上个小节我们看明白了复杂的SQL语句是怎么演进出来的，持久层的代码我们也写完了，本小节我们去把业务层也Web层的代码给写一下。

一、编写业务层代码

创建MeetingService.java接口，然后定义抽象方法。

public interface MeetingService {
    public PageUtils searchOfflineMeetingByPage(HashMap param);
}

创建MeetingServiceImpl.java类，实现抽象方法。这里需要额外注意

@Service
@Slf4j
public class MeetingServiceImpl implements MeetingService {
    @Autowired
    private TbMeetingDao meetingDao;
    
    @Override
    public PageUtils searchOfflineMeetingByPage(HashMap param) {
        ArrayList<HashMap> list = meetingDao.searchOfflineMeetingByPage(param);
        long count = meetingDao.searchOfflineMeetingCount(param);
        int start = (Integer) param.get("start");
        int length = (Integer) param.get("length");
        //把meeting字段转换成JSON数组对象
        for (HashMap map : list) {
            String meeting = (String) map.get("meeting");
            //如果Meeting是有效的字符串，就转换成JSON数组对象
            if (meeting != null && meeting.length() > 0) {
                map.replace("meeting", JSONUtil.parseArray(meeting));
            }
        }
        PageUtils pageUtils = new PageUtils(list, count, start, length);
        return pageUtils;
    }
}

二、编写Web层代码

创建SearchOfflineMeetingByPageForm.java类，封装Ajax提交的数据。

@Data
@Schema(description = "查询线下会议分页表单")
public class SearchOfflineMeetingByPageForm {
    @Pattern(regexp = "^((((1[6-9]|[2-9]\\d)\\d{2})-(0?[13578]|1[02])-(0?[1-9]|[12]\\d|3[01]))|(((1[6-9]|[2-9]\\d)\\d{2})-(0?[13456789]|1[012])-(0?[1-9]|[12]\\d|30))|(((1[6-9]|[2-9]\\d)\\d{2})-0?2-(0?[1-9]|1\\d|2[0-8]))|(((1[6-9]|[2-9]\\d)(0[48]|[2468][048]|[13579][26])|((16|[2468][048]|[3579][26])00))-0?2-29-))$", message = "date内容不能为空")
    @Schema(description = "日期")
    private String date;

    @NotNull(message = "mold不能空")
    @Pattern(regexp = "^全部会议$|^我的会议$", message = "mold内容错误")
    @Schema(description = "模式")
    private String mold;

    @NotNull(message = "page不能为空")
    @Min(value = 1, message = "page不能小于1")
    @Schema(description = "页数")
    private Integer page;

    @NotNull(message = "length不能为空")
    @Range(min = 10, max = 50, message = "length必须在10~50之间")
    @Schema(description = "每页记录数")
    private Integer length;
}

创建MeetingController.java类，定义Web方法，然后用Swagger程序测试一下。

@RestController
@RequestMapping("/meeting")
@Tag(name = "MeetingController", description = "会议Web接口")
public class MeetingController {
    @Autowired
    private MeetingService meetingService;
    
    @PostMapping("/searchOfflineMeetingByPage")
    @Operation(summary = "查询线下会议分页数据")
    @SaCheckLogin
    public R searchOfflineMeetingByPage(@Valid @RequestBody SearchOfflineMeetingByPageForm form) {
        int page = form.getPage();
        int length = form.getLength();
        int start = (page - 1) * length;
        HashMap param = new HashMap() {{
            put("date", form.getDate());
            put("mold", form.getMold());
            put("userId", StpUtil.getLoginId());
            put("start", start);
            put("length", length);
        }};
        PageUtils pageUtils = meetingService.searchOfflineMeetingByPage(param);
        return R.ok().put("page", pageUtils);
    }
}