springboot之jdbc、druid、mybatis

springboot整合jdbc

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.52.3:3306/mybatis?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC
    username: root
    password: root

<?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>2.5.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>spring-boot-jdbc</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-jdbc</name>
    <description>Spring Boot整合jdbc</description>
    <packaging>jar</packaging>
    <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.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>


</project>

package com.example.jdbc;

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 SpringBootJdbcApplicationTests {


    @Autowired
    DataSource dataSource;

    @Test
    void contextLoads() throws SQLException {

        // 查看默认的数据源 class com.zaxxer.hikari.HikariDataSource
        System.out.println(dataSource.getClass());

        // 获得数据库连接
        Connection connection = dataSource.getConnection();
        // HikariProxyConnection@1242874959 wrapping com.mysql.cj.jdbc.ConnectionImpl@f08fdce
        // Hikari使用jdbc实现
        System.out.println(connection);

        // springboot中会有大量的 xxxTemplate，就是springboot为我们写好的bean，直接拿来用就可以了
        // 在实际开发中我们用JdbcTemplate即可，DataSource在有需要的时候用就行


        connection.close();
    }

}

package com.example.jdbc.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.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;
import java.util.Map;

@RestController
public class JDBCController {

    @Autowired
    JdbcTemplate jdbcTemplate;


    @GetMapping("userList")
    public List<Map<String,Object>> userList(){
        String sql = "select * from user";
        return jdbcTemplate.queryForList(sql);
    }


    @GetMapping("addUser")
    public void addUser(){
        String sql = "insert into user values (3,'弗兰克','9999')";
        jdbcTemplate.update(sql);
    }


    @GetMapping("updateUser")
    public void updateUser(){
        String sql = "update user set pwd=? where id=?";

        Object[] objects = new Object[2];
        objects[0] = 2;
        objects[1] = 1;

        jdbcTemplate.update(sql,objects);
    }


    @GetMapping("delUser/{id}")
    public void delUser(@PathVariable("id") String id){
        String sql = "delete from user where id = ?";
        jdbcTemplate.update(sql,id);
    }
}