springboot导出excel表格（easyExcel）

官方文档
https://www.yuque.com/easyexcel/doc/quickstart

1. 导入pom依赖

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>2.1.6</version>
</dependency>

2.实体类

@ExcelProperty是设置excel中的第一行

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Form {
    @ExcelProperty("id")
    private int id;
    @ExcelProperty("老师id")
    private int teacherId;
    @ExcelProperty("课程id")
    private int lessonId;
    @ExcelProperty("学生表现")
    private String studentScore;
    @ExcelProperty("老师表现")
    private String teacherScore;
    @ExcelProperty("建议")
    private String suggestion;
    @ExcelProperty("等级")
    private int rank;

    @ExcelProperty("课程名")
    private String lessonName;
    @ExcelProperty("任课老师名字")
    private String teacherName;

    private String img;

}

3. 为了方便，我就直接写在controller类中了
   肯定有更好的实现方式

 @GetMapping("/print")
 @ResponseBody
    public String simpleWrite(HttpServletResponse response) throws IOException {
    	//文件名
        String name=System.currentTimeMillis()+".xlsx";
        //PATH是存储路径
        String fileName = PATH+name;
		//得到查询结果forms，这不是重点
        List<Form> forms = adminService.selectAll();
        for (Form form : forms) {
            form.setTeacherName(teacherService.selectById(form.getTeacherId()).getName());
            form.setLessonName(lessonService.selectById(form.getLessonId()).getName());
            System.out.println(form);
        }
        //这一步是保存到本地，
        EasyExcel.write(fileName, Form.class).sheet("课程评价").doWrite(forms);

        //从本地下载文件
        download(fileName,response,name);
        return "success";

    }
    //下载excel文件
    public void download(String fileName,HttpServletResponse res,String name) {
        res.setHeader("content-type", "application/octet-stream");
        res.setContentType("application/octet-stream");
        res.setHeader("Content-Disposition", "attachment;filename=" + name);
        byte[] buff = new byte[1024];
        BufferedInputStream bis = null;
        OutputStream os = null;
        try {
            os = res.getOutputStream();
            bis = new BufferedInputStream(new FileInputStream(new File( fileName)));
            int i = bis.read(buff);
            while (i != -1) {
                os.write(buff, 0, buff.length);
                os.flush();
                i = bis.read(buff);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (bis != null) {
                try {
                    bis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        System.out.println("download success");
    }

右下角浏览器就会自动下载了