day02---分页和条件查询接口开发(06)

一、分页

1、EduConfig 中配置分页插件

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

2、分页Controller方法

EduTeacherController中添加分页方法

@ApiOperation(value = "分页讲师列表")
    @GetMapping("{page}/{limit}")
    public R pageQuery(
            @ApiParam(name = "page", value = "当前页码", required = true)
            @PathVariable Long page,
            @ApiParam(name = "limit", value = "每页记录数", required = true)
            @PathVariable Long limit,
            @ApiParam(name = "teacherQuery", value = "查询对象", required = false)
                    TeacherQuery teacherQuery){
        Page<EduTeacher> pageParam = new Page<>(page, limit);
        eduTeacherService.pageQuery(pageParam, teacherQuery);
        List<EduTeacher> records = pageParam.getRecords();
        long total = pageParam.getTotal();
        /*//返回数据
        Map<String,Object> map = new HashMap<>();
        map.put("total", total);
        map.put("rows", records);*/
       return  R.ok().data("total", total).data("rows", records);
    }

3、Swagger中测试

http://localhost:8001/swagger-ui.html

二、条件查询

根据讲师名称name，讲师头衔level、讲师入驻时间gmt_create（时间段）查询

1、创建查询对象

创建com.atguigu.eduservice.query包，创建TeacherQuery.java查询对象

package com.atguigu.eduservice.query;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import java.io.Serializable;
@ApiModel(value = "Teacher查询对象", description = "讲师查询对象封装")
@Data
public class TeacherQuery implements Serializable {
    private static final long serialVersionUID = 1L;
    @ApiModelProperty(value = "教师名称,模糊查询")
    private String name;
    @ApiModelProperty(value = "头衔 1高级讲师 2首席讲师")
    private Integer level;
    @ApiModelProperty(value = "查询开始时间", example = "2019-01-01 10:10:10")
    private String begin;//注意，这里使用的是String类型，前端传过来的数据无需进行类型转换
    @ApiModelProperty(value = "查询结束时间", example = "2019-12-01 10:10:10")
    private String end;
}

2、service

（1）编写接口

package com.atguigu.eduservice.service;
import com.atguigu.eduservice.entity.EduTeacher;
import com.atguigu.eduservice.query.TeacherQuery;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.IService;
public interface EduTeacherService extends IService<EduTeacher> {
    void pageQuery(Page<EduTeacher> pageParam, TeacherQuery teacherQuery);
}

（2）实现接口

package com.atguigu.eduservice.service.impl;
import com.alibaba.nacos.client.naming.utils.StringUtils;
import com.atguigu.eduservice.entity.EduTeacher;
import com.atguigu.eduservice.mapper.EduTeacherMapper;
import com.atguigu.eduservice.query.TeacherQuery;
import com.atguigu.eduservice.service.EduTeacherService;
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 org.springframework.stereotype.Service;
import java.util.Collection;
@Service
public class EduTeacherServiceImpl extends ServiceImpl<EduTeacherMapper, EduTeacher> implements EduTeacherService {
    @Override
    public void pageQuery(Page<EduTeacher> pageParam, TeacherQuery teacherQuery) {
        QueryWrapper<EduTeacher> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByAsc("sort");
        if (teacherQuery == null){
            baseMapper.selectPage(pageParam, queryWrapper);
            return;
        }
        String name = teacherQuery.getName();
        Integer level = teacherQuery.getLevel();
        String begin = teacherQuery.getBegin();
        String end = teacherQuery.getEnd();
        if (!StringUtils.isEmpty(name)) {
            queryWrapper.like("name", name);
        }
        if (!StringUtils.isEmpty(String.valueOf(level)) ) {
            queryWrapper.eq("level", level);
        }
        if (!StringUtils.isEmpty(begin)) {
            queryWrapper.ge("gmt_create", begin);
        }
        if (!StringUtils.isEmpty(end)) {
            queryWrapper.le("gmt_create", end);
        }
        baseMapper.selectPage(pageParam, queryWrapper);
    }
}

3、controller

在EduTeacherController中添加getTeacherPageVo方法实现带条件分页查询讲师列表：

增加参数TeacherQuery teacherQuery，非必选

@ApiOperation(value = "带条件分页查询讲师列表")
    @PostMapping("getTeacherPageVo/{current}/{limit}")
    public R getTeacherPageVo(@PathVariable Long current,
                              @PathVariable Long limit,
                              @RequestBody TeacherQuery teacherQuery){
        //@RequestBody 必须使用PostMapping
        //@RequestBody 可以把json对象转化成vo
        //1创建page对象
        Page<EduTeacher> page = new Page<>(current,limit);
        //1.5从teacherQuery获取值拼接条件
        String name = teacherQuery.getName();
        Integer level = teacherQuery.getLevel();
        String begin = teacherQuery.getBegin();
        String end = teacherQuery.getEnd();
        QueryWrapper<EduTeacher> queryWrapper = new QueryWrapper<>();
        if(!StringUtils.isEmpty(name)){
            queryWrapper.like("name",name);
        }
        if(!StringUtils.isEmpty(String.valueOf(level))){
            queryWrapper.eq("level",level);
        }
        if(!StringUtils.isEmpty(begin)){
            queryWrapper.ge("gmt_create",begin);
        }
        if(!StringUtils.isEmpty(end)){
            queryWrapper.le("gmt_create",end);
        }
        //2调用方法获得数据
        eduTeacherService.page(page,queryWrapper);
        //3从page里获取数据
        long total = page.getTotal();
        List<EduTeacher> records = page.getRecords();
        //4返回数据
//        Map<String,Object> map = new HashMap<>();
//        map.put("total",total);
//        map.put("items",records);
//        return R.ok().data(map);
        return R.ok().data("total",total).data("items",records);
    }

4、Swagger中测试

http://localhost:8001/swagger-ui.html