Spring 系列之jdbcTemplate的使用

一只胡说八道的猴子

发布于 2020-09-28 10:56:00

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发布于 2020-09-28 10:56:00

文章被收录于专栏：Java系列学习与数据结构算法

Spring系列之 jdbcTemplate

啥是jdncTemplate？

t他是spring框架中提供的一个对象，是对原始的jdbcAPI对象的简单封装，spring框架为我们提供了很多操作，模板类，比如操作关系型数据库的jdbcTemplate，操作nosql数据库的Redis Template，操作消息队列的jmsTemplate等等

JdbcTemplate开发步骤

1.导入sprign-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

1.导入sprign-jdbc和spring-tx坐标

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>5.0.2.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.0.3.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.0.3.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.32</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</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>1.0.9</version>
    </dependency>
</dependencies>

2.创建数据库表和实体

使用sqlyog创建一个表 语句

CREATE TABLE test1(
id INT,
NAME VARCHAR(10)
 );

创建实体

package com.pjh;
public class user {
    private Integer id;
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "user{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

JbdcTemplate快速入门*，不使用spring框架的时候

@Test
    public void test1() throws PropertyVetoException {
    ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
    comboPooledDataSource.setDriverClass("com.mysql.jdbc.Driver");
    comboPooledDataSource.setJdbcUrl("jdbc:mysql://localhost:3309/one");
    comboPooledDataSource.setUser("root");
    comboPooledDataSource.setPassword("1234");
    //创建jdbcTemplate对象
    JdbcTemplate jdbcTemplate = new JdbcTemplate();
    jdbcTemplate.setDataSource(comboPooledDataSource);
    //执行语句
    jdbcTemplate.update("insert into test1 values(?,?)",10,"one");
}

结果

抽取配置文件

配置文件代码：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3309/one
jdbc.name=root
jdbc.password=1234

测试函数操作

@Test
public void test3() throws PropertyVetoException {
    //读取配置文件
    ResourceBundle jdbc = ResourceBundle.getBundle("jdbc");
    //获取连接池
    ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
    //设置参数
    comboPooledDataSource.setDriverClass(jdbc.getString("jdbc.driver"));
    comboPooledDataSource.setJdbcUrl(jdbc.getString("jdbc.url"));
    comboPooledDataSource.setUser(jdbc.getString("jdbc.name"));
    comboPooledDataSource.setPassword(jdbc.getString("jdbc.password"));
    //创建jdbcTemplate对象
    JdbcTemplate jdbcTemplate = new JdbcTemplate();
    jdbcTemplate.setDataSource(comboPooledDataSource);
    jdbcTemplate.update("insert into test1 values(?,?)",13,"three");

}

使用spring创建JdbcTemplate对象 将数据源DataSource与JdbcTemplate的创建权交给Spring并在Spring容器内进行依赖注入配置代码：

<bean id="datasource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="com.mysql.jdbc.Driver"/>
    <property name="jdbcUrl" value="jdbc:mysql://localhost:3309/one"/>
    <property name="user" value="root"/>
    <property name="password" value="1234"/>
</bean>
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="datasource"/>
    </bean>

测试函数

@Test
    public void test2(){
    ClassPathXmlApplicationContext classPathXmlApplicationContext =
            new ClassPathXmlApplicationContext("applicationContext.xml");
    JdbcTemplate jdbcTemplate =(JdbcTemplate) classPathXmlApplicationContext.getBean("jdbcTemplate");
    jdbcTemplate.update("insert into test1 values(?,?)",11,"two");
}

结果成功插入

这个也可以使用读取配置文件的方式 我们首先要导入context的约束路径与命名空间

命名空间： xmlns:context="http://www.springframework.org/schema/context" 约束路径：http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd

配置文件修改

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       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">
<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="${jdbc.name}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="datasource"/>
    </bean>
   <context:property-placeholder location="classpath:jdbc.properties"/>
</beans>

测试代码

 @Test
    public void test4(){
        ClassPathXmlApplicationContext classPathXmlApplicationContext =
                new ClassPathXmlApplicationContext("applicationContext.xml");
        JdbcTemplate jdbcTemplate =(JdbcTemplate) classPathXmlApplicationContext.getBean("jdbcTemplate");
        jdbcTemplate.update("insert into test1 values(?,?)",100,"pjh");
    }

结果成功插入

通过注解的方式来得到JdbcTemplate 使用框架

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
@Autowired
private  JdbcTemplate jdbcTemplate;
    @Test
    public void test7(){
        jdbcTemplate.update("insert into test1 values(?,?)",110,"GGB");

    }

不使用框架

public void test1() throws PropertyVetoException {
    ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();
    comboPooledDataSource.setDriverClass("com.mysql.jdbc.Driver");
    comboPooledDataSource.setJdbcUrl("jdbc:mysql://localhost:3309/one");
    comboPooledDataSource.setUser("root");
    comboPooledDataSource.setPassword("1234");
    //创建jdbcTemplate对象
    JdbcTemplate jdbcTemplate = new JdbcTemplate();
    jdbcTemplate.setDataSource(comboPooledDataSource);
    //执行语句
    jdbcTemplate.update("insert into test1 values(?,?)",10,"one");
}

由二者对比即可看出框架的巨大好处，上面那么长的代码现在只要几行即可解决

JDBCTemplate的常用操作

查询语句

查询数据库中的所有内容

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
@Autowired
private  JdbcTemplate jdbcTemplate;
   @Test
public void test8(){
    String sql="select * from test1 where name=?";
    List<user> query = jdbcTemplate.query(sql, new BeanPropertyRowMapper<user>(user.class));
    for (user user : query) {
        System.out.println(user);
    }
}

结果

查询数据库中的某条内容

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
@Autowired
private  JdbcTemplate jdbcTemplate;
   @Test
 @Test
    public void test9(){
        String sql="select * from test1 where id=?";
        List<user> query = jdbcTemplate.query(sql, new BeanPropertyRowMapper<user>(user.class), 10);
        for (user user : query) {
            System.out.println(user);
        }
    }
}

查询数据库记录的数量

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
@Autowired
private  JdbcTemplate jdbcTemplate;
@Test
public void test90(){
    String sql="select count(*) from test1";
    Long aLong = jdbcTemplate.queryForObject(sql, Long.class);
    System.out.println("记录条数："+aLong);
}
}

删除指定记录

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class test {
@Autowired
private  JdbcTemplate jdbcTemplate;
@Test
public void test11(){
    String sql="delete from test1 where id=11";
    jdbcTemplate.update(sql);
}
}