Java导出excel时合并同一列中相同内容的行思路详解

 public void expStatistics(String filePath,String campuscode) {
    try {
      WritableWorkbook wwb = Workbook.createWorkbook(new File(filePath));
      JxlFormatUtil Jfu = new JxlFormatUtil();
      WritableSheet ws = wwb.createSheet("房屋报表统计", 0);
      String[] tableHead = {"校区名称:20","房屋类型:30","房屋用途:30","使用面积(㎡):20"};
      for (int i = 0; i < tableHead.length; i++) {//每一列的标题样式
        ws.addCell(new Label(i, 0, tableHead[i].split(":")[0], JxlFormatUtil.wcHead));
        ws.setColumnView(i, Integer.valueOf(tableHead[i].split(":")[1]));
      }
      int col = 1;//从第1行开始
      //以下变量用来融合相同内容 的行
      int perCol = col;
      String perPurpose = "";//上一个用途类型
      String purpose = "";//当前用途类型
      int startMergeCol = 1;//要融合的第一行
      int endMergeCol = 0;//要融合的最后行
      boolean flag = true;//用来记录是否是第一次循环
      //根据搜索条件导出
      List<FcxtCampus> campusList = new ArrayList<FcxtCampus>();
      if(null != campuscode && !"".equals(campuscode)){
        campusList = campusdao.findCampusByCode(campuscode);
      }else {
        campusList =campusdao.findCampus();
      }
      for (FcxtCampus campus : campusList) {
        List<FcxtBuild> builds = builddao.statisticsBuilds(campus.getCampuscode());//获取所有房屋信息
        if(null != builds && builds.size() > 0){
          for (FcxtBuild build : builds) {
            int row = 0;//从第0列开始
            ws.addCell(new Label(row++, col, campus.getCampusname(), JxlFormatUtil.wcCenter));
            purpose = build.getUsefulpurpose();
            if(flag){//如果是第一次循环，将perPurpose初始化，以便后面的第一次判断
              perPurpose = purpose;
              flag = false;
            }
            ws.addCell(new Label(row++, col, FcxtBuild.BUILD_USEFULPURPOSE.get(build.getUsefulpurpose()), JxlFormatUtil.wcCenter));
            if(purpose.equals(perPurpose)){
              endMergeCol++;
            }else{//两者不相同时，融合之前相同的行
              ws.mergeCells(1, startMergeCol, 1, endMergeCol);
              startMergeCol = col;
              endMergeCol = startMergeCol;
              perPurpose = purpose;
            }
            ws.addCell(new Label(row++, col, FcxtBuild.BUILD_BUILDINGTYPE.get(build.getBuildingtype()), JxlFormatUtil.wcCenter));
            ws.addCell(new Label(row++, col, build.getBuildarea().toString(), JxlFormatUtil.wcCenter));
            col++;
          }
          ws.mergeCells(0, perCol, 0, col-1);
          perCol = col;
        }
      }
      wwb.write();
      wwb.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }