spring教程--JdbcTemplate詳解
阿新 • • 發佈：2019-02-06
Spring的JdbcTemplate
JdbcTemplate模板與DbUtils工具類比較類似.
1 Spring對持久層技術支援:
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 開發JDBCTemplate入門:
第一步:引入相應jar包:
* spring-tx-3.2.0.RELEASE.jar
* spring-jdbc-3.2.0.RELEASE.jar
* mysql驅動.
第二步:建立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.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- 配置Spring預設的連線池 --> <!-- <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連線池 --> <!-- <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連線池 --> <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> <!-- 定義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:編寫一個測試類:
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; @Test public void demo2(){ jdbcTemplate.execute("create table user (id int primary key auto_increment,name varchar(20))"); } @Test public void demo1(){ // 建立連線池: DriverManagerDataSource dataSource = new DriverManagerDataSource(); // 設定引數: 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 配置連線池:
Spring預設的連線池:
<!-- 配置Spring預設的連線池 -->
<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連線池:
匯入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連線池 -->
<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連線池:
匯入jar包:
* com.springsource.com.mchange.v2.c3p0-0.9.1.2.jar
<!-- 配置c3p0連線池 -->
<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 引數設定到屬性檔案中:
在src下建立jdbc.properties
jdbc.driver = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql:///spring3_day02
jdbc.user = root
jdbc.password = 123需要在applicationContext.xml 中使用屬性檔案配置的內容.
第一種寫法:
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="classpath:jdbc.properties"></property>
</bean>第二種寫法:
<context:property-placeholder location="classpath:jdbc.properties"/>2.3 JdbcTemplate的CRUD的操作:
Spring框架中提供了對持久層技術支援的類:
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 編寫DAO的時候:
Public class UserDao extends JdbcDaoSupport{
}
進行CRUD的操作;
* 儲存:update(String sql,Object... args)
* 修改:update(String sql,Object... args)
* 刪除:update(String sql,Object... args)
2.3.2 查詢:
簡單查詢:
* select count(*) from user;--- queryForInt(String sql);
* select name from user where id = ?;--- queryForObject(String sql,Class clazz,Object... args);
複雜查詢:(返回物件,和物件集合)
* 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:結果集.
* rowNum:行號
*/
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;
}
}
}