JdbcTemplate基本使用

笔记四程序源码下载

01-JdbcTemplate基本使用-概述(了解)

JdbcTemplate是spring框架中提供的一个对象，是对原始繁琐的Jdbc API对象的简单封装。spring框架为我们提供了很多的操作模板类。例如：操作关系型数据的JdbcTemplate和HibernateTemplate，操作nosql数据库的RedisTemplate，操作消息队列的JmsTemplate等等。

02-JdbcTemplate基本使用-开发步骤(理解)

①导入spring-jdbc和spring-tx坐标

②创建数据库表和实体

③创建JdbcTemplate对象

④执行数据库操作

03-JdbcTemplate基本使用-快速入门代码实现(应用)

导入spring-jdbc和spring-tx坐标

<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.itheima</groupId><artifactId>itheima_spring_jdbc</artifactId><version>1.0-SNAPSHOT</version><packaging>war</packaging><name>itheima_spring_jdbc Maven Webapp</name><!-- FIXME change it to the project's website --><url>http://www.example.com</url><dependencies><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.32</version></dependency><dependency><groupId>c3p0</groupId><artifactId>c3p0</artifactId><version>0.9.1.2</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.10</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-web</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.0.1</version><scope>provided</scope></dependency><dependency><groupId>javax.servlet.jsp</groupId><artifactId>javax.servlet.jsp-api</artifactId><version>2.2.1</version><scope>provided</scope></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-core</artifactId><version>2.9.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.9.0</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-annotations</artifactId><version>2.9.0</version></dependency><dependency><groupId>commons-fileupload</groupId><artifactId>commons-fileupload</artifactId><version>1.3.1</version></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.3</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.0.5.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>5.0.5.RELEASE</version></dependency></dependencies>
</project>

创建数据库表和实体

package com.itheima.domain;public class Account {private String name;private double money;public String getNa me() {return name;}public void setName(String name) {this.name = name;}public double getMoney() {return money;}public void setMoney(double money) {this.money = money;}@Overridepublic String toString() {return "Account{" +"name='" + name + '\'' +", money=" + money +'}';}
}

创建JdbcTemplate对象

执行数据库操作

@Test//测试JdbcTemplate开发步骤public void test1() throws PropertyVetoException {//创建数据源对象ComboPooledDataSource dataSource = new ComboPooledDataSource();dataSource.setDriverClass("com.mysql.jdbc.Driver");dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");dataSource.setUser("root");dataSource.setPassword("root");JdbcTemplate jdbcTemplate = new JdbcTemplate();//设置数据源对象  知道数据库在哪jdbcTemplate.setDataSource(dataSource);//执行操作int row = jdbcTemplate.update("insert into account values(?,?)", "tom", 5000);System.out.println(row);}

04-JdbcTemplate基本使用-spring产生模板对象分析(理解)

我们可以将JdbcTemplate的创建权交给Spring，将数据源DataSource的创建权也交给Spring，在Spring容器内部将数据源DataSource注入到JdbcTemplate模版对象中,然后通过Spring容器获得JdbcTemplate对象来执行操作。

05-JdbcTemplate基本使用-spring产生模板对象代码实现(应用)

配置如下：

<!--数据源对象--><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="com.mysql.jdbc.Driver"></property><property name="jdbcUrl" value="jdbc:mysql:///test"></property><property name="user" value="root"></property><property name="password" value="root"></property></bean><!--jdbc模板对象--><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="dataSource"/></bean>

测试代码

 @Test//测试Spring产生jdbcTemplate对象public void test2() throws PropertyVetoException {ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");JdbcTemplate jdbcTemplate = app.getBean(JdbcTemplate.class);int row = jdbcTemplate.update("insert into account values(?,?)", "lisi", 5000);System.out.println(row);}

06-JdbcTemplate基本使用-spring产生模板对象代码实现（抽取jdbc.properties）(应用)

将数据库的连接信息抽取到外部配置文件中，和spring的配置文件分离开，有利于后期维护

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=root

配置文件修改为:

<?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
"><!--加载jdbc.properties--><context:property-placeholder location="classpath:jdbc.properties"/><!--数据源对象--><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="${jdbc.username}"/><property name="password" value="${jdbc.password}"/></bean><!--jdbc模板对象--><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><property name="dataSource" ref="dataSource"/></bean></beans>

07-JdbcTemplate基本使用-常用操作-更新操作(应用)

package com.itheima.test;import com.itheima.domain.Account;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import java.util.List;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {@Autowiredprivate JdbcTemplate jdbcTemplate;//修改更新@Testpublic void testUpdate(){jdbcTemplate.update("update account set money=? where name=?",10000,"tom");}//删除@Testpublic void testDelete(){jdbcTemplate.update("delete from account where name=?","tom");}}

08-JdbcTemplate基本使用-常用操作-查询操作(应用)

package com.itheima.test;import com.itheima.domain.Account;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import java.util.List;@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {@Autowiredprivate JdbcTemplate jdbcTemplate;//聚合查询@Testpublic void testQueryCount(){Long count = jdbcTemplate.queryForObject("select count(*) from account", Long.class);System.out.println(count);}//查询一个@Testpublic void testQueryOne(){Account account = jdbcTemplate.queryForObject("select * from account where name=?", new BeanPropertyRowMapper<Account>(Account.class), "tom");System.out.println(account);}//查询所有@Testpublic void testQueryAll(){List<Account> accountList = jdbcTemplate.query("select * from account", new BeanPropertyRowMapper<Account>(Account.class));System.out.println(accountList);}}

这里的查询所有的方法是重点，通过在参数中配置一个Bean容器将查询到的数据都填充进实体对象中，这样实体对象Account中就保存了查询的结果。用一个list容器来接收。

总结