springboot整合druid的完整流程记录

<dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>druid-spring-boot-3-starter</artifactId>
	<version>1.2.20</version>
	
	// 不要用 1.2.18 哦，会报错
	<version>1.2.18</version>
</dependency>

com.alibaba.druid.spring.boot3.autoconfigure.DruidDataSourceAutoConfigure

<?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>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.5</version>
    </parent>

    <groupId>com.atguigu</groupId>
    <artifactId>boot-druid</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!--  web开发的场景启动器 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- 数据库相关配置启动器 jdbctemplate 事务相关-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!-- druid启动器的依赖  -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-3-starter</artifactId>
            <version>1.2.20</version>
        </dependency>

        <!-- 驱动类-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.28</version>
        </dependency>

    </dependencies>

</project>

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource # 使用druid连接池
    druid:
      url: jdbc:mysql:///mybatis-example
      username: root
      password: root
      driver-class-name: com.mysql.cj.jdbc.Driver
      
      # 初始化时建立物理连接的个数
      initial-size: 5
      
      # 连接池的最小空闲数量
      min-idle: 5
      
      # 连接池最大连接数量
      max-active: 20
      
      # 获取连接时最大等待时间，单位毫秒
      max-wait: 60000
      
      # 申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。
      test-while-idle: true
      
      # 既作为检测的间隔时间又作为testWhileIdel执行的依据
      time-between-eviction-runs-millis: 60000
      
      # 销毁线程时检测当前连接的最后活动时间和当前时间差大于该值时，关闭当前连接(配置连接在池中的最小生存时间)
      min-evictable-idle-time-millis: 30000
      
      # 用来检测数据库连接是否有效的sql 必须是一个查询语句(oracle中为 select 1 from dual)
      validation-query: select 1
      
      # 申请连接时会执行validationQuery检测连接是否有效,开启会降低性能,默认为true
      test-on-borrow: false
      
      # 归还连接时会执行validationQuery检测连接是否有效,开启会降低性能,默认为true
      test-on-return: false
      
      # 是否缓存preparedStatement, 也就是PSCache,PSCache对支持游标的数据库性能提升巨大，比如说oracle,在mysql下建议关闭。
      pool-prepared-statements: false
      
      # 要启用PSCache，必须配置大于0，当大于0时，poolPreparedStatements自动触发修改为true。在Druid中，不会存在Oracle下PSCache占用内存过多的问题，可以把这个数值配置大一些，比如说100
      max-pool-prepared-statement-per-connection-size: -1
      
      # 合并多个DruidDataSource的监控数据
      use-global-data-source-stat: true
      

package com.atguigu.pojo;

import lombok.Data;

@Data
public class User {
    private int empId;
    private String empName;
    private double empSalary;
}

package com.atguigu.controller;

import com.atguigu.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("user")
public class UserController {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @GetMapping("findAll")
    public List<User> findAll() {
        String sql = "select * from t_emp";
        List<User> list = jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
        return list;
    }
}

package com.atguigu;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class, args);
    }
}