1、效果如图

2、Controller

@GetMapping("/exportExcel")
    public void exportExcel(@RequestParam(value = "menu") String menu,
                            @RequestParam(value = "dwflglId") int dwflglId,
                            @RequestParam(value = "qjCode") String qjCode,
                            HttpServletResponse response) throws IOException {
      //内容集合
        List<ZjlrysIndexView> jthz = getJthz(dwflglId, qjCode);
        //表头集合
        List<ZjlrysTableHead> header = getHeaderOfHz(dwflglId, qjCode);
        response.setHeader("Content-Disposition", "attachment; filename=Zjlryshz.xlsx");
        // 响应类型,编码
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        String bigTitle = "资金流入预算表";
        EasyExcel.write(response.getOutputStream()).head(getExcelHeader(header, bigTitle)).registerWriteHandler(new Custemhandler()).sheet("资金流入预算导出模板").doWrite(getExportData(jthz));
    }

通过getExcelHeader(header, bigTitle)得到表头集合

private List<List<String>> getExcelHeader(List<ZjlrysTableHead> header, String bigTitle) {
        List<List<String>> head = new ArrayList<>();
        List<String> head0 = new ArrayList<>();
        head0.add(bigTitle);
        head0.add("资金项目");
        head.add(head0);
        head0 = new ArrayList<>();
        head0.add(bigTitle);
        head0.add("行次");
        head.add(head0);
        for (var h : header) {
            head0 = new ArrayList<>();
            head0.add(bigTitle);
            head0.add(h.getName());
            head.add(head0);
        }
        return head;
    }

多级表头

 

private List<List<String>> getExcelHeader(String bigTitle, String nsrsbh, String ssyf) {
        List<List<String>> head = new ArrayList<>();
        head.add(Arrays.asList(bigTitle, "纳税人识别号:", "序号"));
        head.add(Arrays.asList(bigTitle, nsrsbh, "发票代码"));
        head.add(Arrays.asList(bigTitle, "", "发票号码"));
        head.add(Arrays.asList(bigTitle, "", "开票日期"));
        head.add(Arrays.asList(bigTitle, "", "销方税号"));
        head.add(Arrays.asList(bigTitle, "", "销方名称"));
        head.add(Arrays.asList(bigTitle, "所属月份:", "金额"));
        head.add(Arrays.asList(bigTitle, ssyf, "税额"));
        head.add(Arrays.asList(bigTitle, "", "有效税额"));
        head.add(Arrays.asList(bigTitle, "", "勾选日期"));
        head.add(Arrays.asList(bigTitle, "", "发票类型"));
        head.add(Arrays.asList(bigTitle, "", "用途"));
        head.add(Arrays.asList(bigTitle, "", "发票状态"));
        head.add(Arrays.asList(bigTitle, "", "管理状态"));
        head.add(Arrays.asList(bigTitle, "单位：元", "信息来源"));
        return head;
    }

 效果

上图的表头阔度不是下面的的自适应代码。

参考连接：https://blog.csdn.net/jie873440996/article/details/106399471?utm_medium=distribute.pc_relevant_download.none-task-blog-BlogCommendFromBaidu-9.nonecase&depth_1-utm_source=distribute.pc_relevant_download.none-task-blog-BlogCommendFromBaidu-9.nonecas

 

如果想通过实体类来设置二级表头，可以通过@ExcelProperty(value={"一级表头","二级表头"})，多级表头以此类推

EasyExcel.write(response.getOutputStream(), Download.class).sheet("导出模板").doWrite(data(byZtId));

 

通过调用registerWriteHandler来设置表格样式，我这里设置只是设置表头的自适应宽度，创建一个类来继承AbstractColumnWidthStyleStrategy抽象类

package cn.xxxx.xxxx.xxx.utils;

import com.alibaba.excel.metadata.CellData;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

public class Custemhandler extends AbstractColumnWidthStyleStrategy {
    private static final int MAX_COLUMN_WIDTH = 255;
    //the maximum column width in Excel is 255 characters

    public Custemhandler() {
    }

    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<CellData> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
        if (isHead && cell.getRowIndex() != 0) {
            int columnWidth = cell.getStringCellValue().getBytes().length;
            if (columnWidth > MAX_COLUMN_WIDTH) {
                columnWidth = MAX_COLUMN_WIDTH;
            } else {
                columnWidth = columnWidth + 3;
            }
            writeSheetHolder.getSheet().setColumnWidth(cell.getColumnIndex(), columnWidth * 256);

        }
    }


    private final static Logger logger = LoggerFactory.getLogger(Custemhandler.class);
}

最后在doWrite()里面放要导出的数据即可

 private List<List<String>> getExportData(List<ZjlrysIndexView> jthz) {
        List<List<String>> sumList = new ArrayList<>();
        for (var row : jthz) {
            List<String> list = new ArrayList<>();
            list.add(row.getZjxm());
            list.add(String.valueOf(row.getZbY()));
            for (var xm : row.getZjlrysXms()) {
                if (xm.getId() == null) {
                    list.add("");
                } else {
                    if (xm.getZjlrysb().getXsValue() == null || xm.getZjlrysb().getXsValue().compareTo(new BigDecimal("0")) == 0) {
                        list.add("");
                    } else {
                        list.add(xm.getZjlrysb().getXsValue().toString());
                    }
                }
            }
            sumList.add(list);
        }
        return sumList;
    }

总结

（1）表头的List<List<String>>,最外面的List是一列单元格的表头，里面的List的每一个元素代表这一列的每一行表头

(2)数据的List<List<String>>，最外面的List是每一行的数据，里面的List放一行每一列的数据。

 参考链接：

 链接1

 链接2

 链接3