Mybatisplus 相关操作之 IService BaseMapper ServiceImpl 简单应用

本篇主要介绍mybatisplus的简单应用

这里对mybatisplus中配置遇到的问题及extent、implement所导入的包也为大家方便引入依赖

1 引入相关依赖

依赖只是参考，每人的仓库不同，代码块内容仅作参考

        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter
        
        
            mysql
            mysql-connector-java
            5.1.47
            runtime
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.20
        
        
            com.baomidou
            mybatisplus-spring-boot-starter
            1.0.5
        
        
            com.baomidou
            mybatis-plus
            3.2.0
        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.3.1
        
        
            com.baomidou
            mybatis-plus-core
            3.2.0
        
        
            org.projectlombok
            lombok
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.0.1
        
        
            com.baomidou
            mybatis-plus-extension
            3.2.0
        
    

2 yml文件配置

部分小伙伴 mysql-connector-java 版本过高，需要将 driver-class-name换成：com.mysql.cj.jdbc.Driver

server:
  port: 9999

# 配置数据源
spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/goods?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=true
    username: root
    password: 123456

3 相关的数据库表数据

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for tb_area
-- ----------------------------
DROP TABLE IF EXISTS `tb_area`;
CREATE TABLE `tb_area`  (
  `area_id` int(2) NOT NULL AUTO_INCREMENT COMMENT '自增id',
  `area_name` varchar(200) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '区域名称',
  `priority` int(2) NOT NULL DEFAULT 0 COMMENT '优先级',
  `create_time` datetime NULL DEFAULT NULL COMMENT '创建时间',
  `update_time` datetime NULL DEFAULT NULL COMMENT '最后修改时间',
  PRIMARY KEY (`area_id`) USING BTREE,
  UNIQUE INDEX `UK_AREA`(`area_name`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 12 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;

SET FOREIGN_KEY_CHECKS = 1;

代码环节

1 目录结构

2 dao数据

import java.io.Serializable;
import java.util.Date;

import com.baomidou.mybatisplus.extension.activerecord.Model;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@AllArgsConstructor
@NoArgsConstructor
public class BaseEntity extends Model {

    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
    private Date createTime;

    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
    private Date updateTime;

    @Override
    protected Serializable pkVal() {
        return super.pkVal();
    }

}

import java.io.Serializable;

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

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@TableName("tb_area")
public class Book extends BaseEntity implements Serializable {

    @TableId(value = "area_id", type = IdType.AUTO)
    private Integer areaId;

    private String areaName;

    private int priority;

}

3 service层

需要注意的是import的对象是什么（吃过这里的亏）

import com.alnex.myOwn.dao.Book;
import com.baomidou.mybatisplus.extension.service.IService;

public interface IBookService extends IService {
}

import org.springframework.stereotype.Service;

import com.alnex.myOwn.dao.Book;
import com.alnex.myOwn.mapper.BookMapper;
import com.alnex.myOwn.service.IBookService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

@Service
public class BookServerImpl extends ServiceImpl implements IBookService{
}

4 map包下

import com.baomidou.mybatisplus.core.mapper.BaseMapper;

public interface SuperMapper extends BaseMapper {
}

import java.util.List;

import org.apache.ibatis.annotations.Select;

import com.alnex.myOwn.dao.Book;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

public interface BookMapper extends BaseMapper {

    @Select("SELECT * FROM `tb_area`")
    List selectList();
}

5 controller包下

import javax.annotation.Resource;
import java.util.List;
import org.springframework.web.bind.annotation.*;

import com.alnex.myOwn.dao.Book;
import com.alnex.myOwn.service.IBookService;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import lombok.extern.slf4j.Slf4j;

@Slf4j
@RestController
@RequestMapping("/book")
public class IndexController {

    @Resource
    private IBookService bookServer;

    @GetMapping("/list/{pageNum}/{pageSize}")
    public Object index(@PathVariable("pageNum") int pageNum,@PathVariable("pageSize") int pageSize){

        System.out.println("pageNum = " + pageNum);
        System.out.println("pageSize = " + pageSize);

        log.info("----- baseMapper 自带分页 ------");
        Page pg = new Page<>(pageNum, pageSize);

        IPage bookIPage = bookServer.page(pg);
        log.info("总条数 ------> [{}]" , bookIPage.getTotal());
        log.info("当前页数 ------> [{}]" , bookIPage.getCurrent());
        log.info("当前每页显示数 ------> [{}]" , bookIPage.getSize());
        log.info("当前页数据 ------> [{}]" , bookIPage.getRecords());

        print(bookIPage.getRecords());

        log.info("----- Book 列表数据展示 ------");
        List list = bookServer.list();
        log.info("list 数据 ------> {[]} " + list);

        return bookIPage;
    }

    private  void print(List list) {
        if (!CollectionUtils.isEmpty(list)) {
            for (Book t : list) {
                log.info("Book 数据为 ----> [{}]",t);
                log.info("[{}]",t.getCreateTime());
                log.info("[{}]",t.getUpdateTime());
            }
        }
    }

    @GetMapping("/getOne/{areaId}")
    public Object getOne(@PathVariable("areaId") int areaId){

        System.out.println(areaId);

        //方法一
        Book other = bookServer.getById(areaId);
        log.info("book 数据为 ------> [{}]" , other);
        System.out.println();

        //方法二
        QueryWrapper queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("area_id",areaId);

        Book book = bookServer.getOne(queryWrapper);
        log.info("book1 数据为 ------> [{}]" , book);

        return book;
    }

    @PutMapping("/save")
    public Object save(@RequestBody Book book){
        return bookServer.save(book);
    }

    @DeleteMapping("/del/{areaId}")
    public Object del(@PathVariable("areaId") int areaId){

        boolean b;

        //方式一
        // b = bookServer.removeById(areaId);

        //方式二
        QueryWrapper queryWrapper  =new QueryWrapper<>();
        queryWrapper.eq("area_id",areaId);

        b = bookServer.remove(queryWrapper);

        return b;
    }

    @PutMapping("/update")
    public Object update(@RequestBody Book book){
        return bookServer.updateById(book);
    }

    //批量新增或者修改方法,判断ID是否存在，如果ID不存在执行新增，如果ID存在先执行查询语句，查询结果为空新增，否则修改。
    @PutMapping("/addMore")
    public Object addList(@RequestBody List list){
        return bookServer.saveOrUpdateBatch(list);
    }
}

6 config包下【重要】

在之前配置config 时只配置mybatisplus 的分页插件，发现在启动时一直报   Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required 的错误

附查询的相关资料：https://www.cnblogs.com/hawk0035/p/3337283.html?utm_source=tuicool

import javax.sql.DataSource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.type.JdbcType;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.baomidou.mybatisplus.core.MybatisConfiguration;
import com.baomidou.mybatisplus.core.MybatisXMLLanguageDriver;
import com.baomidou.mybatisplus.core.config.GlobalConfig;
import com.baomidou.mybatisplus.extension.incrementer.DB2KeyGenerator;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;


@Configuration
@MapperScan("com.alnex.myOwn.mapper")
public class MybatisPlusConfig {


    /**
     * mybatis-plus分页插件

     * 文档：http://mp.baomidou.com

     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource, GlobalConfig globalConfig) throws Exception {
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        sqlSessionFactory.setDataSource(dataSource);
        MybatisConfiguration configuration = new MybatisConfiguration();
        configuration.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
        configuration.setJdbcTypeForNull(JdbcType.NULL);
        configuration.setMapUnderscoreToCamelCase(true);
        sqlSessionFactory.setConfiguration(configuration);
        PaginationInterceptor pagination = new PaginationInterceptor();
        sqlSessionFactory.setPlugins(pagination);
        sqlSessionFactory.setGlobalConfig(globalConfig);
        return sqlSessionFactory.getObject();
    }

    @Bean
    public GlobalConfig globalConfig() {
        GlobalConfig config = new GlobalConfig();
        GlobalConfig.DbConfig dbConfig = new GlobalConfig.DbConfig();
        dbConfig.setKeyGenerator(new DB2KeyGenerator());
        config.setDbConfig(dbConfig);
        return config;
    }
}

以上就是mybatisplus的相关总结，如有问题，欢迎留言讨论~