springboot整合mybatis-plus(1) mybatis魂斗罗兄弟p2 实现单表curd零sql

1：简介

MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。（官方原文）
mybatis与MyBatis-Plus的关系，就像我们小时候常玩的魂斗罗一样，一个是p1一个是p2，一个是红色一个是蓝色，两者结合天下无敌。

2：springboot整合mybatis-plus

2.1：引入依赖

        
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <scope>runtimescope>
            <version>8.0.19version>
        dependency>
        
        <dependency>
            <groupId>com.baomidougroupId>
            <artifactId>mybatis-plus-boot-starterartifactId>
            <version>3.3.1.tmpversion>
        dependency>
        <dependency>

2.3: 配置 MapperScan 注解

@SpringBootApplication
@MapperScan("cloud.xingzhe.springbootmybatisplus.mapper")
public class SpringbootMybatisPlusApplication {

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

}

2.3: 配置 分页插件

@EnableTransactionManagement
@Configuration
@MapperScan("cloud.xingzhe.springbootmybatisplus.mapper")
public class MybatisPlusConfig {
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求  默认false
        // paginationInterceptor.setOverflow(false);
        // 设置最大单页限制数量，默认 500 条，-1 不受限制
        // paginationInterceptor.setLimit(500);
        // 开启 count 的 join 优化,只针对部分 left join
        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }
}

2.4：编写配置文件

server:
  port: 8005
spring:
  datasource:
    name: springboot
    url: jdbc:mysql://127.0.0.1:3306/springboot?&useUnicode=true&characterEncoding=utf8&useSSL=FALSE&serverTimezone=Asia/Shanghai
    username: root
    password: root
    # 使用druid数据源
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    filters: stat
    maxActive: 20
    initialSize: 1
    maxWait: 60000
    minIdle: 1
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    maxOpenPreparedStatements: 20
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: cloud.xingzhe.springbootmybatisplus.model
  configuration:
    map-underscore-to-camel-case: true

2.5：创建表

CREATE TABLE `sys_user`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'id' ,
  `username` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL COMMENT '用户名',
  `address` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL COMMENT '地址',
  PRIMARY KEY (`id`)
);
INSERT INTO sys_user VALUES('1','张三','广东');
INSERT INTO sys_user VALUES('2','李四','广西');
INSERT INTO sys_user VALUES('3','王五','北京')

3：代码演示curd

3.1 SysUserMapper.java

package cloud.xingzhe.springbootmybatisplus.mapper;
import cloud.xingzhe.springbootmybatisplus.model.SysUser;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
public interface SysUserMapper extends BaseMapper<SysUser> {
}

注意： BaseMapper是MybatisPlus 自带的

3.2 SysUserMapper.xml

<mapper namespace="cloud.xingzhe.springbootmybatisplus.mapper.SysUserMapper">

mapper>

3.3 SysUserService.java

package cloud.xingzhe.springbootmybatisplus.service;
import cloud.xingzhe.springbootmybatisplus.model.SysUser;
import com.baomidou.mybatisplus.extension.service.IService;
public interface SysUserService extends IService<SysUser> {
}

注意： IService是MybatisPlus 自带的

3.4 SysUserServiceImpl.java

package cloud.xingzhe.springbootmybatisplus.service.impl;
import cloud.xingzhe.springbootmybatisplus.mapper.SysUserMapper;
import cloud.xingzhe.springbootmybatisplus.model.SysUser;
import cloud.xingzhe.springbootmybatisplus.service.SysUserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;
@Service
public class SysUserServiceImpl extends ServiceImpl<SysUserMapper, SysUser> implements SysUserService {
}

注意： ServiceImpl 是MybatisPlus 自带的

3.5 SysUser.java

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
@ApiModel(value = "用户")
@Data
@TableName(value = "sys_user")
public class SysUser {
    @ApiModelProperty("id")
    @TableId(type = IdType.ASSIGN_ID)
    private Long id;
    @ApiModelProperty("用户名称")
    @TableField("username")
    private String username;
    @ApiModelProperty("地址")
    @TableField("address")
    private String address;
}

3.6 SysUserController.java

package cloud.xingzhe.springbootmybatisplus.controller;
import cloud.xingzhe.springbootmybatisplus.model.SysUser;
import cloud.xingzhe.springbootmybatisplus.service.SysUserService;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
@Api(tags = "用户管理")
@RestController
public class SysUserController {
    @Autowired
    private SysUserService sysUserService;
    @ApiOperation(value = "用户添加")
    @RequestMapping(value = "/create",method = RequestMethod.POST)
    public String save(SysUser sysUser){
        boolean flag = sysUserService.save(sysUser);
        return flag?"创建成功":"创建失败";
    }
    @ApiOperation(value = "删除用户")
    @RequestMapping(value = "/delete",method = RequestMethod.DELETE)
    public String delete(String id){
        boolean flag = sysUserService.removeById(id);
        return flag?"删除成功":"删除失败";
    }
    @ApiOperation(value = "更新用户")
    @RequestMapping(value = "/update",method = RequestMethod.POST)
    public String update(SysUser sysUser){
        boolean flag = sysUserService.updateById(sysUser);
        return flag?"更新成功":"更新失败";
    }
    @ApiOperation(value = "获取用户列表")
    @RequestMapping(value = "/list",method = RequestMethod.GET)
    public  List<SysUser> list(){
        List<SysUser> sysUserList = sysUserService.list();
        return sysUserList;
    }
    @ApiOperation(value = "根据id得到用户详情")
    @RequestMapping(value = "/get",method = RequestMethod.GET)
    public SysUser get(String id){
        SysUser sysUser = sysUserService.getById(id);
        return sysUser;
    }
    @ApiOperation(value = "分页查询")
    @RequestMapping(value = "/page",method = RequestMethod.GET)
    public Page<SysUser> page(Integer currentPage,Integer limit){
        Page<SysUser> page=new Page<>(currentPage,limit);
        Page<SysUser> sysUserPage = sysUserService.page(page);
        return sysUserPage;
    }
    @ApiOperation(value = "QueryWrapper查询列表")
    @RequestMapping(value = "/queryWrapperList",method = RequestMethod.GET)
    public List<SysUser> queryWrapperList(SysUser sysUser){
        QueryWrapper<SysUser> queryWrapper=new QueryWrapper<>();
        Map<String,Object> params=new HashMap<>(3);
        params.put("username", sysUser.getUsername());
        params.put("id", sysUser.getId());
        params.put("address", sysUser.getAddress());
        queryWrapper.allEq(params,false);
        List<SysUser> list = sysUserService.list(queryWrapper);
        return list;
    }

}

4：项目目录结构及接口演示截图

4.1：项目结构

4.2 接口文档

4.2 接口文档

4.2.1 用户添加

4.2.2 获取用户列表

4.2.3 分页查询

5：备注

本章：接口文档用到了：swagger2 相应的博文地址：springboog整合swagger2 实现便捷高效的接口文档

javabean用到了： lombok 的注解 相应的博文地址：lombok 一个帮助我们编写javaben中,getter,setter,equals …方法的工具 ideal安装与使用
官方文档：https://mp.baomidou.com/

6：源码地址

https://github.com/xingzhewenzi/springboot-examples.git