/*
* 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.commons.dbcp;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.NoSuchElementException;
import org.apache.commons.pool.KeyedObjectPool;
import org.apache.commons.pool.KeyedPoolableObjectFactory;
/**
* A {@link DelegatingConnection} that pools {@link PreparedStatement}s.
* <p>
* The {@link #prepareStatement} and {@link #prepareCall} methods, rather than creating a new PreparedStatement
* each time, may actually pull the statement from a pool of unused statements.
* The {@link PreparedStatement#close} method of the returned statement doesn't
* actually close the statement, but rather returns it to the pool.
* (See {@link PoolablePreparedStatement}, {@link PoolableCallableStatement}.)
*
*
* @see PoolablePreparedStatement
* @author Rodney Waldhoff
* @author Dirk Verbeeck
* @version $Revision: 885261 $ $Date: 2009-11-29 15:07:02 -0500 (Sun, 29 Nov 2009) $
*/
public class PoolingConnection extends DelegatingConnection implements Connection, KeyedPoolableObjectFactory {
/** Pool of {@link PreparedStatement}s. and {@link CallableStatement}s */
protected KeyedObjectPool _pstmtPool = null;
/** Prepared Statement type */
private static final byte STATEMENT_PREPAREDSTMT = 0;
/** Callable Statement type */
private static final byte STATEMENT_CALLABLESTMT = 1;
/**
* Constructor.
* @param c the underlying {@link Connection}.
*/
public PoolingConnection(Connection c) {
super(c);
}
/**
* Constructor.
* @param c the underlying {@link Connection}.
* @param pool {@link KeyedObjectPool} of {@link PreparedStatement}s and {@link CallableStatement}s.
*/
public PoolingConnection(Connection c, KeyedObjectPool pool) {
super(c);
_pstmtPool = pool;
}
/**
* Close and free all {@link PreparedStatement}s or {@link CallableStatement} from the pool, and
* close the underlying connection.
*/
public synchronized void close() throws SQLException {
if(null != _pstmtPool) {
KeyedObjectPool oldpool = _pstmtPool;
_pstmtPool = null;
try {
oldpool.close();
} catch(RuntimeException e) {
throw e;
} catch(SQLException e) {
throw e;
} catch(Exception e) {
throw (SQLException) new SQLException("Cannot close connection").initCause(e);
}
}
getInnermostDelegate().close();
}
/**
* Create or obtain a {@link PreparedStatement} from the pool.
* @param sql the sql string used to define the PreparedStatement
* @return a {@link PoolablePreparedStatement}
*/
public PreparedStatement prepareStatement(String sql) throws SQLException {
if (null == _pstmtPool) {
throw new SQLException(
"Statement pool is null - closed or invalid PoolingConnection.");
}
try {
return(PreparedStatement)(_pstmtPool.borrowObject(createKey(sql)));
} catch(NoSuchElementException e) {
throw (SQLException) new SQLException("MaxOpenPreparedStatements limit reached").initCause(e);
} catch(RuntimeException e) {
throw e;
} catch(Exception e) {
throw new SQLNestedException("Borrow prepareStatement from pool failed", e);
}
}
/**
* Create or obtain a {@link PreparedStatement} from the pool.
* @param sql the sql string used to define the PreparedStatement
* @param resultSetType result set type
* @param resultSetConcurrency result set concurrency
* @return a {@link PoolablePreparedStatement}
*/
public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
if (null == _pstmtPool) {
throw new SQLException(
"Statement pool is null - closed or invalid PoolingConnection.");
}
try {
return(PreparedStatement)(_pstmtPool.borrowObject(createKey(sql,resultSetType,resultSetConcurrency)));
} catch(NoSuchElementException e) {
throw (SQLException) new SQLException("MaxOpenPreparedStatements limit reached").initCause(e);
} catch(RuntimeException e) {
throw e;
} catch(Exception e) {
throw (SQLException) new SQLException("Borrow prepareStatement from pool failed").initCause(e);
}
}
/**
* Create or obtain a {@link CallableStatement} from the pool.
* @param sql the sql string used to define the CallableStatement
* @return a {@link PoolableCallableStatement}
* @throws SQLException
* @since 1.3
*/
public CallableStatement prepareCall(String sql) throws SQLException {
try {
return (CallableStatement) (_pstmtPool.borrowObject(createKey(sql, STATEMENT_CALLABLESTMT)));
} catch (NoSuchElementException e) {
throw new SQLNestedException("MaxOpenCallableStatements limit reached", e);
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new SQLNestedException("Borrow callableStatement from pool failed", e);
}
}
/**
* Create or obtain a {@link CallableStatement} from the pool.
* @param sql the sql string used to define the CallableStatement
* @param resultSetType result set type
* @param resultSetConcurrency result set concurrency
* @return a {@link PoolableCallableStatement}
* @throws SQLException
* @since 1.3
*/
public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
try {
return (CallableStatement) (_pstmtPool.borrowObject(createKey(sql, resultSetType,
resultSetConcurrency, STATEMENT_CALLABLESTMT)));
} catch (NoSuchElementException e) {
throw new SQLNestedException("MaxOpenCallableStatements limit reached", e);
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new SQLNestedException("Borrow callableStatement from pool failed", e);
}
}
// TODO: possible enhancement, cache these preparedStatements as well
// public PreparedStatement prepareStatement(String sql, int resultSetType,
// int resultSetConcurrency,
// int resultSetHoldability)
// throws SQLException {
// return super.prepareStatement(
// sql, resultSetType, resultSetConcurrency, resultSetHoldability);
// }
//
// public PreparedStatement prepareStatement(String sql, int autoGeneratedKeys)
// throws SQLException {
// return super.prepareStatement(sql, autoGeneratedKeys);
// }
//
// public PreparedStatement prepareStatement(String sql, int columnIndexes[])
// throws SQLException {
// return super.prepareStatement(sql, columnIndexes);
// }
//
// public PreparedStatement prepareStatement(String sql, String columnNames[])
// throws SQLException {
// return super.prepareStatement(sql, columnNames);
// }
/**
* Create a PStmtKey for the given arguments.
* @param sql the sql string used to define the statement
* @param resultSetType result set type
* @param resultSetConcurrency result set concurrency
*/
protected Object createKey(String sql, int resultSetType, int resultSetConcurrency) {
String catalog = null;
try {
catalog = getCatalog();
} catch (SQLException e) {}
return new PStmtKey(normalizeSQL(sql), catalog, resultSetType, resultSetConcurrency);
}
/**
* Create a PStmtKey for the given arguments.
* @param sql the sql string used to define the statement
* @param resultSetType result set type
* @param resultSetConcurrency result set concurrency
* @param stmtType statement type - either {@link #STATEMENT_CALLABLESTMT} or {@link #STATEMENT_PREPAREDSTMT}
*/
protected Object createKey(String sql, int resultSetType, int resultSetConcurrency, byte stmtType) {
String catalog = null;
try {
catalog = getCatalog();
} catch (SQLException e) {}
return new PStmtKey(normalizeSQL(sql), catalog, resultSetType, resultSetConcurrency, stmtType);
}
/**
* Create a PStmtKey for the given arguments.
* @param sql the sql string used to define the statement
*/
protected Object createKey(String sql) {
String catalog = null;
try {
catalog = getCatalog();
} catch (SQLException e) {}
return new PStmtKey(normalizeSQL(sql), catalog);
}
/**
* Create a PStmtKey for the given arguments.
* @param sql the sql string used to define the statement
* @param stmtType statement type - either {@link #STATEMENT_CALLABLESTMT} or {@link #STATEMENT_PREPAREDSTMT}
*/
protected Object createKey(String sql, byte stmtType) {
String catalog = null;
try {
catalog = getCatalog();
} catch (SQLException e) {}
return new PStmtKey(normalizeSQL(sql), catalog, stmtType);
}
/**
* Normalize the given SQL statement, producing a
* cannonical form that is semantically equivalent to the original.
*/
protected String normalizeSQL(String sql) {
return sql.trim();
}
/**
* {@link KeyedPoolableObjectFactory} method for creating
* {@link PoolablePreparedStatement}s or {@link PoolableCallableStatement}s.
* The <code>stmtType</code> field in the key determines whether
* a PoolablePreparedStatement or PoolableCallableStatement is created.
*
* @param obj the key for the {@link PreparedStatement} to be created
* @see #createKey(String, int, int, byte)
*/
public Object makeObject(Object obj) throws Exception {
if(null == obj || !(obj instanceof PStmtKey)) {
throw new IllegalArgumentException("Prepared statement key is null or invalid.");
} else {
PStmtKey key = (PStmtKey)obj;
if( null == key._resultSetType && null == key._resultSetConcurrency ) {
if (key._stmtType == STATEMENT_PREPAREDSTMT ) {
return new PoolablePreparedStatement(getDelegate().prepareStatement( key._sql), key, _pstmtPool, this);
} else {
return new PoolableCallableStatement(getDelegate().prepareCall( key._sql), key, _pstmtPool, this);
}
} else { // Both _resultSetType and _resultSetConcurrency are non-null here (both or neither are set by constructors)
if(key._stmtType == STATEMENT_PREPAREDSTMT) {
return new PoolablePreparedStatement(getDelegate().prepareStatement(
key._sql, key._resultSetType.intValue(),key._resultSetConcurrency.intValue()), key, _pstmtPool, this);
} else {
return new PoolableCallableStatement( getDelegate().prepareCall(
key._sql,key._resultSetType.intValue(), key._resultSetConcurrency.intValue()), key, _pstmtPool, this);
}
}
}
}
/**
* {@link KeyedPoolableObjectFactory} method for destroying
* PoolablePreparedStatements and PoolableCallableStatements.
* Closes the underlying statement.
*
* @param key ignored
* @param obj the pooled statement to be destroyed.
*/
public void destroyObject(Object key, Object obj) throws Exception {
if(obj instanceof DelegatingPreparedStatement) {
((DelegatingPreparedStatement)obj).getInnermostDelegate().close();
} else {
((PreparedStatement)obj).close();
}
}
/**
* {@link KeyedPoolableObjectFactory} method for validating
* pooled statements. Currently always returns true.
*
* @param key ignored
* @param obj ignored
* @return <tt>true</tt>
*/
public boolean validateObject(Object key, Object obj) {
return true;
}
/**
* {@link KeyedPoolableObjectFactory} method for activating
* pooled statements.
*
* @param key ignored
* @param obj pooled statement to be activated
*/
public void activateObject(Object key, Object obj) throws Exception {
((DelegatingPreparedStatement)obj).activate();
}
/**
* {@link KeyedPoolableObjectFactory} method for passivating
* {@link PreparedStatement}s or {@link CallableStatement}s.
* Invokes {@link PreparedStatement#clearParameters}.
*
* @param key ignored
* @param obj a {@link PreparedStatement}
*/
public void passivateObject(Object key, Object obj) throws Exception {
((PreparedStatement)obj).clearParameters();
((DelegatingPreparedStatement)obj).passivate();
}
public String toString() {
if (_pstmtPool != null ) {
return "PoolingConnection: " + _pstmtPool.toString();
} else {
return "PoolingConnection: null";
}
}
/**
* A key uniquely identifiying {@link PreparedStatement}s.
*/
static class PStmtKey {
/** SQL defining Prepared or Callable Statement */
protected String _sql = null;
/** Result set type */
protected Integer _resultSetType = null;
/** Result set concurrency */
protected Integer _resultSetConcurrency = null;
/** Database catalog */
protected String _catalog = null;
/**
* Statement type. Either STATEMENT_PREPAREDSTMT (PreparedStatement)
* or STATEMENT_CALLABLESTMT (CallableStatement)
*/
protected byte _stmtType = STATEMENT_PREPAREDSTMT;
PStmtKey(String sql) {
_sql = sql;
}
PStmtKey(String sql, String catalog) {
_sql = sql;
_catalog = catalog;
}
PStmtKey(String sql, String catalog, byte stmtType) {
_sql = sql;
_catalog = catalog;
_stmtType = stmtType;
}
PStmtKey(String sql, int resultSetType, int resultSetConcurrency) {
_sql = sql;
_resultSetType = new Integer(resultSetType);
_resultSetConcurrency = new Integer(resultSetConcurrency);
}
PStmtKey(String sql, String catalog, int resultSetType, int resultSetConcurrency) {
_sql = sql;
_catalog = catalog;
_resultSetType = new Integer(resultSetType);
_resultSetConcurrency = new Integer(resultSetConcurrency);
}
PStmtKey(String sql, String catalog, int resultSetType, int resultSetConcurrency, byte stmtType) {
_sql = sql;
_catalog = catalog;
_resultSetType = new Integer(resultSetType);
_resultSetConcurrency = new Integer(resultSetConcurrency);
_stmtType = stmtType;
}
public boolean equals(Object that) {
try {
PStmtKey key = (PStmtKey)that;
return( ((null == _sql && null == key._sql) || _sql.equals(key._sql)) &&
((null == _catalog && null == key._catalog) || _catalog.equals(key._catalog)) &&
((null == _resultSetType && null == key._resultSetType) || _resultSetType.equals(key._resultSetType)) &&
((null == _resultSetConcurrency && null == key._resultSetConcurrency) || _resultSetConcurrency.equals(key._resultSetConcurrency)) &&
(_stmtType == key._stmtType)
);
} catch(ClassCastException e) {
return false;
} catch(NullPointerException e) {
return false;
}
}
public int hashCode() {
if (_catalog==null)
return(null == _sql ? 0 : _sql.hashCode());
else
return(null == _sql ? _catalog.hashCode() : (_catalog + _sql).hashCode());
}
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append("PStmtKey: sql=");
buf.append(_sql);
buf.append(", catalog=");
buf.append(_catalog);
buf.append(", resultSetType=");
buf.append(_resultSetType);
buf.append(", resultSetConcurrency=");
buf.append(_resultSetConcurrency);
buf.append(", statmentType=");
buf.append(_stmtType);
return buf.toString();
}
}
}