[Java知识库]springboot整合mybatis-plus+durid数据库连接池

一、创建springboot项目

在idea中新建项目，选择springboot initializr,点击next创建项目即可。

【项目】创建时记得勾选lombok，springweb

?

?二、测试项目是否创建成功

在src下创建TestController进行测试

package com.example.sessiondemo.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @description: TestController <br>
 * @date: 2022/7/17 16:54 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
@RestController
@RequestMapping("test/")
public class TestController {


    @GetMapping({"/","/hello"})
    public String hello(){
        return "hello";
    }

}

启动项目测试

?项目能够正常启动并访问，说明第一步项目创建没有问题

三、整合jar包

<?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>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>session-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>session-demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <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>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- druid依赖 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.0</version>
        </dependency>
        <!-- mybatisPlus 核心库 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

四、配置applicartion.yml

server:
  port: 8080   #  配置启动端口号

mybatis:
  mapper-locations:
    - classpath:mapper/*.xml


spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=GMT%2B8&useSSL=FALSE
    username: root  #数据库用户名，root为管理员
    password: 123456 #该数据库用户的密码
    # 使用druid数据源
    type: com.alibaba.druid.pool.DruidDataSource

# mybatis-plus相关配置
mybatis-plus:
  # xml扫描，多个目录用逗号或者分号分隔（告诉 Mapper 所对应的 XML 文件位置）
  mapper-locations: classpath:mapper/*.xml
  # 以下配置均有默认值,可以不设置
  global-config:
    db-config:
      #主键类型 AUTO:"数据库ID自增" INPUT:"用户输入ID",ID_WORKER:"全局唯一ID (数字类型唯一ID)", UUID:"全局唯一ID UUID";
      id-type: auto
      #字段策略 IGNORED:"忽略判断"  NOT_NULL:"非 NULL 判断")  NOT_EMPTY:"非空判断"
      field-strategy: NOT_EMPTY
      #数据库类型
      db-type: MYSQL
  configuration:
    # 是否开启自动驼峰命名规则映射:从数据库列名到Java属性驼峰命名的类似映射
    map-underscore-to-camel-case: true
    # 如果查询结果中包含空值的列，则 MyBatis 在映射的时候，不会映射这个字段
    call-setters-on-nulls: true
    # 这个配置会将执行的sql打印出来，在开发或测试的时候可以用
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

五、创建mybatis-plus配置类

package com.example.sessiondemo.config;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.plugins.PerformanceInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

/**
 * @description: MybatisPlusConfig <br>
 * @date: 2022/7/17 17:30 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
@Component
public class MybatisPlusConfig {

    /**
     * mybatis-plus SQL执行效率插件【生产环境可以关闭】
     */
    @Bean
    public PerformanceInterceptor performanceInterceptor() {
        return new PerformanceInterceptor();
    }
    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

}

六、修改启动类

在启动类上添加mapper扫描.

?七、创建数据库

创建test数据库并创建user表

CREATE TABLE `user` (
  `id` bigint(12) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(8) DEFAULT NULL COMMENT '用户名',
  `password` varchar(50) DEFAULT NULL COMMENT '密码',
  `sex` int(1) DEFAULT '0' COMMENT '性别',
  `phone` varchar(20) DEFAULT NULL COMMENT '手机号',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8

八、创建实体类、mapper、service

package com.example.sessiondemo.pojo;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import java.io.Serializable;

/**
 * @description: User <br>
 * @date: 2022/7/17 17:27 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
@Data

@TableName("user")
public class User implements Serializable {


    @TableId(type = IdType.AUTO)
    private Long id;

    /**
     * 用户名
     */
    private String userName;

    /**
     * 密码
     */
    private String password;

    /**
     * 性别
     */
    private Integer sex;

    /**
     * 手机号
     */
    private String phone;

}

package com.example.sessiondemo.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.sessiondemo.pojo.User;
import org.apache.ibatis.annotations.Mapper;

/**
 * @description: UserMapper <br>
 * @date: 2022/7/17 17:32 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
@Mapper
public interface UserMapper extends BaseMapper<User> {

}

package com.example.sessiondemo.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.sessiondemo.pojo.User;

/**
 * @description: UserService <br>
 * @date: 2022/7/17 17:33 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
public interface UserService extends IService<User> {
}

package com.example.sessiondemo.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.sessiondemo.dao.UserMapper;
import com.example.sessiondemo.pojo.User;
import com.example.sessiondemo.service.UserService;
import org.springframework.stereotype.Service;

/**
 * @description: UserServiceImpl <br>
 * @date: 2022/7/17 17:34 <br>
 * @author: William <br>
 * @version: 1.0 <br>
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
}

九、测试配置是否成功

创建测试

package com.example.sessiondemo;

import com.example.sessiondemo.pojo.User;
import com.example.sessiondemo.service.UserService;
import net.bytebuddy.asm.Advice;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class SessionDemoApplicationTests {

    @Autowired
    UserService userService;

    @Test
    void contextLoads() {
        List<User> users = userService.list();
        users.forEach((item) ->{
            System.out.println("item = " + item);
        });
    }

}

输出结果如下：

?成功执行，并且配置插件生效。