spring教程--JdbcTemplate详解

 Spring的JdbcTemplate

JdbcTemplate模板与DbUtils工具类比较类似.

1 Spring对持久层技术支持:

JDBC:org.springframework.jdbc.core.JdbcTemplate

Hibernate3.0:org.springframework.orm.hibernate3.HibernateTemplate

IBatis(MyBatis):org.springframework.orm.ibatis.SqlMapClientTemplate

JPA:org.springframe work.orm.jpa.JpaTemplate

2 开发JDBCTemplate入门:

第一步:引入相应jar包:

* spring-tx-3.2.0.RELEASE.jar

* spring-jdbc-3.2.0.RELEASE.jar

* mysql驱动.

 

第二步:创建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"       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"><!-- 配置Spring默认的连接池 --><!-- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///spring3_day02"/><property name="username" value="root"/><property name="password" value="123"/></bean> --><!-- 配置DBCP连接池 --><!-- <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///spring3_day02"/><property name="username" value="root"/><property name="password" value="123"/></bean> --><!-- <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">          <property name="location" value="classpath:jdbc.properties"></property></bean> --><context:property-placeholder location="classpath:jdbc.properties"/><!-- 配置c3p0连接池 --><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="${jdbc.driver}"/><property name="jdbcUrl" value="${jdbc.url}"/><property name="user" value="${jdbc.user}"/><property name="password" value="${jdbc.password}"/></bean><!-- 定义jdbctemplate --><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="dataSource"/></bean><bean id="userDao" class="com.sihai.spring3.demo2.UserDao"><property name="jdbcTemplate" ref="jdbcTemplate"/></bean></beans>

第三步:编写一个测试类:

 

package com.sihai.spring3.demo1;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.jdbc.datasource.DriverManagerDataSource;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:applicationContext.xml")public class SpringTest1 {@Autowired@Qualifier("jdbcTemplate")private JdbcTemplate jdbcTemplate;@Testpublic void demo2(){jdbcTemplate.execute("create table user (id int primary key auto_increment,name varchar(20))");}@Testpublic void demo1(){// 创建连接池:DriverManagerDataSource dataSource = new DriverManagerDataSource();// 设置参数:dataSource.setDriverClassName("com.mysql.jdbc.Driver");dataSource.setUrl("jdbc:mysql:///spring3_day02");dataSource.setUsername("root");dataSource.setPassword("123");// 使用JDBC的模板:JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);jdbcTemplate.execute("create table user (id int primary key auto_increment,name varchar(20))");}}

2.1 配置连接池:

Spring默认的连接池:

<!-- 配置Spring默认的连接池 --><bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///spring3_day02"/><property name="username" value="root"/><property name="password" value="123"/></bean>

 

DBCP连接池:

导入jar包:

* com.springsource.org.apache.commons.dbcp-1.2.2.osgi.jar

* com.springsource.org.apache.commons.pool-1.5.3.jar

 

<!-- 配置DBCP连接池 --><bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"><property name="driverClassName" value="com.mysql.jdbc.Driver"/><property name="url" value="jdbc:mysql:///spring3_day02"/><property name="username" value="root"/><property name="password" value="123"/></bean>

 

C3P0连接池:

导入jar包:

* com.springsource.com.mchange.v2.c3p0-0.9.1.2.jar

<!-- 配置c3p0连接池 --><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="com.mysql.jdbc.Driver"/><property name="jdbcUrl" value="jdbc:mysql:///spring3_day02"/><property name="user" value="root"/><property name="password" value="123"/></bean>

 

2.2 参数设置到属性文件中:

在src下创建jdbc.properties

jdbc.driver = com.mysql.jdbc.Driverjdbc.url = jdbc:mysql:///spring3_day02jdbc.user = rootjdbc.password = 123

 

需要在applicationContext.xml 中使用属性文件配置的内容.

 第一种写法:

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">          <property name="location" value="classpath:jdbc.properties"></property></bean>

 

 第二种写法:

<context:property-placeholder location="classpath:jdbc.properties"/>

2.3 JdbcTemplate的CRUD的操作:

Spring框架中提供了对持久层技术支持的类:

JDBC:org.springframework.jdbc.core.support.JdbcDaoSupport

Hibernate 3.0:org.springframework.orm.hibernate3.support.HibernateDaoSupport

iBatis:org.springframework.orm.ibatis.support.SqlMapClientDaoSupport

 

2.3.1 编写DAO的时候:

Public class UserDao extends JdbcDaoSupport{

 

}

 

进行CRUD的操作;

* 保存:update(String sql,Object... args)

* 修改:update(String sql,Object... args)

* 删除:update(String sql,Object... args)

 

2.3.2 查询:

 简单查询:

* select count(*) from user;--- queryForInt(String sql);

* select name from user where id = ?;--- queryForObject(String sql,Class clazz,Object... args);

 

 复杂查询:(返回对象,和对象集合)

* select * from user where id = ?--- queryForObjectString sql,RowMapper<T> rowMapper,Object... args);

* select * from user;--- query(String sql,RowMapper<T> rowMapper,Object... args);

package com.sihai.spring3.demo2;import java.sql.ResultSet;import java.sql.SQLException;import java.util.List;import org.springframework.jdbc.core.RowMapper;import org.springframework.jdbc.core.support.JdbcDaoSupport;public class UserDao extends JdbcDaoSupport{public void add(User user){String sql = "insert into user values (null,?)";this.getJdbcTemplate().update(sql, user.getName());}public void update(User user){String sql = "update user set name = ? where id = ?";this.getJdbcTemplate().update(sql, user.getName(),user.getId());}public void delete(User user){String sql = "delete from user where id = ?";this.getJdbcTemplate().update(sql, user.getId());}public int findCount(){String sql = "select count(*) from user";return this.getJdbcTemplate().queryForInt(sql);}public String findNameById(int id){String sql = "select name from user where id = ?";return this.getJdbcTemplate().queryForObject(sql, String.class, id);}public User findById(int id){String sql = "select * from user where id = ?";User user = this.getJdbcTemplate().queryForObject(sql, new UserRowMapper(), id);return user;}public List<User> findAll(){String sql = "select * from user";return this.getJdbcTemplate().query(sql, new UserRowMapper());}class UserRowMapper implements RowMapper<User>{/** * rs:结果集. * rowNum:行号 */public User mapRow(ResultSet rs, int rowNum) throws SQLException {User user = new User();user.setId(rs.getInt("id"));user.setName(rs.getString("name"));return user;}}}