EasyExcel核心实战之Excel合并单元格,在线编辑与导出全攻略

// POI 手动合并的逻辑示例
CellRangeAddress region = new CellRangeAddress(0, 0, 0, 3);
sheet.addMergedRegion(region);

@Data
public class EmployeeReportDTO {
    
    @ExcelProperty(value = "部门", mergeColumn = true)   // 相同部门自动合并
    private String department;
    
    @ExcelProperty("姓名")
    private String name;
    
    @ExcelProperty("工号")
    private String employeeId;
    
    @ExcelProperty("入职日期")
    private String hireDate;
}

EasyExcel.write(response.getOutputStream(), EmployeeReportDTO.class)
    .sheet("员工报表")
    .doWrite(dataList);

import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;

import java.util.HashMap;
import java.util.Map;

public class CustomMergeStrategy implements CellWriteHandler {

    private int[] mergeColumnIndex;          // 需要合并的列索引数组
    private int mergeRowIndex;                // 起始合并的行号
    private Map<String, Integer> mergeCache;  // 合并缓存

    // 构造函数：指定需要合并的列和起始行
    public CustomMergeStrategy(int[] mergeColumnIndex, int mergeRowIndex) {
        this.mergeColumnIndex = mergeColumnIndex;
        this.mergeRowIndex = mergeRowIndex;
        this.mergeCache = new HashMap<>();
    }

    @Override
    public void afterCellDispose(WriteSheetHolder writeSheetHolder, 
                                  WriteTableHolder writeTableHolder,
                                  List<Cell> cellList, Cell cell, 
                                  int relativeRowIndex, boolean isHead) {
        // 表头不合并
        if (isHead) return;
        
        int curRowIndex = cell.getRowIndex();
        int curColIndex = cell.getColumnIndex();
        
        // 只处理需要合并的列
        boolean needMerge = false;
        for (int index : mergeColumnIndex) {
            if (curColIndex == index) {
                needMerge = true;
                break;
            }
        }
        if (!needMerge) return;
        
        // 获取当前单元格的值
        String curValue = getCellValue(cell);
        if (curValue == null || curValue.isEmpty()) return;
        
        // 生成唯一键：列索引 + 行号
        String cacheKey = curColIndex + "_" + curValue;
        Integer startRow = mergeCache.get(cacheKey);
        
        if (startRow == null) {
            // 第一次出现该值，记录起始行
            mergeCache.put(cacheKey, curRowIndex);
        } else {
            // 第二次及以后出现，说明这是一个需要合并的区域
            // 如果当前行已经是最后一行，或下一行的值不同，则执行合并
            boolean needMergeNow = isLastRow(writeSheetHolder, curRowIndex) 
                                    || !curValue.equals(getNextRowValue(writeSheetHolder, curRowIndex, curColIndex));
            if (needMergeNow && startRow != curRowIndex) {
                Sheet sheet = writeSheetHolder.getSheet();
                CellRangeAddress range = new CellRangeAddress(startRow, curRowIndex, curColIndex, curColIndex);
                sheet.addMergedRegion(range);
                // 合并后移除缓存，避免重复合并
                mergeCache.remove(cacheKey);
            }
        }
    }
    
    private String getCellValue(Cell cell) {
        if (cell == null) return "";
        switch (cell.getCellType()) {
            case STRING: return cell.getStringCellValue();
            case NUMERIC: return String.valueOf(cell.getNumericCellValue());
            default: return "";
        }
    }
    
    private boolean isLastRow(WriteSheetHolder writeSheetHolder, int curRowIndex) {
        return curRowIndex == writeSheetHolder.getSheet().getLastRowNum();
    }
    
    private String getNextRowValue(WriteSheetHolder writeSheetHolder, int curRowIndex, int curColIndex) {
        Sheet sheet = writeSheetHolder.getSheet();
        if (curRowIndex + 1 > sheet.getLastRowNum()) return null;
        Cell nextCell = sheet.getRow(curRowIndex + 1).getCell(curColIndex);
        return nextCell == null ? null : getCellValue(nextCell);
    }
}

private void exportWithMerge(HttpServletResponse response, List<YourDTO> dataList) {
    try {
        EasyExcel.write(response.getOutputStream(), YourDTO.class)
            .registerWriteHandler(new CustomMergeStrategy(
                new int[]{0, 1},   // 合并第1列（部门）和第2列（职位）
                1                  // 从第1行开始合并（跳过表头）
            ))
            .sheet("报表")
            .doWrite(dataList);
    } catch (IOException e) {
        throw new RuntimeException("导出失败", e);
    }
}

<template>
  <div class="excel-container">
    <button @click="exportToBackend">保存并导出</button>
    <div id="luckysheet" style="width:100%; height:600px;"></div>
  </div>
</template>
<script setup>
import { onMounted, ref } from 'vue';
import axios from 'axios';
const sheetData = ref(null);
onMounted(() => {
  // 初始化 Luckysheet
  luckysheet.create({
    container: 'luckysheet',
    lang: 'zh',
    data: [{
      name: 'Sheet1',
      status: '1',
      row: 100,
      column: 20,
      celldata: []  // 可从后端加载已有数据
    }]
  });
  // 监听数据变化
  luckysheet.on('dataChange', () => {
    sheetData.value = luckysheet.getSheetData();
  });
});
const exportToBackend = async () => {
  const currentData = luckysheet.getAllSheets();
  // 将 Luckysheet 的数据格式转换为后端可识别的 JSON
  const exportData = {
    sheets: currentData,
    fileName: '在线编辑报表.xlsx'
  };
  const response = await axios.post('/api/export/edit-excel', exportData, {
    responseType: 'blob'  // 重要：接收文件流
  });
  // 下载文件
  const url = window.URL.createObjectURL(new Blob([response.data]));
  const link = document.createElement('a');
  link.href = url;
  link.setAttribute('download', exportData.fileName);
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  window.URL.revokeObjectURL(url);
};
</script>

@RestController
@RequestMapping("/api/export")
public class ExcelExportController {

    @PostMapping("/edit-excel")
    public void exportEditedExcel(@RequestBody ExcelEditRequest request, 
                                   HttpServletResponse response) throws IOException {
        // 1. 获取前端传来的编辑后数据
        List<Map<String, Object>> editedData = request.getData();
        
        // 2. 使用 EasyExcel 写入
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        String fileName = URLEncoder.encode(request.getFileName(), "UTF-8").replaceAll("\\+", "%20");
        response.setHeader("Content-disposition", "attachment;filename*=utf-8''" + fileName);
        
        // 3. 将前端 JSON 数据转换为实体类并写入 Excel
        List<YourEntity> dataList = convertToEntity(editedData);
        EasyExcel.write(response.getOutputStream(), YourEntity.class)
            .sheet("报表")
            .doWrite(dataList);
    }
}