Java之Spring JdbcTemplate(一篇文章精通系列)

x33g5p2x  于2021-09-19 转载在 Java  
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一、Spring JdbcTemplate基本使用

1、JdbcTemplate概述

它是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。

2、JdbcTemplate开发步骤

  • 导入spring-jdbc和spring-tx坐标
  • 创建数据库表和实体
  • 创建JdbcTemplate对象
  • 执行数据库操作

3、JdbcTemplate快速入门

(1)工程搭建

  • web.xml当中删除一些没有用的依赖

  • 修改pom.xml

<dependencies>
      <!--导入spring的jdbc坐标-->
      <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.0.5.RELEASE</version>
      </dependency>
      <!--导入spring的tx坐标-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.0.5.RELEASE</version>
    </dependency>

  </dependencies>

删除

(2)导入坐标

<!--导入spring的jdbc坐标-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>
        <!--导入spring的tx坐标-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.0.5.RELEASE</version>
        </dependency>

引入一些其他的依赖

<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>
      <scope>test</scope>
    </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>

  </dependencies>
(3)创建accout表和Accout实体

在数据库当中创建该表

package cn.itbluebox.pojo;

public class Account {

    private String name;
    private double money;

    public Account() {
    }

    public Account(String name, double money) {
        this.name = name;
        this.money = money;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getMoney() {
        return money;
    }

    public void setMoney(double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}
(4)创建JdbcTemplateTest对象
  • 执行数据库操作,在这里test有时候不会自动创建出来需要手动创建

package cn.itbluebox.test;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.jdbc.core.JdbcTemplate;

import java.beans.PropertyVetoException;

public class JdbcTemplateTest {

    @Test
    public void test1() throws PropertyVetoException {

        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 知道数据库的位置
        jdbcTemplate.setDataSource(dataSource);
        //执行操作
        int row = jdbcTemplate.update("insert into account values(?,?)", "tom", 50);

        System.out.println(row);

    }

}
  • 运行测试

运行成功

数据库当中插入成功

4、Spring产生JdbcTemplate对象

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,配置如下:

(1)创建jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=root
(2)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.xsd http://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>
(3)创建SpringJdbcTemplateTest类

package cn.itbluebox.test;

import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;

import java.beans.PropertyVetoException;

public class SpringJdbcTemplateTest {

    @Test
    public void testSpringJdbcTemplate() throws PropertyVetoException {

        ClassPathXmlApplicationContext applicationContext =
                new ClassPathXmlApplicationContext("applicationContext.xml");
        JdbcTemplate jdbcTemplate = applicationContext.getBean(JdbcTemplate.class);
        jdbcTemplate.update("insert into account values(?,?)","lucy",50);
    }

}

5、JdbcTemplate的常用操作

(1)修改操作

创建JdbcTemplateCRUDTest 类

package cn.itbluebox.test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {

    @Autowired
    private JdbcTemplate jdbcTemplate;
    @Test
    //测试修改操作
    public void testUpdate(){
        jdbcTemplate.update("update account set money = ? where name = ?",1000,"tom");
    }

}

运行测试

运行成功

(2)查询全部

@Test
    public void testQueryAll(){
        List<Account> query = jdbcTemplate.query("select * from account", new BeanPropertyRowMapper<Account>(Account.class));
        for (Account account : query) {
            System.out.println(account);
        }
    }

运行测试

(3)查询全部

@Test
    public void testDelete(){
        int tom = jdbcTemplate.update("delete from account where name = ?", "tom");
        System.out.println(tom);
    }

运行成功

删除成功

(4)查询单个数据操作操作

在次之前我们先插入一些新的数据

  • 测试查询单个对象操作

@Test
    public void testQueryOne(){

        Account tom = jdbcTemplate.queryForObject("select * from account where name = ?",
                new BeanPropertyRowMapper<Account>(Account.class),
                "tom");
        System.out.println(tom);

    }

运行测试

  • 测试查询单个简单数据操作(聚合查询)

@Test
    public void testQueryCount(){
        Long aLong = jdbcTemplate.queryForObject("select count(*) from account", Long.class);
        System.out.println(aLong);
    }

6、知识要点

导入spring-jdbcspring-tx坐标

创建数据库表和实体

创建JdbcTemplate对象

JdbcTemplate jdbcTemplate = new JdbcTemplate();    
jdbcTemplate.setDataSource(dataSource);

执行数据库操作
更新操作:

jdbcTemplate.update (sql,params)

查询操作:

jdbcTemplate.query (sql,Mapper,params)
jdbcTemplate.queryForObject(sql,Mapper,params)

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