前几篇关于Java连接池的介绍都是基于Java应用的,而我们常用的场景是与Spring和ORM框架结合,下面就利用实例学习一下这方面的配置。
1.下载相关内容:
c3p0下载地址:http://sourceforge.net/projects/c3p0/
Proxool下载地址:http://proxool.sourceforge.net/
Druid下载地址:http://code.alibabatech.com/mvn/releases/com/alibaba/druid/
Spring下载地址:http://www.springsource.org/download/community
Hibernate下载地址:http://www.hibernate.org/downloads.html
ibatis(mybatis)下载地址:http://code.google.com/p/mybatis/
这里我们下载并采用的版本是:c3p0-0.9.2.1,proxool-0.9.1,druid-0.2.23,spring-framework-3.2.2,hibernate-4.2.3,mybatis-3.2.2.
2.新建一个web项目,这里以之前举例项目为例,将所需要的相关jar包复制到项目的WEB-INF/lib下,这里就不详细说明各框架的jar包依赖关系了,可以自己百度查下。
3.新建接口C3P0DAO,DruidDAO,ProxoolDAO,并且添加相同的方法:
- /**
- * 获取用户信息
- * @param usrId
- * @return
- */
- Object getUsrInfo(Integer usrId);
4.在resource目录下新建c3p0.properties,druid.properties,proxool.properties这三个属性文件,他们分别是几种连接池的详细配置信息。
5.在resource目录下新建Spring配置文件applicationContext-dataSource.xml,内容如下:
- <?xml version="1.0" encoding="UTF-8"?>
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
- <!-- spring加载资源文件 -->
- <bean name="propertiesConfig"
- class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
- <property name="locations">
- <list>
- <value>classpath:c3p0.properties</value>
- <value>classpath:proxool.properties</value>
- <value>classpath:druid.properties</value>
- <value>classpath:hibernate.properties</value>
- </list>
- </property>
- </bean>
- <!-- c3p0数据源配置 -->
- <bean id="dataSource_c3p0" class="com.mchange.v2.c3p0.ComboPooledDataSource">
- <!-- 数据库驱动 -->
- <property name="driverClass" value="${c3p0.driverClass}" />
- <!-- 数据库连接url -->
- <property name="jdbcUrl" value="${c3p0.jdbcUrl}" />
- <!-- 数据库用户 -->
- <property name="user" value="${c3p0.user}" />
- <!-- 数据库密码 -->
- <property name="password" value="${c3p0.password}" />
- <!-- 初始化时获取连接数 -->
- <property name="initialPoolSize" value="${c3p0.initialPoolSize}" />
- <!-- 连接池中保留的最小连接数 -->
- <property name="minPoolSize" value="${c3p0.minPoolSize}" />
- <!-- 连接池中保留的最大连接数 -->
- <property name="maxPoolSize" value="${c3p0.maxPoolSize}" />
- </bean>
- <!-- Proxool数据源配置 -->
- <bean id="dataSource_proxool" class="org.logicalcobwebs.proxool.ProxoolDataSource">
- <!-- 别名 -->
- <property name="alias" value="${proxool.alias}" />
- <!-- 数据库驱动 -->
- <property name="driver" value="${proxool.driver}" />
- <!-- 数据库连接url -->
- <property name="driverUrl" value="${proxool.driverUrl}" />
- <!-- 数据库用户 -->
- <property name="user" value="${proxool.user}" />
- <!-- 数据库密码 -->
- <property name="password" value="${proxool.password}" />
- <!-- 最少保持的空闲连接数 -->
- <property name="prototypeCount" value="${proxool.prototypeCount}" />
- <!-- 最大连接数 -->
- <property name="maximumConnectionCount" value="${proxool.maximumConnectionCount}" />
- <!-- 最小连接数 -->
- <property name="minimumConnectionCount" value="${proxool.minimumConnectionCount}" />
- </bean>
- <!-- Druid数据源配置 -->
- <bean id="dataSource_druid" class="com.alibaba.druid.pool.DruidDataSource"
- init-method="init" destroy-method="close">
- <!-- 数据库连接url -->
- <property name="url" value="${druid.url}" />
- <!-- 数据库用户 -->
- <property name="username" value="${druid.username}" />
- <!-- 数据库密码 -->
- <property name="password" value="${druid.password}" />
- <!-- 配置连接池初始化大小 -->
- <property name="initialSize" value="${druid.initialSize}" />
- <!-- 最小空闲连接数 -->
- <property name="minIdle" value="${druid.minIdle}" />
- <!-- 最大连接数 -->
- <property name="maxActive" value="${druid.maxActive}" />
- <!-- 获取连接等待超时的时间,单位:毫秒 -->
- <property name="maxWait" value="${druid.maxWait}" />
- </bean>
- </beans>
6.配置Hibernate与Spring集成,新建Spring配置文件applicationContext-hibernate.xml,内容如下:
- <?xml version="1.0" encoding="UTF-8"?>
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
- <!-- c3p0 sessionFactory配置,注意是版本为Hibernate4 -->
- <bean id="sessionFactory_c3p0"
- class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
- <!-- 将c3p0的数据源注入给hibernate使用 -->
- <property name="dataSource" ref="dataSource_c3p0" />
- <property name="mappingResources">
- <list>
- <value>com/test/jdbc/model/User.hbm.xml</value>
- </list>
- </property>
- <property name="hibernateProperties">
- <props>
- <prop key="hibernate.dialect">${hibernate.dialect}</prop>
- <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
- <prop key="hibernate.jdbc.fetch_size">${hibernate.jdbc.fetch_size}</prop>
- <prop key="hibernate.jdbc.batch_size">${hibernate.jdbc.batch_size}</prop>
- <prop key="hibernate.connection.characterEncoding">${hibernate.connection.characterEncoding}</prop>
- <prop key="hibernate.connection.autocommit">${hibernate.connection.autocommit}</prop>
- <prop key="hibernate.connection.release_mode">${hibernate.connection.release_mode}</prop>
- <prop key="hibernate.autoReconnect">${hibernate.autoReconnect}</prop>
- <prop key="hibernate.cglib.use_reflection_optimizer">${hibernate.cglib.use_reflection_optimizer}</prop>
- </props>
- </property>
- </bean>
- <!-- Druid sessionFactory配置,注意是版本为Hibernate4 -->
- <bean id="sessionFactory_druid"
- class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
- <!-- 将c3p0的数据源注入给hibernate使用 -->
- <property name="dataSource" ref="dataSource_druid" />
- <property name="mappingResources">
- <list>
- <value>com/test/jdbc/model/User.hbm.xml</value>
- </list>
- </property>
- <property name="hibernateProperties">
- <props>
- <prop key="hibernate.dialect">${hibernate.dialect}</prop>
- <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
- <prop key="hibernate.jdbc.fetch_size">${hibernate.jdbc.fetch_size}</prop>
- <prop key="hibernate.jdbc.batch_size">${hibernate.jdbc.batch_size}</prop>
- <prop key="hibernate.connection.characterEncoding">${hibernate.connection.characterEncoding}</prop>
- <prop key="hibernate.connection.autocommit">${hibernate.connection.autocommit}</prop>
- <prop key="hibernate.connection.release_mode">${hibernate.connection.release_mode}</prop>
- <prop key="hibernate.autoReconnect">${hibernate.autoReconnect}</prop>
- <prop key="hibernate.cglib.use_reflection_optimizer">${hibernate.cglib.use_reflection_optimizer}</prop>
- </props>
- </property>
- </bean>
- <!-- Proxool sessionFactory配置,注意是版本为Hibernate4 -->
- <bean id="sessionFactory_proxool"
- class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
- <!-- 将c3p0的数据源注入给hibernate使用 -->
- <property name="dataSource" ref="dataSource_proxool" />
- <property name="mappingResources">
- <list>
- <value>com/test/jdbc/model/User.hbm.xml</value>
- </list>
- </property>
- <property name="hibernateProperties">
- <props>
- <prop key="hibernate.dialect">${hibernate.dialect}</prop>
- <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
- <prop key="hibernate.jdbc.fetch_size">${hibernate.jdbc.fetch_size}</prop>
- <prop key="hibernate.jdbc.batch_size">${hibernate.jdbc.batch_size}</prop>
- <prop key="hibernate.connection.characterEncoding">${hibernate.connection.characterEncoding}</prop>
- <prop key="hibernate.connection.autocommit">${hibernate.connection.autocommit}</prop>
- <prop key="hibernate.connection.release_mode">${hibernate.connection.release_mode}</prop>
- <prop key="hibernate.autoReconnect">${hibernate.autoReconnect}</prop>
- <prop key="hibernate.cglib.use_reflection_optimizer">${hibernate.cglib.use_reflection_optimizer}</prop>
- </props>
- </property>
- </bean>
- </beans>
7.实现我们之前定义的三个DAO接口,实现类代码比较简单我拿DruidDAOImpl为例,其他类代码相同:
- package com.test.jdbc.dao.impl;
- import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
- import com.test.jdbc.dao.DruidDAO;
- import com.test.jdbc.model.User;
- /**
- * DruidDAO实现
- * @author g21121
- *
- */
- public class DruidDAOImpl extends HibernateDaoSupport implements DruidDAO {
- /**
- * 获取用户信息
- */
- public Object getUsrInfo(Integer usrId) {
- return getHibernateTemplate().get(User.class, usrId);
- }
- }
8.新建spring配置文件applicationContext-dao.xml,将三个实现类与spring结合:
- <?xml version="1.0" encoding="UTF-8"?>
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
- <!-- 将c3p0作为数据源的sessionFactory注入 -->
- <bean class="com.test.jdbc.dao.impl.C3P0DAOImpl">
- <property name="sessionFactory" ref="sessionFactory_c3p0" />
- </bean>
- <!-- 将Druid作为数据源的sessionFactory注入 -->
- <bean class="com.test.jdbc.dao.impl.DruidDAOImpl">
- <property name="sessionFactory" ref="sessionFactory_druid" />
- </bean>
- <!-- 将Proxool作为数据源的sessionFactory注入 -->
- <bean class="com.test.jdbc.dao.impl.ProxoolDAOImpl">
- <property name="sessionFactory" ref="sessionFactory_proxool" />
- </bean>
- </beans>
这里我们将之前配置的三个数据源注入到了三个不同命名的sessionFactory,然后将三个sessionFactory分别注入到各自的DAO实现类中,这样就实现了利用不同的数据源来访问数据库。
9.新建一个测试用Servlet,代码如下:
- package com.test.jdbc;
- import java.io.IOException;
- import java.io.PrintWriter;
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.beans.factory.annotation.Autowired;
- import com.test.jdbc.dao.C3P0DAO;
- import com.test.jdbc.dao.DruidDAO;
- import com.test.jdbc.dao.ProxoolDAO;
- /**
- * 测试Servlet
- * @author g21121
- *
- */
- public class UserServlet extends HttpServlet {
- /**
- * 此处利用Spring注解自动注入属性
- */
- @Autowired
- private C3P0DAO c3P0DAO;
- @Autowired
- private DruidDAO druidDAO;
- @Autowired
- private ProxoolDAO proxoolDAO;
- /**
- * 处理Get请求
- */
- public void doGet(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- response.setContentType("text/html");
- PrintWriter out = response.getWriter();
- out
- .println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
- out.println("<HTML>");
- out.println(" <HEAD><TITLE>User Servlet</TITLE></HEAD>");
- out.println(" <BODY>");
- out.println("Druid:"+druidDAO.getUsrInfo(1));
- out.println("c3p0:"+c3P0DAO.getUsrInfo(1));
- out.println("Proxool:"+proxoolDAO.getUsrInfo(1));
- out.println(" </BODY>");
- out.println("</HTML>");
- out.flush();
- out.close();
- }
- public void doPost(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- this.doGet(request, response);
- }
- public UserServlet() {
- super();
- }
- }
- <!-- 该 BeanPostProcessor 将自动起作用,对标注 @Autowired 的 Bean 进行自动注入 -->
- <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor" />