标签:spring 连接池 数据源 c3p0 datasource
1 数据源:可以简单理解为数据的来源。
2 连接池:是缓存一定数量的数据库连接,当程序需要数据库连接的时候,直接在连接池中获取空闲的连接,使用完再放回连接池中,此连接又变成空闲状态,等待下一次连接。有于开启连接和关闭连接比较耗费系统资源,有类连接池的管理可以减少这方面的开支。
3 常见连接池:c3p0,dbcp,proxool是常见开源的三种连接池。Spring提供的DriverManagerDataSource总是新建一个连接,根本没有起到连接池的作用。
4 连接池获取连接的方法: Connection conn=dataSource.getConnection();
5 如下是数据源的使用:
c3p0:
UserDao:
package com.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import javax.sql.DataSource;
public class UserDao {
private DataSource dataSource;
public DataSource getDataSource() {
return dataSource;
}
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}
public void save(){
try {
Connection conn=dataSource.getConnection();
String sql="insert into t_student values(?,?)";
PreparedStatement ps=conn.prepareStatement(sql);
ps.setInt(1, 1);
ps.setString(2, "zhang");
ps.executeUpdate();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
UserService:
package com.service;
import com.dao.UserDao;
public class UserService {
private UserDao userDao;
public UserDao getUserDao() {
return userDao;
}
public void setUserDao(UserDao userDao) {
this.userDao = userDao;
}
public void save(){
userDao.save();
}
}
applicationContext.xml:
<?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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd"> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="oracle.jdbc.driver.OracleDriver"></property> <property name="jdbcUrl" value="jdbc:oracle:thin:@localhost:1521:XE"></property> <property name="user" value="orcl"></property> <property name="password" value="newsnews"></property> </bean> <bean id="userDao" class="com.dao.UserDao"> <property name="dataSource" ref="dataSource"></property> </bean> <bean id="userService" class="com.service.UserService"> <property name="userDao" ref="userDao"></property> </bean> </beans>
测试类:
package com.aop;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.service.UserService;
public class Test {
public static void main(String[] args) {
ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
UserService uc=(UserService) ac.getBean("userService");
uc.save();
}
}
标签:spring 连接池 数据源 c3p0 datasource
原文地址:http://blog.csdn.net/liangwenmail/article/details/47667237