Tlias教学管理系统项目实战

四层架构MVC

Controller（接收http请求）

public class EmpController {@Autowiredprivate EmpService empService;/*** 分页查询员工数据* @return*/@GetMappingpublic Result page(@RequestParam(defaultValue = "1") Integer page,@RequestParam(defaultValue = "10") Integer pageSize,String name, Integer gender,@DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,@DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end) {log.info("分页查询员工数据，参数：{},{},{},{},{},{}", page, pageSize, name, gender, begin, end);PageResult<Emp> pageResult = empService.page(page, pageSize, name, gender,  begin, end);return Result.success(pageResult);}
}

Service（业务逻辑处理）

public interface EmpService {PageResult<Emp> page(Integer page, Integer pageSize, String name, Integer gender, LocalDate begin, LocalDate end);
}

@Service
public class EmpServiceimpl implements EmpService {@Autowiredprivate EmpMapper empMapper;/*原始查询*/
//    @Override
//    public PageResult<Emp> page(Integer page, Integer pageSize) {
//        Long total = empMapper.count();
//        Integer start = (page - 1) * pageSize;
//        List<Emp> list = empMapper.page(start, pageSize);
//        return new PageResult<Emp>(total, list);
//    }@Overridepublic PageResult<Emp> page(Integer page, Integer pageSize, String name, Integer gender, LocalDate begin, LocalDate end) {PageHelper.startPage(page, pageSize);List<Emp> emplist = empMapper.list(name, gender, begin, end);Page<Emp> p = (Page<Emp>) emplist;return new PageResult<Emp>(p.getTotal(), p.getResult());}
}

Mapper（访问数据库）

@Mapper
public interface EmpMapper {/*** 原始查询*///    /**
//     * 查询总记录数
//     * @return
//     */
//    @Select("select count(*) from emp e left join dept d on e.dept_id = d.id")
//    public Long count();
//
//    /**
//     * 分页查询员工数据
//     * @param start
//     * @param pageSize
//     * @return
//     */
//    @Select("select e.*, d.name as deptName from emp e left join dept d on e.dept_id = d.id" +
//            "order by e.update_time desc limit #{start}, #{pageSize}")
//    public List<Emp> page(Integer start, Integer pageSize);@Select("select * from emp e left join dept d on e.dept_id = d.id")public Long count();//    @Select("select e.*, d.name as deptName from emp e left join dept d on e.dept_id = d.id " +
//            "order by e.update_time desc")public List<Emp> list(String name, Integer gender, LocalDate startDate, LocalDate endDate);