* level on a per-query basis if so desired.
* </p>
* <p>
* Changing the level may not effect existing open objects, behaviour in
* this case will be implementation specific.
* </p>
*
* @param level
* Compatibility level
*/
public void setJdbcCompatibilityLevel(int level) {
if (level == USE_CONNECTION_COMPATIBILITY) {
this.compatibilityLevel = USE_CONNECTION_COMPATIBILITY;
} else {
this.compatibilityLevel = JdbcCompatibility.normalizeLevel(level);
}
}
@Override
public boolean isWrapperFor(Class<?> iface) throws SQLException {
throw new SQLFeatureNotSupportedException();
}
@Override
public <T> T unwrap(Class<T> iface) throws SQLException {
throw new SQLFeatureNotSupportedException();
}
@Override
public void addBatch(String sql) {
this.commands.add(sql);
}
@Override
public void cancel() throws SQLException {
throw new SQLFeatureNotSupportedException();
}
@Override
public void clearBatch() {
this.commands.clear();
}
@Override
public void clearWarnings() {
this.warnings = null;
}
@Override
public void close() throws SQLException {
if (this.closed)
return;
LOGGER.info("Closing statement");
this.closed = true;
// Close current result set (if any)
if (this.currResults != null) {
this.currResults.close();
this.currResults = null;
}
// Close any remaining open results
if (this.results.size() > 0 || this.openResults.size() > 0) {
LOGGER.info("Closing " + (this.results.size() + this.openResults.size()) + " open result sets");
// Queue results i.e. stuff resulting from a query that produced
// multiple result sets or executeBatch() calls
while (!this.results.isEmpty()) {
ResultSet rset = this.results.poll();
if (rset != null)
rset.close();
}
// Close open result sets i.e. stuff left around depending on
// statement correction
for (ResultSet rset : this.openResults) {
rset.close();
}
this.openResults.clear();
LOGGER.info("All open result sets were closed");
}
LOGGER.info("Statement was closed");
}
@Override
public final boolean execute(String sql) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
// Pre-process the command text
LOGGER.info("Received input command text:\n {}", sql);
sql = this.connection.applyPreProcessors(sql);
LOGGER.info("Command text after pre-processing:\n {}", sql);
Query q = null;
UpdateRequest u = null;
try {
// Start by assuming a query
q = QueryFactory.create(sql);
} catch (Exception e) {
try {
// If that fails try as an update instead
u = UpdateFactory.create(sql);
} catch (Exception e2) {
LOGGER.error("Command text was not a valid SPARQL query/update", e2);
throw new SQLException("Not a valid SPARQL query/update", e);
}
}
if (q != null) {
// Execute as a query
LOGGER.info("Treating command text as a query");
return this.executeQuery(q);
} else if (u != null) {
// Execute as an update
LOGGER.info("Treating command text as an update");
this.executeUpdate(u);
return false;
} else {
throw new SQLException("Unable to create a SPARQL query/update");
}
}
private boolean executeQuery(Query q) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
// Do we need transactions?
boolean needsBegin = (!this.autoCommit && this.transactionLevel != Connection.TRANSACTION_NONE && !this
.hasActiveTransaction());
boolean needsCommit = (this.autoCommit && this.transactionLevel != Connection.TRANSACTION_NONE);
// Do this first in a separate try catch so if we fail to start a
// transaction we don't then try to roll it back which can mask the
// actual cause of the error
try {
// Start a transaction if necessary
if (needsCommit) {
LOGGER.info("Running query in auto-commit mode");
this.beginTransaction(ReadWrite.READ);
} else if (needsBegin) {
LOGGER.info("Starting a new transaction to run query, transaction will not be auto-committed");
this.beginTransaction(ReadWrite.WRITE);
}
} catch (Exception e) {
LOGGER.error("Starting the new transaction failed", e);
throw new SQLException("Failed to start a new query transaction", e);
}
try {
// Pre-process the query
q = this.connection.applyPreProcessors(q);
// Manipulate the query if appropriate
if (this.maxRows > NO_LIMIT) {
// If we have no LIMIT or the LIMIT is greater than the
// permitted max rows
// then we will set the LIMIT to the max rows
if (!q.hasLimit() || q.getLimit() > this.maxRows) {
LOGGER.info("Enforced max rows on results by applying LIMIT {} to the query", this.maxRows);
q.setLimit(this.maxRows);
}
}
// Create the query execution
QueryExecution qe = this.createQueryExecution(q);
// Manipulate the query execution if appropriate
if (this.timeout > NO_LIMIT) {
qe.setTimeout(this.timeout, TimeUnit.SECONDS, this.timeout, TimeUnit.SECONDS);
}
// Return the appropriate result set type
if (q.isSelectType()) {
switch (this.type) {
case ResultSet.TYPE_SCROLL_INSENSITIVE:
this.currResults = new MaterializedSelectResults(this, qe, ResultSetFactory.makeRewindable(this.connection
.applyPostProcessors(qe.execSelect())), false);
break;
case ResultSet.TYPE_FORWARD_ONLY:
default:
this.currResults = new SelectResults(this, qe, this.connection.applyPostProcessors(qe.execSelect()),
needsCommit);
break;
}
} else if (q.isAskType()) {
boolean askRes = qe.execAsk();
qe.close();
this.currResults = new AskResults(this, this.connection.applyPostProcessors(askRes), needsCommit);
} else if (q.isDescribeType()) {
switch (this.type) {
case ResultSet.TYPE_SCROLL_INSENSITIVE:
this.currResults = new TripleListResults(this, qe, Iter.toList(this.connection.applyPostProcessors(qe
.execDescribeTriples())), false);
break;
case ResultSet.TYPE_FORWARD_ONLY:
default:
this.currResults = new TripleIteratorResults(this, qe, this.connection.applyPostProcessors(qe
.execDescribeTriples()), needsCommit);
break;
}
} else if (q.isConstructType()) {
switch (this.type) {
case ResultSet.TYPE_SCROLL_INSENSITIVE:
this.currResults = new TripleListResults(this, qe, Iter.toList(this.connection.applyPostProcessors(qe
.execConstructTriples())), false);
break;
case ResultSet.TYPE_FORWARD_ONLY:
default:
this.currResults = new TripleIteratorResults(this, qe, this.connection.applyPostProcessors(qe
.execConstructTriples()), needsCommit);
break;
}
} else {
throw new SQLException("Unknown SPARQL Query type");
}
// Can immediately commit when type is
// TYPE_SCROLL_INSENSITIVE and auto-committing since we have
// already materialized results so don't need the read
// transaction
if (this.type == ResultSet.TYPE_SCROLL_INSENSITIVE && needsCommit) {
LOGGER.info("Auto-committing query transaction since results have been materialized");
this.commitTransaction();
}
return true;
} catch (SQLException e) {
if (needsCommit) {
// When auto-committing and query fails roll back immediately
LOGGER.warn("Rolling back failed query transaction", e);
this.rollbackTransaction();
}
throw e;
} catch (Throwable e) {
LOGGER.error("SPARQL Query evaluation failed", e);
if (needsCommit) {
// When auto-committing and query fails roll back immediately
LOGGER.warn("Rolling back failed query transaction");
this.rollbackTransaction();
}
throw new SQLException("Error occurred during SPARQL query evaluation", e);
}
}
/**
* Helper method which derived classes must implement to provide a query
* execution
*
* @param q
* Query
* @return Query Execution
* @throws SQLException
* Thrown if there is a problem creating a query execution
*/
protected abstract QueryExecution createQueryExecution(Query q) throws SQLException;
private int executeUpdate(UpdateRequest u) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
if (this.connection.isReadOnly())
throw new SQLException("The JDBC connection is currently in read-only mode, updates are not permitted");
// Do we need transactions?
boolean needsBegin = (!this.autoCommit && this.transactionLevel != Connection.TRANSACTION_NONE && !this
.hasActiveTransaction());
boolean needsCommit = (this.autoCommit && this.transactionLevel != Connection.TRANSACTION_NONE);
try {
// Start a Transaction if necessary
if (needsCommit || needsBegin) {
if (this.autoCommit) {
LOGGER.info("Running update in auto-commit mode");
} else {
LOGGER.info("Starting a new transaction to run update, transaction will not be auto-committed");
}
this.beginTransaction(ReadWrite.WRITE);
}
} catch (Exception e) {
LOGGER.error("Starting the new transaction failed", e);
throw new SQLException("Failed to start a new query transaction", e);
}
try {
// Pre-process the update
u = this.connection.applyPreProcessors(u);
// Execute updates
UpdateProcessor processor = this.createUpdateProcessor(u);
processor.execute();
// If auto-committing can commit immediately
if (needsCommit) {
LOGGER.info("Auto-committing update transaction");
this.commitTransaction();
}
return 0;
} catch (SQLException e) {
if (needsCommit) {
LOGGER.warn("Rolling back failed update transaction", e);
this.rollbackTransaction();
}
throw e;
} catch (Exception e) {
LOGGER.error("SPARQL Update evaluation failed", e);
if (needsCommit) {
LOGGER.warn("Rolling back failed update transaction");
this.rollbackTransaction();
}
throw new SQLException("Error occurred during SPARQL update evaluation", e);
}
}
/**
* Helper method which derived classes must implement to provide an update
* processor
*
* @param u
* Update
* @return Update Processor
*/
protected abstract UpdateProcessor createUpdateProcessor(UpdateRequest u) throws SQLException;
protected abstract boolean hasActiveTransaction() throws SQLException;
protected abstract void beginTransaction(ReadWrite type) throws SQLException;
protected abstract void commitTransaction() throws SQLException;
protected abstract void rollbackTransaction() throws SQLException;
@Override
public boolean execute(String sql, int autoGeneratedKeys) throws SQLException {
return this.execute(sql);
}
@Override
public boolean execute(String sql, int[] columnIndexes) throws SQLException {
return this.execute(sql);
}
@Override
public boolean execute(String sql, String[] columnNames) throws SQLException {
return this.execute(sql);
}
@Override
public final int[] executeBatch() throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
// Issue warning where appropriate
if (this.commands.size() > 1 && this.autoCommit && this.holdability == ResultSet.CLOSE_CURSORS_AT_COMMIT) {
this.setWarning("Executing this batch of commands may lead to unexpectedly closed result sets because auto-commit is enabled and commit behaviour is set to close cursors at commit");
}
// Go ahead and process the batch
int[] rets = new int[this.commands.size()];
ResultSet curr = this.currResults;
for (int i = 0; i < this.commands.size(); i++) {
if (this.execute(this.commands.get(i))) {
// True means it returned a ResultSet
this.results.add(this.getResultSet());
this.currResults = null;
rets[i] = SUCCESS_NO_INFO;
} else {
// Need to add a null to getMoreResults() to produce correct
// behavior across subsequent calls to getMoreResults()
this.results.add(null);
rets[i] = this.getUpdateCount();
}
}
this.currResults = curr;
// Make the next available results the current results if there
// are no current results
if (this.currResults == null && !this.results.isEmpty()) {
this.currResults = this.results.poll();
}
return rets;
}
@Override
public final ResultSet executeQuery(String sql) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
// Pre-process the command text
LOGGER.info("Received input command text:\n {}", sql);
sql = this.connection.applyPreProcessors(sql);
LOGGER.info("Command text after pre-processing:\n {}", sql);
Query q = null;
try {
q = QueryFactory.create(sql);
} catch (Exception e) {
LOGGER.error("Invalid SPARQL query", e);
throw new SQLException("Not a valid SPARQL query", e);
}
if (q == null)
throw new SQLException("Unable to create a SPARQL Query");
if (this.executeQuery(q)) {
return this.currResults;
} else {
throw new SQLException("Query did not produce a result set");
}
}
@Override
public final int executeUpdate(String sql) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
if (this.connection.isReadOnly())
throw new SQLException("The JDBC connection is currently in read-only mode, updates are not permitted");
// Pre-process the command text
LOGGER.info("Received input command text:\n {}", sql);
sql = this.connection.applyPreProcessors(sql);
LOGGER.info("Command text after pre-processing:\n {}", sql);
UpdateRequest u = null;
try {
u = UpdateFactory.create(sql);
} catch (Exception e) {
LOGGER.error("Invalid SPARQL update", e);
throw new SQLException("Not a valid SPARQL Update", e);
}
if (u == null)
throw new SQLException("Unable to create a SPARQL Update Request");
return this.executeUpdate(u);
}
@Override
public int executeUpdate(String sql, int autoGeneratedKeys) throws SQLException {
return this.executeUpdate(sql);
}
@Override
public int executeUpdate(String sql, int[] columnIndexes) throws SQLException {
return this.executeUpdate(sql);
}
@Override
public int executeUpdate(String sql, String[] columnNames) throws SQLException {
return this.executeUpdate(sql);
}
@Override
public final Connection getConnection() {
return this.connection;
}
@Override
public int getFetchDirection() {
return this.fetchDirection;
}
@Override
public int getFetchSize() {
return this.fetchSize;
}
@Override
public ResultSet getGeneratedKeys() throws SQLException {
throw new SQLFeatureNotSupportedException();
}
@Override
public int getMaxFieldSize() {
return NO_LIMIT;
}
@Override
public int getMaxRows() {
return maxRows;
}
@Override
public boolean getMoreResults() throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
if (this.currResults != null) {
this.currResults.close();
this.currResults = null;
}
if (!this.results.isEmpty()) {
this.currResults = this.results.poll();
return true;
} else {
return false;
}
}
@Override
public boolean getMoreResults(int current) throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
switch (current) {
case Statement.CLOSE_CURRENT_RESULT:
return this.getMoreResults();
case Statement.CLOSE_ALL_RESULTS:
for (ResultSet rset : this.openResults) {
rset.close();
}
this.openResults.clear();
return this.getMoreResults();
case Statement.KEEP_CURRENT_RESULT:
if (this.currResults != null) {
this.openResults.add(this.currResults);
this.currResults = null;
}
return this.getMoreResults();
default:
throw new SQLFeatureNotSupportedException(
"Unsupported mode for dealing with current results, only Statement.CLOSE_CURRENT_RESULT, Statement.CLOSE_ALL_RESULTS and Statement.KEEP_CURRENT_RESULT are supported");
}
}
@Override
public int getQueryTimeout() {
return this.timeout;
}
@Override
public final ResultSet getResultSet() throws SQLException {
if (this.isClosed())
throw new SQLException("The Statement is closed");
return this.currResults;
}
/**
* Helper method for use in execute() method implementations to set the
* current results
*
* @param results
* Results
* @throws SQLException
* Thrown if there is an error closing the previous results
*/
protected void setCurrentResults(ResultSet results) throws SQLException {
if (this.currResults != null) {
this.currResults.close();
}
this.currResults = results;
}
/**
* Gets that result sets are read-only
*/
@Override
public final int getResultSetConcurrency() {
return ResultSet.CONCUR_READ_ONLY;
}
@Override
public int getResultSetHoldability() {
return this.holdability;
}
protected void checkHoldability(int h) throws SQLException {
switch (h) {
case ResultSet.CLOSE_CURSORS_AT_COMMIT:
case ResultSet.HOLD_CURSORS_OVER_COMMIT:
return;
default:
throw new SQLException(String.format("Holdability %d is supported for Jena JDBC statements", h));
}
}
@Override
public final int getResultSetType() {
return this.type;
}
@Override
public int getUpdateCount() {
return this.updateCount;
}
/**
* Helper method which derived classes may use to set the update count
*
* @param count
* Update Count
*/
protected void setUpdateCount(int count) {
this.updateCount = count;
}
@Override
public SQLWarning getWarnings() {
return this.warnings;
}
/**
* Helper method that derived classes may use to set warnings
*
* @param warning
* Warning
*/
protected void setWarning(SQLWarning warning) {
LOGGER.warn("SQL Warning was issued", warning);
if (this.warnings == null) {
this.warnings = warning;
} else {
// Chain with existing warnings
warning.setNextWarning(this.warnings);
this.warnings = warning;
}
}
/**
* Helper method that derived classes may use to set warnings
*
* @param warning
* Warning
*/
protected void setWarning(String warning) {
this.setWarning(new SQLWarning(warning));
}
/**
* Helper method that derived classes may use to set warnings
*
* @param warning
* Warning
* @param cause
* Cause
*/
protected void setWarning(String warning, Throwable cause) {
this.setWarning(new SQLWarning(warning, cause));
}
@Override
public final boolean isClosed() {
return this.closed;
}
@Override
public final boolean isPoolable() {
return true;
}
@Override
public void setCursorName(String name) throws SQLException {
throw new SQLFeatureNotSupportedException();
}
@Override
public void setEscapeProcessing(boolean enable) {
this.escapeProcessing = enable;
}
@Override
public void setFetchDirection(int direction) throws SQLException {
this.checkFetchDirection(direction);
this.fetchDirection = direction;
}
/**
* Helper method which checks whether a given fetch direction is valid
* throwing an error if it is not
*
* @param dir
* Fetch Direction
* @throws SQLException
* Thrown if the direction is not valid
*/
protected void checkFetchDirection(int dir) throws SQLException {
switch (dir) {
case ResultSet.FETCH_FORWARD:
return;
default:
throw new SQLFeatureNotSupportedException("Only ResultSet.FETCH_FORWARD is supported as a fetch direction");
}
}
@Override
public void setFetchSize(int rows) {
this.fetchSize = rows;
}
@Override
public void setMaxFieldSize(int max) {
// Ignored
this.setWarning("setMaxFieldSize() was called but there is no field size limit for Jena JDBC connections");
}
@Override
public void setMaxRows(int max) {
if (max <= NO_LIMIT) {
this.maxRows = NO_LIMIT;
} else {
this.maxRows = max;
}
}
@Override
public void setPoolable(boolean poolable) {
// Ignored
this.setWarning("setPoolable() was called but Jena JDBC statements are always considered poolable");
}
@Override
public void setQueryTimeout(int seconds) {
if (seconds <= NO_LIMIT) {
this.timeout = NO_LIMIT;
} else {
this.timeout = seconds;
}
}
// Java 6/7 compatibility
@SuppressWarnings("javadoc")
public boolean isCloseOnCompletion() {
// Statements do not automatically close
return false;
}
@SuppressWarnings("javadoc")
public void closeOnCompletion() throws SQLException {
// We don't support the JDBC 4.1 feature of closing statements
// automatically
throw new SQLFeatureNotSupportedException();
}
}