一、2018年12月1日23:38:18
dao层接口
public interface AreaDao {
    /**
     * 列出区域列表List
     * @return List<Area>
     */
    public List<Area> queryArea();
}

mapper dao层接口的实现
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.imooc.dao.AreaDao">
    <!--查询出的结果转化为Area对象的列表，每一个实体类-->
    <select id="queryArea" resultType="com.imooc.entity.Area">
        SELECT area_id,area_name,priority,create_time,last_edit_time
        FROM tb_area
        ORDER BY priority DESC
    </select>
</mapper>

service层接口
public interface AreaService {
    public List<Area> getAreaList();
}

service层接口的实现
@Service
public class AreaServiceImpl implements AreaService {
    @Autowired
    private AreaDao areaDao;
    public List<Area> getAreaList() {
        return areaDao.queryArea();
    }
}

controller层
@Controller
@RequestMapping("/superadmin")
public class AreaController {
    @Autowired
    private AreaService areaService;
    @RequestMapping(value = "/listarea",method = RequestMethod.GET)
    @ResponseBody
    private Map<String,Object> listArea(){
        Map<String,Object> modelMap = new HashMap<String,Object>();
        List<Area> list = new ArrayList<Area>();
        try{
            list = areaService.getAreaList();
            //前端使用的是easyUI
            modelMap.put("rows",list);
            modelMap.put("total",list.size());
        }catch ( Exception e ){
            e.printStackTrace();
            modelMap.put("success",true);
            modelMap.put("errMsg",e.toString());
        }
        return modelMap;
    }
}

测试
//http://localhost:8080/money/superadmin/listarea
返回json格式的数据库数据
{"total":2,
"rows":[{"areaId":2,"areaName":"西苑","priority":2,"createTime":null,"lastEditTime":null},
        {"areaId":1,"areaName":"东苑","priority":1,"createTime":null,"lastEditTime":null}]}