java-下载excel 数据库数据映射到excel（类似查表展示）

package com.cck.common.Utils;

import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

/**
 * @program: Iplan_NkaRka_server
 * @description: DownExcel
 * @author: LiuZhiFeng
 * @create: 2021-07-30 10:31
 **/
public class RowDataExcelUtil {

    public static void writeRowExcel(List<LinkedHashMap> list,
                                     HttpServletResponse response,
                                     String channelType) throws IOException {

        XSSFWorkbook xssfWorkbook = null;
        xssfWorkbook = new XSSFWorkbook();

        //创建工作表
        XSSFSheet xssfSheet;
        xssfSheet = xssfWorkbook.createSheet();
        //创建行
        XSSFRow xssfRow;
        //创建列，即单元格Cell
        XSSFCell xssfCell;

        xssfRow = xssfSheet.createRow(0);
        Map map = list.get(0);
        Iterator iterator = map.entrySet().iterator();
        int j=0;
        while (iterator.hasNext()) {
            Entry next = (Entry) iterator.next();
            xssfCell  = xssfRow.createCell(j);
            xssfCell.setCellValue(next.getKey().toString());
            j++;
        }
        int k =0;
        for (int i = 0; i < list.size(); i++) {
            Map map1 = list.get(i);
            xssfRow  = xssfSheet.createRow(i + 1);
            for(Object obj:map1.values()){
                System.out.println("value:"+obj);
                xssfCell = xssfRow.createCell(k);
                xssfCell.setCellValue(String.valueOf(obj));
                k++;
            }
            k=0;
        }

        String headStr = "attachment; filename="" +channelType+ "-RowData.xlsx"";
        response.setContentType("APPLICATION/OCTET-STREAM");
        response.setHeader("Content-Disposition", headStr);//
        OutputStream outl = response.getOutputStream();
        //FileOutputStream outl=new FileOutputStream("D://"+fileName);
        //用输出流写到excel
        try {
            xssfWorkbook.write(outl);
            outl.flush();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            outl.close();
        }

    }

}