pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>SpringBoot2jdbc</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SpringBoot2jdbc</name>
    <description>SpringBoot2jdbc</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

操作数据源DataSource

package com.example.springboot2jdbc;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.SQLException;
@SpringBootTest
class SpringBoot2jdbcApplicationTests {
    @Autowired
    DataSource dataSource;//数据源对象，自动装配
    @Test
    void contextLoads() throws SQLException {
        //查看一下默认数据源：结果：class com.zaxxer.hikari.HikariDataSource
        System.out.println(dataSource.getClass());
        //获取数据库链接
        Connection connection =dataSource.getConnection();
        System.out.println(connection);
        //关闭
        connection.close();
    }
}

JDBC模板执行SQL操作

写在控制器里面的，执行调用jdbc模板

package com.example.springboot2jdbc.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
import java.util.Map;
@RestController
public class JDBCController {
    //JDBC定义的模板，这个模板定义了一些写法，可以传入sql语句直接执行，不用自己写繁琐的jdbc了
    @Autowired
    JdbcTemplate jt;
    @GetMapping("/q1")
    public List<Map<String,Object>> queryEmps(){
        return jt.queryForList("select * from t_emp");
    }
    @PostMapping("/u1")
    public int update(@RequestParam("eid") int eid,
                         @RequestParam("empName") String empName,
                         @RequestParam("age") int age,
                         @RequestParam("sex") String sex,
                         @RequestParam("email") String email,
                         @RequestParam("did") int did){
        //多个参数的sql语句可以用？这种占位符，执行方法是按照顺序传参
        String sql = "update t_emp set emp_name=?,age=?,sex=?,email=?,did=? where eid=?";
        return jt.update(sql,empName,age,sex,email,did,eid);
    }
}