Hibernate & DBCP
转载 http://wiki.apache.org/commons/DBCP/Hibernate
2010-01-27 Version 5 2005-01-27 Version1
About Hibernate & DBCP
Hibernate 2 includes a limited DBCP ConnectionProvider . Not all features of DBCP were supported and with Hibernate3 this limited implementation was deprecated.
There is an implementation on this page. The original author said:
- The implementation below supports all DBCP features and is a drop in replacement for the default version.
However this is untrue. It fails to support:
-
Almost all hibernate.dbcp.ps.* properties
-
hibernate.dbcp.whenExhaustedAction
- ... maybe more?
so personally I feel rather dubious about using it.
This provider can be used on Hibernate 2 & 3 (with some import statements adjustments).
DBCPConnectionProvider
/*
* Copyright 2004 The Apache Software Foundation.
*
* Licensed 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.hibernate.connection;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.Properties;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.cfg.Environment;
/**
* <p>A connection provider that uses an Apache commons DBCP connection pool.</p>
*
* <p>To use this connection provider set:<br>
* <code>hibernate.connection.provider_class org.hibernate.connection.DBCPConnectionProvider</code></p>
*
* <pre>Supported Hibernate properties:
* hibernate.connection.driver_class
* hibernate.connection.url
* hibernate.connection.username
* hibernate.connection.password
* hibernate.connection.isolation
* hibernate.connection.autocommit
* hibernate.connection.pool_size
* hibernate.connection (JDBC driver properties)</pre>
* <br>
* All DBCP properties are also supported by using the hibernate.dbcp prefix.
* A complete list can be found on the DBCP configuration page:
* <a href="http://jakarta.apache.org/commons/dbcp/configuration.html">http://jakarta.apache.org/commons/dbcp/configuration.html</a>.
* <br>
* <pre>Example:
* hibernate.connection.provider_class org.hibernate.connection.DBCPConnectionProvider
* hibernate.connection.driver_class org.hsqldb.jdbcDriver
* hibernate.connection.username sa
* hibernate.connection.password
* hibernate.connection.url jdbc:hsqldb:test
* hibernate.connection.pool_size 20
* hibernate.dbcp.initialSize 10
* hibernate.dbcp.maxWait 3000
* hibernate.dbcp.validationQuery select 1 from dual</pre>
*
* <p>More information about configuring/using DBCP can be found on the
* <a href="http://jakarta.apache.org/commons/dbcp/">DBCP website</a>.
* There you will also find the DBCP wiki, mailing lists, issue tracking
* and other support facilities</p>
*
* @see org.hibernate.connection.ConnectionProvider
* @author Dirk Verbeeck
*/
public class DBCPConnectionProvider implements ConnectionProvider {
private static final Log log = LogFactory.getLog(DBCPConnectionProvider.class);
private static final String PREFIX = "hibernate.dbcp.";
private BasicDataSource ds;
// Old Environment property for backward-compatibility (property removed in Hibernate3)
private static final String DBCP_PS_MAXACTIVE = "hibernate.dbcp.ps.maxActive";
// Property doesn't exists in Hibernate2
private static final String AUTOCOMMIT = "hibernate.connection.autocommit";
public void configure(Properties props) throws HibernateException {
try {
log.debug("Configure DBCPConnectionProvider");
// DBCP properties used to create the BasicDataSource
Properties dbcpProperties = new Properties();
// DriverClass & url
String jdbcDriverClass = props.getProperty(Environment.DRIVER);
String jdbcUrl = props.getProperty(Environment.URL);
dbcpProperties.put("driverClassName", jdbcDriverClass);
dbcpProperties.put("url", jdbcUrl);
// Username / password
String username = props.getProperty(Environment.USER);
String password = props.getProperty(Environment.PASS);
dbcpProperties.put("username", username);
dbcpProperties.put("password", password);
// Isolation level
String isolationLevel = props.getProperty(Environment.ISOLATION);
if ((isolationLevel != null) && (isolationLevel.trim().length() > 0)) {
dbcpProperties.put("defaultTransactionIsolation", isolationLevel);
}
// Turn off autocommit (unless autocommit property is set)
String autocommit = props.getProperty(AUTOCOMMIT);
if ((autocommit != null) && (autocommit.trim().length() > 0)) {
dbcpProperties.put("defaultAutoCommit", autocommit);
} else {
dbcpProperties.put("defaultAutoCommit", String.valueOf(Boolean.FALSE));
}
// Pool size
String poolSize = props.getProperty(Environment.POOL_SIZE);
if ((poolSize != null) && (poolSize.trim().length() > 0)
&& (Integer.parseInt(poolSize) > 0)) {
dbcpProperties.put("maxActive", poolSize);
}
// Copy all "driver" properties into "connectionProperties"
Properties driverProps = ConnectionProviderFactory.getConnectionProperties(props);
if (driverProps.size() > 0) {
StringBuffer connectionProperties = new StringBuffer();
for (Iterator iter = driverProps.entrySet().iterator(); iter.hasNext();) {
Map.Entry entry = (Map.Entry) iter.next();
String key = (String) entry.getKey();
String value = (String) entry.getValue();
connectionProperties.append(key).append('=').append(value);
if (iter.hasNext()) {
connectionProperties.append(';');
}
}
dbcpProperties.put("connectionProperties", connectionProperties.toString());
}
// Copy all DBCP properties removing the prefix
for (Iterator iter = props.entrySet().iterator() ; iter.hasNext() ;) {
Map.Entry entry = (Map.Entry) iter.next();
String key = (String) iter.next();
if (key.startsWith(PREFIX)) {
String property = key.substring(PREFIX.length());
String value = (String) entry.getValue();
dbcpProperties.put(property, value);
}
}
// Backward-compatibility
if (props.getProperty(DBCP_PS_MAXACTIVE) != null) {
dbcpProperties.put("poolPreparedStatements", String.valueOf(Boolean.TRUE));
dbcpProperties.put("maxOpenPreparedStatements", props.getProperty(DBCP_PS_MAXACTIVE));
}
// Some debug info
if (log.isDebugEnabled()) {
log.debug("Creating a DBCP BasicDataSource with the following DBCP factory properties:");
StringWriter sw = new StringWriter();
dbcpProperties.list(new PrintWriter(sw, true));
log.debug(sw.toString());
}
// Let the factory create the pool
ds = (BasicDataSource) BasicDataSourceFactory.createDataSource(dbcpProperties);
// The BasicDataSource has lazy initialization
// borrowing a connection will start the DataSource
// and make sure it is configured correctly.
Connection conn = ds.getConnection();
conn.close();
// Log pool statistics before continuing.
logStatistics();
}
catch (Exception e) {
String message = "Could not create a DBCP pool";
log.fatal(message, e);
if (ds != null) {
try {
ds.close();
}
catch (Exception e2) {
// ignore
}
ds = null;
}
throw new HibernateException(message, e);
}
log.debug("Configure DBCPConnectionProvider complete");
}
public Connection getConnection() throws SQLException {
Connection conn = null;
try {
conn = ds.getConnection();
}
finally {
logStatistics();
}
return conn;
}
public void closeConnection(Connection conn) throws SQLException {
try {
conn.close();
}
finally {
logStatistics();
}
}
public void close() throws HibernateException {
log.debug("Close DBCPConnectionProvider");
logStatistics();
try {
if (ds != null) {
ds.close();
ds = null;
}
else {
log.warn("Cannot close DBCP pool (not initialized)");
}
}
catch (Exception e) {
throw new HibernateException("Could not close DBCP pool", e);
}
log.debug("Close DBCPConnectionProvider complete");
}
protected void logStatistics() {
if (log.isInfoEnabled()) {
log.info("active: " + ds.getNumActive() + " (max: " + ds.getMaxActive() + ") "
+ "idle: " + ds.getNumIdle() + "(max: " + ds.getMaxIdle() + ")");
}
}
}