在SpringBoot: SpringBoot里面创建导出Excel的接口教程

<dependency>
 <groupId>org.apache.poi</groupId>
 <artifactId>poi</artifactId>
 <version>3.17</version>
</dependency>

import org.apache.poi.hssf.usermodel.*;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Controller
public class ExcelController {

 /**
 * Excel表格导出接口
 * http://localhost:8080/ExcelDownload
 * @param response response对象
 * @throws IOException 抛IO异常
 */
 @RequestMapping("/ExcelDownload")
 public void excelDownload(HttpServletResponse response) throws IOException {
 //表头数据
 String[] header = {"ID", "姓名", "性别", "年龄", "地址", "分数"};

 //数据内容
 String[] student1 = {"1", "小红", "女", "23", "成都青羊区", "96"};
 String[] student2 = {"2", "小强", "男", "26", "成都金牛区", "91"};
 String[] student3 = {"3", "小明", "男", "28", "成都武侯区", "90"};

 //声明一个工作簿
 HSSFWorkbook workbook = new HSSFWorkbook();

 //生成一个表格，设置表格名称为"学生表"
 HSSFSheet sheet = workbook.createSheet("学生表");

 //设置表格列宽度为10个字节
 sheet.setDefaultColumnWidth(10);

 //创建第一行表头
 HSSFRow headrow = sheet.createRow(0);

 //遍历添加表头(下面模拟遍历学生，也是同样的操作过程)
 for (int i = 0; i < header.length; i++) {
  //创建一个单元格
  HSSFCell cell = headrow.createCell(i);

  //创建一个内容对象
  HSSFRichTextString text = new HSSFRichTextString(header[i]);

  //将内容对象的文字内容写入到单元格中
  cell.setCellValue(text);
 }

 //模拟遍历结果集，把内容加入表格
 //模拟遍历第一个学生
 HSSFRow row1 = sheet.createRow(1);
 for (int i = 0; i < student1.length; i++) {
  HSSFCell cell = row1.createCell(i);
  HSSFRichTextString text = new HSSFRichTextString(student1[i]);
  cell.setCellValue(text);
 }

 //模拟遍历第二个学生
 HSSFRow row2 = sheet.createRow(2);
 for (int i = 0; i < student2.length; i++) {
  HSSFCell cell = row2.createCell(i);
  HSSFRichTextString text = new HSSFRichTextString(student2[i]);
  cell.setCellValue(text);
 }

 //模拟遍历第三个学生
 HSSFRow row3 = sheet.createRow(3);
 for (int i = 0; i < student3.length; i++) {
  HSSFCell cell = row3.createCell(i);
  HSSFRichTextString text = new HSSFRichTextString(student3[i]);
  cell.setCellValue(text);
 }

 //准备将Excel的输出流通过response输出到页面下载
 //八进制输出流
 response.setContentType("application/octet-stream");

 //这后面可以设置导出Excel的名称，此例中名为student.xls
 response.setHeader("Content-disposition", "attachment;filename=student.xls");

 //刷新缓冲
 response.flushBuffer();

 //workbook将Excel写入到response的输出流中，供页面下载
 workbook.write(response.getOutputStream());
 }
}

import org.apache.poi.hssf.usermodel.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

/**
 * Excel工具类
 */
public class ExcelUtil {

 /**
 * Excel表格导出
 * @param response HttpServletResponse对象
 * @param excelData Excel表格的数据，封装为List<List<String>>
 * @param sheetName sheet的名字
 * @param fileName 导出Excel的文件名
 * @param columnWidth Excel表格的宽度，建议为15
 * @throws IOException 抛IO异常
 */
 public static void exportExcel(HttpServletResponse response,
     List<List<String>> excelData, 
     String sheetName, 
     String fileName, 
     int columnWidth) throws IOException {

 //声明一个工作簿
 HSSFWorkbook workbook = new HSSFWorkbook();

 //生成一个表格，设置表格名称
 HSSFSheet sheet = workbook.createSheet(sheetName);

 //设置表格列宽度
 sheet.setDefaultColumnWidth(columnWidth);

 //写入List<List<String>>中的数据
 int rowIndex = 0;
 for(List<String> data : excelData){
  //创建一个row行，然后自增1
  HSSFRow row = sheet.createRow(rowIndex++);

  //遍历添加本行数据
  for (int i = 0; i < data.size(); i++) {
  //创建一个单元格
  HSSFCell cell = row.createCell(i);

  //创建一个内容对象
  HSSFRichTextString text = new HSSFRichTextString(data.get(i));

  //将内容对象的文字内容写入到单元格中
  cell.setCellValue(text);
  }
 }

 //准备将Excel的输出流通过response输出到页面下载
 //八进制输出流
 response.setContentType("application/octet-stream");

 //设置导出Excel的名称
 response.setHeader("Content-disposition", "attachment;filename=" + fileName);

 //刷新缓冲
 response.flushBuffer();

 //workbook将Excel写入到response的输出流中，供页面下载该Excel文件
 workbook.write(response.getOutputStream());

 //关闭workbook
 workbook.close();
 }
}

/**
 * Excel表格导出接口
 * http://localhost:8080/ExcelDownload
 * @param response response对象
 * @throws IOException 抛IO异常
 */
@RequestMapping("/ExcelDownload")
public void excelDownload(HttpServletResponse response) throws IOException {

 List<List<String>> excelData = new ArrayList<>();

 List<String> head = new ArrayList<>();
 head.add("第一列");
 head.add("第二列");
 head.add("第三列");

 List<String> data1 = new ArrayList<>();
 data1.add("123");
 data1.add("234");
 data1.add("345");

 List<String> data2 = new ArrayList<>();
 data2.add("abc");
 data2.add("bcd");
 data2.add("cde");

 excelData.add(head);
 excelData.add(data1);
 excelData.add(data2);

 String sheetName = "测试";
 String fileName = "ExcelTest.xls";

 ExcelUtil.exportExcel(response, excelData, sheetName, fileName, 15);
}