springboot生成excel並保存在服務器指定路徑

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>5.0.0</version>
</dependency>

package com.gllic.workweixin.utils;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;

import javax.servlet.http.HttpServletResponse;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.List;

/**
 * @program: workweixin-mobile-api
 * @ClassName ExcelUtil
 * @description:
 * @author: Marlo
 * @create: 2021-07-29 10:06
 * @Version 1.0
 **/
public class ExcelUtil {
    /**
     * 導出類
     *
     * @param response   響應
     * @param fileName   文件名
     * @param columnList 每列的標題名
     * @param dataList   導出的數據
     */
    public static void uploadExcelAboutUser(HttpServletResponse response, String fileName, List<String> columnList, List<List<String>> dataList) {
        //聲明輸出流
        FileOutputStream output = null;
        //設置響應頭
        //setResponseHeader(response, fileName);
        try {
            //獲取輸出流
            output = new FileOutputStream("C:\\myselefzxq\\image\\testFile.xls");
            //內存中保留1000條數據，以免內存溢出，其余寫入硬盤
            SXSSFWorkbook wb = new SXSSFWorkbook(1000);
            //獲取該工作區的第一個sheet
            Sheet sheet1 = wb.createSheet("sheet1");
            int excelRow = 0;
            //創建標題行
            Row titleRow = sheet1.createRow(excelRow++);
            for (int i = 0; i < columnList.size(); i++) {
                //創建該行下的每一列，並寫入標題數據
                Cell cell = titleRow.createCell(i);
                cell.setCellValue(columnList.get(i));
            }
            //設置內容行
            if (dataList != null && dataList.size() > 0) {
                //序號是從1開始的
                //int count =0;
                //外層for循環創建行
                for (int i = 0; i < dataList.size(); i++) {
                    Row dataRow = sheet1.createRow(excelRow++);
                    //內層for循環創建每行對應的列，並賦值
                    for (int j = 0; j < dataList.get(0).size(); j++) {//由於多了一列序號列所以內層循環從-1開始
                        Cell cell = dataRow.createCell(j);
                        cell.setCellValue(dataList.get(i).get(j));
                            /*if(j==0){//第一列是序號列，不是在數據庫中讀取的數據，因此手動遞增賦值
                                //cell.setCellValue(count++);
                            }else{//其余列是數據列，將數據庫中讀取到的數據依次賦值
                                cell.setCellValue(dataList.get(i).get(j));
                            }*/
                    }
                }
            }/*

            //准備將Excel的輸出流通過response輸出到頁面下載
            //八進制輸出流
            response.setContentType("application/octet-stream");

            //這后面可以設置導出Excel的名稱，此例中名為student.xls
            response.setHeader("Content-disposition", "attachment;filename=employee.xls");

            //刷新緩沖
            response.flushBuffer();*/

            //workbook將Excel保存到指定路徑
            wb.write(output);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 關閉輸出流
                if (output != null) {
                    output.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /*
        設置瀏覽器下載響應頭
     */
    private static void setResponseHeader(HttpServletResponse response, String fileName) {
        try {
            try {
                fileName = new String(fileName.getBytes(), "ISO8859-1");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            response.setContentType("application/octet-stream;charset=UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}


測試用例：

List<String> columnList = new ArrayList<>();
columnList.add("title1");
columnList.add("title2");
columnList.add("title3");
columnList.add("title4");
columnList.add("title5");
//數據
List<List<String>> dataList = new ArrayList<>();
List<String> columnList1 = new ArrayList<>();
columnList1.add("data11");
columnList1.add("data12");
columnList1.add("data13");
columnList1.add("data14");
columnList1.add("data15");
List<String> columnList2 = new ArrayList<>();
columnList2.add("data21");
columnList2.add("data22");
columnList2.add("data23");
columnList2.add("data24");
columnList2.add("data25");
dataList.add(columnList1);
dataList.add(columnList2);
//轉存到excel
//ExcelUtil.uploadExcelAboutUser(response,"測試exportExcel",columnList,dataList);