[JavaScript知识库]vue-element-admin-master 在线教育 -【2】后端讲师管理

哈喽！我是话里人，相信伙伴们通过上篇Blog的步骤，后端环境搭建已经完成，话不多说，那咱们书接上回~

介绍

• 在线教育，是一个B2C模式的职业技能在线教育系统，分为前台用户系统和后台运营平台。
  • B2C是指电子商务的一种模式，也是直接面向消费者销售产品和服务商业的零售模式。
  • Business-to-Consumer ：企业对客户

4.实现讲师列表接口

4.1 pojo

• 在zx-domain中创建实体类EduTeacher

package com.czxy.zx.domain;

import com.baomidou.mybatisplus.annotation.*;
import com.fasterxml.jackson.annotation.JsonFormat;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;

import java.util.Date;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Data//lombok注解
@ApiModel(value = "EduTeacher对象",description = "讲师")//swagger注解
public class EduTeacher {

    @TableId(value = "id",type = IdType.AUTO)//mybatis-plus的注解
    @ApiModelProperty(value = "讲师ID")//swagger注解
    private String id;
    @ApiModelProperty(value = "讲师姓名")
    private String name;
    @ApiModelProperty(value = "讲师资历,一句话说明讲师")
    private String intro;
    @ApiModelProperty(value = "讲师简介")
    private String career;
    @ApiModelProperty(value = "头衔 1高级讲师 2首席讲师")
    private Integer level;
    @ApiModelProperty(value = "讲师头像")
    private String avatar;
    @ApiModelProperty(value = "讲师排序")
    private Integer sort;
    @ApiModelProperty(value = "逻辑删除 1已删除， 0未删除")
    @TableField(value = "is_deleted",fill = FieldFill.INSERT)
    @TableLogic//逻辑删除
    private Integer isDeleted;
    @ApiModelProperty(value = "创建时间")
    @TableField(value = "gmt_create",fill = FieldFill.INSERT)
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")
    private Date gmtCreate;
    @ApiModelProperty(value = "更新时间")
    @TableField(value = "gmt_modified",fill = FieldFill.INSERT_UPDATE)
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")
    private Date gmtModified;

}

4.2 mapper

package com.czxy.zx.teacher.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.czxy.zx.domain.EduTeacher;
import org.apache.ibatis.annotations.Mapper;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Mapper
public interface EduTeacherMapper extends BaseMapper<EduTeacher> {
}

4.3 service

• 接口

package com.czxy.zx.teacher.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.czxy.zx.domain.EduTeacher;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
public interface EduTeacherService extends IService<EduTeacher> {
}

• 实现类

package com.czxy.zx.teacher.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.czxy.zx.domain.EduTeacher;
import com.czxy.zx.teacher.mapper.EduTeacherMapper;
import com.czxy.zx.teacher.service.EduTeacherService;
import org.springframework.stereotype.Service;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Service
public class EduTeacherServiceImpl extends ServiceImpl<EduTeacherMapper, EduTeacher> implements EduTeacherService {
}

4.4 Controller

TeacherController

package com.czxy.zx.teacher.controller;

import com.czxy.zx.domain.EduTeacher;
import com.czxy.zx.teacher.service.EduTeacherService;
import com.czxy.zx.vo.BaseResult;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;

/**
* @author txt
* @email tantintong9968@163.com
*/
@RestController
@RequestMapping("/teacher")
public class EduTeacherController {
   
   @Resource
   private EduTeacherService eduTeacherService;

   @GetMapping
   private BaseResult<List<EduTeacher>> getTeacherList(){
       List<EduTeacher> list = eduTeacherService.list(null);
       return BaseResult.ok("查询成功", list);
   }
}

4.5 拷贝配置类

4.5.1 拷贝配置类：config-MyBatisPlusConfig

package com.czxy.zx.teacher.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

// MyBatisPlus 分页插件
@Component
public class MyBatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return mybatisPlusInterceptor;
    }
}

4.5.2 拷贝配置类：config-MyBatisPlusConfig

package com.czxy.zx.teacher.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.*;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spi.service.contexts.SecurityContext;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

import java.util.ArrayList;
import java.util.List;

/**
 * Swagger2 配置类，
 * 访问路径：swagger-ui.html
 * 自动注册：
 *     位置：resources/META-INF/spring.factories
 *     内容：
 *        org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
 *          com.czxy.changgou4.config.Swagger2Configuration
 */
@Configuration
@EnableSwagger2
public class Swagger2ConfigurationV3 {

    @Bean
    public Docket createRestApi() {
        // 1 确定文档Swagger版本
        Docket docket = new Docket(DocumentationType.SWAGGER_2);
        // 2 设置 api基本信息
        docket.apiInfo(apiInfo());
        // 3 设置自定义加载路径
        docket = docket.select()
                .apis(RequestHandlerSelectors.basePackage("com.czxy"))
                .paths(PathSelectors.any())
                .build();
        //4 设置权限
        docket.securitySchemes(securitySchemes());
        docket.securityContexts(securityContexts());

        return docket;
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("API")
                .description("基于swagger接口文档")
                .contact(new Contact("梁桐","http://www.javaliang.com","liangtong@itcast.cn"))
                .version("1.0")
                .build();
    }

    private List<ApiKey> securitySchemes() {
        List<ApiKey> list = new ArrayList<>();
        // name 为参数名  keyname是页面传值显示的 keyname， name在swagger鉴权中使用
        list.add(new ApiKey("Authorization", "Authorization", "header"));
        return list;
    }

    private List<SecurityContext> securityContexts() {
        List<SecurityContext> list = new ArrayList<>();
        list.add(SecurityContext.builder()
                .securityReferences(defaultAuth())
                .forPaths(PathSelectors.regex("^(?!auth).*$"))
                .build());
        return list;
    }

    private List<SecurityReference> defaultAuth() {
        AuthorizationScope authorizationScope = new AuthorizationScope("global", "accessEverything");
        AuthorizationScope[] authorizationScopes = new AuthorizationScope[1];
        authorizationScopes[0] = authorizationScope;
        List<SecurityReference> list = new ArrayList();
        list.add(new SecurityReference("Authorization", authorizationScopes));
        return list;
    }

}

4.6 处理Swagger接口

• 修改controller

package com.czxy.zx.teacher.controller;

import com.czxy.zx.domain.EduTeacher;
import com.czxy.zx.teacher.service.EduTeacherService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@RestController
@RequestMapping("/teacher")
@Api(tags = "老师接口", description = "老师接口描述，完成增删改查操作")
public class EduTeacherController {

    @Resource
    private EduTeacherService eduTeacherService;

    @ApiOperation(value = "查询所有老师")
    @GetMapping
    private BaseResult<List<EduTeacher>> getTeacherList(){
        List<EduTeacher> list = eduTeacherService.list(null);
        return BaseResult.ok("查询成功", list);
    }
}

4.7 测试

http://localhost:9000/swagger-ui.html
http://localhost:10010/teacher-service/swagger-ui.html

5.讲师逻辑删除

5.1 在Controller中添加删除方法

    @ApiOperation(value = "根据ID删除讲师")
    @ApiImplicitParams(value = {
//            @ApiImplicitParam(name = "id", value = "讲师ID", required = true,paramType = "path")//方式一
    })
    @DeleteMapping("/{id}")
    public boolean removeById(
            @ApiParam(name = "id", value = "讲师ID", required = true)//方式二
            @PathVariable("id") String id){
        return eduTeacherService.removeById(id);
    }

5.2 在EduTeacher.java文件中

@ApiModelProperty(value = "逻辑删除 1（true）已删除， 0（false）未删除")
@TableLogic
@TableField(fill = FieldFill.INSERT, value = "is_deleted")
private Boolean isDeleted;

5.3 完善：配置Handler

• 创建 com.czxy.zx.teacher.handler.TeacherMetaObjectHandler.java

package com.czxy.zx.teacher.handler;

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Component
public class TeacherMetaObjectHandler implements MetaObjectHandler {
    @Override
    public void insertFill(MetaObject metaObject) {
        // 添加时，填充的内容
        // this.setFieldValByName("字段名", 字段值 , metaObject);
        this.setFieldValByName("isDeleted",0 , metaObject);

    }

    @Override
    public void updateFill(MetaObject metaObject) {
        // 修改时，填充的内容

    }
}

5.4 完善：配置application.yaml文件

• 配置指定删除和不删除的状态

  

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  global-config:
    db-config:
      logic-delete-value: 1
      logic-not-delete-value: 0

5.5 讲师逻辑删除测试

ok

6.分页和条件查询

6.1 基本查询

6.1.1 创建 vo

package com.czxy.zx.teacher.vo;

import lombok.Data;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Data
public class TeacherVo {

}

6.1.2 controller

@ApiOperation(value = "所有老师：条件 + 分页")
    @ApiImplicitParams({
            @ApiImplicitParam(name = "size",value = "每页个数",required = true,paramType = "path", dataType = "int"),
            @ApiImplicitParam(name = "current",value = "当前页",required = true,paramType = "path", dataType = "int")
    })
    @PostMapping("/condition/{size}/{current}")
    public BaseResult<Page<EduTeacher>> condition(
            @PathVariable("size") Integer size,
            @PathVariable("current") Integer current,
            @RequestBody TeacherVo teacherVo
            ){
        Page<EduTeacher> page = eduTeacherService.condition(size,current,teacherVo);

        return BaseResult.ok("查询成功", page);
    }

6.1.3 service

• 接口

  package com.czxy.zx.teacher.service;
  
  import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
  import com.baomidou.mybatisplus.extension.service.IService;
  import com.czxy.zx.domain.EduTeacher;
  import com.czxy.zx.teacher.vo.TeacherVo;
  
  /**
   * @author txt
   * @email tantintong9968@163.com
   */
  public interface EduTeacherService extends IService<EduTeacher> {
      /**
       * 条件分页查询
       * @param size
       * @param current
       * @param teacherVo
       * @return
       */
      Page<EduTeacher> condition(Integer size, Integer current, TeacherVo teacherVo);
  }
  
  

• 实现类

  package com.czxy.zx.teacher.service.impl;
  
  import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
  import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
  import com.czxy.zx.domain.EduTeacher;
  import com.czxy.zx.teacher.mapper.EduTeacherMapper;
  import com.czxy.zx.teacher.service.EduTeacherService;
  import com.czxy.zx.teacher.vo.TeacherVo;
  import org.springframework.stereotype.Service;
  
  
   /**
     * @author txt
     * @email tantintong9968@163.com
     */
  @Service
  public class EduTeacherServiceImpl extends ServiceImpl<EduTeacherMapper, EduTeacher> implements EduTeacherService {
      @Override
      public Page<EduTeacher> condition(Integer size, Integer current, TeacherVo teacherVo) {
          return null;
      }
  }
  
  

6.2 分页

• 修改service，完成分页查询

package com.czxy.zx.teacher.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.czxy.zx.domain.EduTeacher;
import com.czxy.zx.teacher.mapper.EduTeacherMapper;
import com.czxy.zx.teacher.service.EduTeacherService;
import com.czxy.zx.teacher.vo.TeacherVo;
import org.springframework.stereotype.Service;

/**
 * @author txt
 * @email tantintong9968@163.com
 */
@Service
public class EduTeacherServiceImpl extends ServiceImpl<EduTeacherMapper, EduTeacher> implements EduTeacherService {
    @Override
    public Page<EduTeacher> condition(Integer size, Integer current, TeacherVo teacherVo) {
        //1 条件查询
        QueryWrapper<EduTeacher> queryWrapper = new QueryWrapper<>();

        //2 分页条件
        Page<EduTeacher> page = new Page<>(current,size);

        //3 查询
        this.baseMapper.selectPage(page, queryWrapper);

        //4 关联查询

        //5 返回
        return page;
    }
}

6.3 条件查询

• 需求：

  • 根据讲师姓名模糊查询
  • 根据讲师头衔精准查询
  • 根据时间范围查询（开始时间、结束时间）

• 完善vo

  package com.czxy.zx.teacher.vo;
  
  import io.swagger.annotations.ApiModel;
  import io.swagger.annotations.ApiModelProperty;
  import lombok.Data;
  
   /**
     * @author txt
     * @email tantintong9968@163.com
     */
  @Data
  @ApiModel(value = "封装了Teacher条件查询的参数")
  public class TeacherVo {
      @ApiModelProperty(value = "讲师姓名，模糊查询")
      private String name;
      @ApiModelProperty(value = "讲师头衔：1 高级讲师  2 首席讲师")
      private String level;
      @ApiModelProperty(value = "查询开始时间",example = "2020-02-01 10:12:30")
      private String beginDate;
      @ApiModelProperty(value = "查询截止时间",example = "2020-02-01 10:12:30")
      private String endDate;
  }
  
  

• 完善service

  package com.czxy.zx.teacher.service.impl;
  
  import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
  import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
  import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
  import com.czxy.zx.domain.EduTeacher;
  import com.czxy.zx.teacher.mapper.EduTeacherMapper;
  import com.czxy.zx.teacher.service.EduTeacherService;
  import com.czxy.zx.teacher.vo.TeacherVo;
  import org.apache.commons.lang.StringUtils;
  import org.springframework.stereotype.Service;
  
  /**
   * @author txt
   * @email tantintong9968@163.com
   */
  @Service
  public class EduTeacherServiceImpl extends ServiceImpl<EduTeacherMapper, EduTeacher> implements EduTeacherService {
      @Override
      public Page<EduTeacher> condition(Integer size, Integer current, TeacherVo teacherVo) {
          //1 条件查询
          QueryWrapper<EduTeacher> queryWrapper = new QueryWrapper<>();
          queryWrapper.like(StringUtils.isNotBlank(teacherVo.getName()), "name", teacherVo.getName());
          queryWrapper.eq(StringUtils.isNotBlank(teacherVo.getLevel()), "level", teacherVo.getLevel());
          queryWrapper.ge(StringUtils.isNotBlank(teacherVo.getBeginDate()), "gmt_create", teacherVo.getBeginDate()+ " 00:00:00" );
          queryWrapper.le(StringUtils.isNotBlank(teacherVo.getEndDate()), "gmt_create", teacherVo.getEndDate() + " 23:59:59");
  
          //2 分页条件
          Page<EduTeacher> page = new Page<>(current,size);
  
          //3 查询
          this.baseMapper.selectPage(page, queryWrapper);
  
          //4 关联查询
  
          //5 返回
          return page;
      }
  }
  
  

6.4 测试

ok

7.讲师新增和修改

7.1 新增

在Controller中编写代码

    @ApiOperation(value = "新增讲师")
    @PostMapping
    public BaseResult save(
            @ApiParam(name = "teacher", value = "讲师对象", required = true)
            @RequestBody EduTeacher teacher){

        boolean save = eduTeacherService.save(teacher);
        if(save) {
            return BaseResult.ok("添加成功");
        }
        return BaseResult.error("添加失败");
    }

• 测试数据

{
  "avatar": "https://czxy-lt.oss-cn-shanghai.aliyuncs.com/avatar/449972ccd28a41d6a8317c97a9c2319e.png",
  "career": "讲师简介",
  "gmtCreate": "2022-06-27 08:16:32",
  "gmtModified": "2022-06-27 08:16:32",
  "intro": "讲师资历",
  "level": 1,
  "name": "张三",
  "sort": 0
}

7.2 根据id查询

    @ApiOperation(value = "根据ID查询讲师")
    @GetMapping("{id}")
    public BaseResult getById(
            @ApiParam(name = "id", value = "讲师ID", required = true)
            @PathVariable String id){

        EduTeacher teacher = eduTeacherService.getById(id);
        return BaseResult.ok("查询成功", teacher);
    }

7.3 根据id查询 + 通过id修改

• 通过id查询

  /**
   * 通过id查询详情
   * @param teacherId
   * @return
   */
  @GetMapping("/{teacherId}")
  public BaseResult<EduTeacher> findById(@PathVariable("teacherId") Integer teacherId ) {
      // 查询
      EduTeacher eduTeacher = eduTeacherService.getById(teacherId);
      if(eduTeacher != null) {
          // 返回
          return BaseResult.ok("查询成功", eduTeacher);
      }
      return BaseResult.error("查询失败");
  }
  

• 通过id修改

      @ApiOperation(value = "根据ID修改讲师")
      @PutMapping
      public BaseResult updateById(
              @ApiParam(name = "teacher", value = "讲师对象", required = true)
              @RequestBody EduTeacher teacher){
  
          boolean update = eduTeacherService.updateById(teacher);
          if(update) {
              return BaseResult.ok("更新成功");
          }
          return BaseResult.error("更新失败");
      }
  

7.4 批量删除

	/**
     * 批量删除
     * @return
     */
    @PostMapping("/batchDelete")
    public BaseResult batchDelete(@RequestBody List<Integer> ids) {
        boolean result = eduTeacherService.removeByIds(ids);
        if(result) {
            return BaseResult.ok("批量删除成功");
        }
        return  BaseResult.error("批量删除失败");
    }

7.5 修改处理类：自动填充

package com.czxy.zx.teacher.handler;

import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;

import java.util.Date;

  /**
   * @author txt
   * @email tantintong9968@163.com
   */
@Component
public class TeacherMetaObjectHandler implements MetaObjectHandler {
    @Override
    public void insertFill(MetaObject metaObject) {
        // 给javabean默认值
        // 1 逻辑删除的默认值
        this.setFieldValByName("isDeleted", 0 , metaObject);
        // 2 创建、修改时间
        this.setFieldValByName("gmtCreate", new Date(), metaObject);
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        // 2 修改时间
        this.setFieldValByName("gmtModified", new Date(), metaObject);
    }
}

8.统一异常处理

8.1 测试系统对错误的响应

• 在更新操作中，应该输入{}填写更新数据，如果填写成[]，程序将抛出异常。

  

  

8.2 全局异常处理

• 我们想让异常结果也统一，并且在集中的地方处理系统的异常信息，那么需要统一异常处理。

• spring mvc 提供 @ControllerAdvice就可以完成此需求。

  

• @ControllerAdvice 是对Controller进行增强的注解，主要作用有三个：

  1. 全局异常处理【重点】

  2. 全局数据绑定

  3. 全局数据预处理

• zx-common中创建统一异常处理类：

  

package com.czxy.zx.exception;

import com.czxy.zx.vo.BaseResult;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

  /**
   * @author txt
   * @email tantintong9968@163.com
   */
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)//拦截什么异常
    @ResponseBody
    public BaseResult error(Exception e){
        e.printStackTrace();
        return BaseResult.error("系统错误");
    }
}

• 注意：启动类的位置

  • 启动类必须放在 com.czxy.zx包下面才可以加载到com.czxy.zx.exception包下面的内容
  • 如果放在com.czxy.zx.teacher下面，将无法加载到com.czxy.zx.exception包下面的内容

  

• 测试，返回统一错误结果

8.3 特殊异常配置

如果是除数为0的异常；那么需要如下配置，精确匹配异常：

package com.czxy.zx.exception;

import com.czxy.zx.vo.BaseResult;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;

  /**
   * @author txt
   * @email tantintong9968@163.com
   */
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)//拦截什么异常
    @ResponseBody
    public BaseResult error(Exception e){
        e.printStackTrace();
        return BaseResult.error("系统错误");
    }

    @ExceptionHandler(ArithmeticException.class)
    @ResponseBody
    public BaseResult error(ArithmeticException e){
        e.printStackTrace();
        return BaseResult.error("除数不能为0");
    }
}

8.4 自定义异常

8.4.1 EduException通用异常类

• 在zx-common中创建Exception的异常类

package com.czxy.zx.exception;

import io.swagger.annotations.ApiModel;

  /**
   * @author txt
   * @email tantintong9968@163.com
   */
@ApiModel(value = "自定义异常")
public class EduException extends RuntimeException {

    public EduException(String message) {
        super(message);
    }

    public EduException(String message, Throwable cause) {
        super(message, cause);
    }

    public EduException(Throwable cause) {
        super(cause);
    }

    protected EduException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
}

8.4.2 创建捕获自定义异常类

• 在 GlobalExceptionHandler类中添加自定义处理方法

    @ExceptionHandler(EduException.class)
    @ResponseBody
    public BaseResult error(EduException e){
        e.printStackTrace();
        if(e.getMessage() == null) {
            return BaseResult.error("空指针异常");
        }
        return BaseResult.error(e.getMessage());
    }

• 测试：在业务中需要的位置抛出EduException，举例子在查询列表中出错：

    @ApiOperation(value = "查询所有老师")
    @GetMapping
    private BaseResult<List<EduTeacher>> getTeacherList(){
        List<EduTeacher> list = eduTeacherService.list(null);
        //测试自定义异常
        if(list.size() > 0) {
            throw new EduException("数据异常");
        }
        return BaseResult.ok("查询成功", list);
    }

8.4.3 异常工具类

• 编写 ExceptionUtils 类，方便异常的抛出

  

  package com.czxy.zx.exception;
  
  /**
   * @author txt
   * @email tantintong9968@163.com
   */
  public class ExceptionUtils {
      /**
       * 抛出异常
       * @param message
       */
      public static void cast(String message) {
          throw new EduException(message);
      }
  }
  
  

• 测试：

      @ApiOperation(value = "查询所有老师")
      @GetMapping
      private BaseResult<List<EduTeacher>> getTeacherList(){
          List<EduTeacher> list = eduTeacherService.list(null);
          //测试自定义异常
          if(list.size() > 0) {
              //throw new EduException("数据异常");
              ExceptionUtils.cast("数据异常");
          }
          return BaseResult.ok("查询成功", list);
      }
  

9.附：创建MP代码生成器

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-engine-core</artifactId>
            <version>2.0</version>
        </dependency>

在test/java目录下创建包com.zx.edu，创建代码生成器：CodeGenerator.java

package com.zx;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.rules.DateType;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import org.junit.Test;

public class CodeGenerator {
    @Test
    public void run() {
        // 1、创建代码生成器
        AutoGenerator mpg = new AutoGenerator();
        // 2、全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        //有的电脑系统，如果代码发现生成有问题，projectPath直接写成项目名称
        //gc.setOutputDir("edu_eduservice" + "/src/main/java");
        gc.setOutputDir(projectPath + "/src/main/java");
        gc.setAuthor("lt");
        gc.setOpen(false); //生成后是否打开资源管理器

        gc.setFileOverride(false); //重新生成时文件是否覆盖
        //IUserServcie
        gc.setServiceName("%sService");    //去掉Service接口的首字母I
        gc.setIdType(IdType.ID_WORKER_STR); //主键策略
        gc.setDateType(DateType.ONLY_DATE);//定义生成的实体类中日期类型
        gc.setSwagger2(true);//开启Swagger2模式
        mpg.setGlobalConfig(gc);
        // 3、数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://localhost:3306/zx_edu_teacher");
        dsc.setDriverName("com.mysql.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("1234");
        dsc.setDbType(DbType.MYSQL);
        mpg.setDataSource(dsc);

        // 4、包配置
        PackageConfig pc = new PackageConfig();
        pc.setModuleName("teacher"); //模块名
        pc.setParent("com.zx");
        pc.setController("controller");
        pc.setEntity("entity");
        pc.setService("service");
        pc.setMapper("mapper");
        mpg.setPackageInfo(pc);
        // 5、策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setInclude("edu_teacher");//表名称
strategy.setNaming(NamingStrategy.underline_to_camel);//数据库表映射到实体的命名策略
        strategy.setTablePrefix(pc.getModuleName() + "_"); //生成实体时去掉表前缀

        strategy.setColumnNaming(NamingStrategy.underline_to_camel);//数据库表字段映射到实体的命名策略
        strategy.setEntityLombokModel(true); // lombok 模型 @Accessors(chain = true) setter链式操作
        strategy.setRestControllerStyle(true); //restful api风格控制器
        strategy.setControllerMappingHyphenStyle(true); //url中驼峰转连字符
        mpg.setStrategy(strategy);
        // 6、执行
        mpg.execute();
    }
}

执行代码生成器方法

说明：

XxxServiceImpl 继承了 ServiceImpl 类，并且MP为我们注入了 XxxMapper

这样可以使用 service 层默认为我们提供的很多方法，当然也可以调用我们自己在 dao 层编写的方法。

end

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