在Hibernate中进行dbcp连接池配置

2022-09-13 08:57:23
821次极悦

相信大家对什么是Hibernate已经有所了解，在本教程中，我们将向您展示如何将 Apache DBCP 连接池与 Hibernate 框架集成。

1. 获取 DBCP jar

要将 DBCP 与 Hibernate 集成，您需要commons-dbcp.jar和commons-pool-1.5.4.jar。

文件：pom.xml

<project ...>
	<repositories>
		<repository>
			<id>JBoss repository</id>
			<url>http://repository.jboss.org/nexus/content/groups/public/</url>
		</repository>
	</repositories>
	<dependencies>
		<dependency>
			<groupId>org.hibernate</groupId>
			<artifactId>hibernate-core</artifactId>
			<version>3.6.3.Final</version>
		</dependency>
		<dependency>
			<groupId>commons-dbcp</groupId>
			<artifactId>commons-dbcp</artifactId>
			<version>1.4</version>
		</dependency>
	</dependencies>
</project>

2.DBCPConnectionProvider

要将 DBCP 与 Hibernate 集成，您需要创建一个“ DBCPConnectionProvider ”类。

文件：DBCPConnectionProvider.java

package com.mkyong.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.dbcp.BasicDataSourceFactory;
import org.hibernate.HibernateException;
import org.hibernate.cfg.Environment;
import org.hibernate.connection.ConnectionProvider;
import org.hibernate.connection.ConnectionProviderFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class DBCPConnectionProvider implements ConnectionProvider {
	private static final Logger log = LoggerFactory
			.getLogger(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) entry.getKey();
				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()) {
				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.error(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() + ")");
		}
	}
	public boolean supportsAggressiveRelease() {
		return false;
	}
}

3.在hibernate.cfg.xml中配置DBCP

现在，链接您的“ DBCPConnectionProvider ”并在“ hibernate.cfg.xml ”中定义 DBCP 属性，例如：

文件：hibernate.cfg.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
 <session-factory>
  <property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
  <property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:MKYONG</property>
  <property name="hibernate.connection.username">mkyong</property>
  <property name="hibernate.connection.password">password</property>
  <property name="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</property>
  <property name="hibernate.default_schema">MKYONG</property>
  <property name="show_sql">true</property>  
  <property name="hibernate.connection.provider_class">
	com.mkyong.util.DBCPConnectionProvider
  </property>
  <property name="hibernate.dbcp.initialSize">8</property>
  <property name="hibernate.dbcp.maxActive">20</property>
  <property name="hibernate.dbcp.maxIdle">20</property>
  <property name="hibernate.dbcp.minIdle">0</property>         
  <mapping class="com.mkyong.user.DBUser"></mapping>
</session-factory>
</hibernate-configuration>