EasyExcel的讀寫操作

一、寫操作

1.1 實體類

讀操作添加 @ExcelProperty注解，並且value值為excel的錶頭名稱

@Data
public class User {
    
    @ExcelProperty(value = "用戶編號",index = 0)
    private int id;
    @ExcelProperty(value = "用戶名稱",index = 1)
    private String name;

}

1.2 測試寫操作

public class TestWrite {
    
    public static void main(String[] args) {
    
        String fileName = "C:\\data\\hzxy.xlsx";
        EasyExcel.write(fileName,User.class)
                .sheet("寫操作")
                .doWrite(data());
                }
                }

private static List<User> data(){
    
        ArrayList<User> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
    
            User user = new User();
            user.setId(i);
            user.setName("張三"+i);
            list.add(user);
        }
        return list;
    }
    }

二、寫操作(寫操作需要繼承一個監聽器，進行一行一行讀取)

2.1 監聽器

invoke方法會進行excel一行一行讀取，只會從第二行讀取，第一行為錶頭

public class ExcelListener extends AnalysisEventListener<User> {
    

    //一行一行讀取excel的內容，把每行內容封裝
    //第一行不讀，因為第一行為錶頭
    @Override
    public void invoke(User user, AnalysisContext analysisContext) {
    
        System.out.println(user);
    }

    //錶頭是從該方法讀取
    @Override
    public void invokeHead(Map<Integer, CellData> headMap, AnalysisContext context) {
    
        System.out.println("錶頭:"+headMap);
        super.invokeHead(headMap, context);
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
    

    }
}

2.2 測試代碼

public class TestWrite {
    
    public static void main(String[] args) {
    
        String fileName = "C:\\data\\hzxy.xlsx";
//        EasyExcel.write(fileName,User.class)
//                .sheet("寫操作")
//                .doWrite(data());
        EasyExcel.read(fileName,User.class,new ExcelListener())
                .sheet("讀操作")
                .doRead();
    }

三、實現

3.1 導出

public void exportData(HttpServletResponse response) {
    
        try {
    
            //設置下載信息
            response.setContentType("application/vnd.ms-excel");
            response.setCharacterEncoding("utf-8");

            String fileName = URLEncoder.encode("課程分類","UTF-8");
            response.setHeader("Content-disposition","attachment;filename="+fileName+".xlsx");
            //查詢所有課程數據
            List<Subject> subjectList = baseMapper.selectList(null);

            List<SubjectEeVo> subjectEeVos = new ArrayList<>();

            for (Subject subject : subjectList) {
    
                SubjectEeVo subjectEeVo = new SubjectEeVo();
                BeanUtils.copyProperties(subject,subjectEeVo);
                subjectEeVos.add(subjectEeVo);
            }

            EasyExcel.write(response.getOutputStream(), SubjectEeVo.class)
                    .sheet("課程分類")
                    .doWrite(subjectEeVos);
        } catch (Exception e) {
    
            e.printStackTrace();
        }
    }

3.2 導入

 @Override
    public void importData(MultipartFile file) {
    
        try {
    
            EasyExcel.read(file.getInputStream(),SubjectEeVo.class,subjectListener)
                    .sheet()
                    .doRead();
        } catch (IOException e) {
    
           throw  new GgktException(20001,"導入失敗");
        }
    }

@Component
public class SubjectListener extends AnalysisEventListener<SubjectEeVo> {
    

    @Autowired
    private SubjectMapper subjectMapper;

    @Override
    public void invoke(SubjectEeVo subjectEeVo, AnalysisContext analysisContext) {
    
        Subject subject = new Subject();
        BeanUtils.copyProperties(subjectEeVo,subject);
        subjectMapper.insert(subject);
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
    

    }
}