EasyExcel实现文件的上传和下载

忘是亡心i 2023-10-11 15:09 60阅读 0赞

*  实体类

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    @ContentRowHeight(20) //内容的行高
    @HeadRowHeight(30) //表头的行高
    public class Student {
        
    
        @ExcelProperty(value = "ID")
        @ColumnWidth(30)
        private String id;
    
        @ExcelProperty(value = "姓名")
        private String name;
    
        @ExcelProperty(value = "生日")
        private Date birth;
    
        @ExcelProperty(value = "分数")
        private Double score;
    }

*  上传文件读取的时候需要一个监听器类

/**
     * excel文件读取的监听器，如果上传了文件，我们可以将service类中的业务逻辑在这个监听器中写。
     */
    @Component
    public class StudentReadListener extends AnalysisEventListener<Student>{
        
    
        private List<Student> students = new ArrayList<>();
    
        /**
         * 每读取一行的回调
         * @param student
         * @param analysisContext
         */
        @Override
        public void invoke(Student student, AnalysisContext analysisContext) {
        
            System.out.println("Student:" + student);
            students.add(student);
        }
    
        /**
         * 全部读取完的回调
         * @param analysisContext
         */
        @Override
        public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        
            System.out.println("读取数据完成，总共有" + students.size() + "条数据！");
            students = new ArrayList<>();
        }
    }

*  上传和下载的controller

@RestController
    public class DownloadController {
        
    
        @Autowired
        private StudentReadListener studentReadListener;
    
        /**
         * 导出excel文件
         */
        @GetMapping("download")
        public void download(HttpServletResponse response) throws IOException {
        
            response.setContentType("application/octet-stream");
            response.setCharacterEncoding("UTF-8");
            String filename = URLEncoder.encode("学生信息", "UTF-8");
            response.setHeader("Content-Disposition", "attachment; filename="+filename+".xlsx");
            ExcelWriterBuilder write = EasyExcel.write(response.getOutputStream(), Student.class);
            write.sheet().doWrite(getData());
        }
    
        /**
         * 上传文件
         */
        @PostMapping("/upload")
        public void upload(MultipartFile file,HttpServletResponse response) throws IOException {
        
            ExcelReaderBuilder read = EasyExcel.read(file.getInputStream(), Student.class, studentReadListener);
            read.sheet().doRead();
            response.setContentType("text/html; charset=UTF-8");
            response.getWriter().write("<h1>上传成功！<h1>");
        }
    
        public List<Student> getData(){
        
            List<Student> list = new ArrayList<>();
            for (int i = 0;i < 10;i++){
        
                Student student = new Student();
                student.setBirth(new Date());
                student.setId(UUID.randomUUID().toString().replace("-",""));
                student.setName("name" + i);
                student.setScore(Double.parseDouble(String.valueOf(i)));
                list.add(student);
            }
            return list;
        }
    
    }

注意：在上传文件时，要修改表单的enctype属性值