easyexcel大数据量（百万数据）,写入到excel

Posted 2023-03-03 qq_40711092

代码

    /**
     * easyexcel大数据量（百万数据）,写入到excel
     */
    @Test
    void bigData() throws FileNotFoundException 
        //输出流，确定文件存放位置
        FileOutputStream fileOutputStream = new FileOutputStream("E:\\\\tmp\\\\user.xlsx");
        //所有数据
        ArrayList<User> users = new ArrayList<>();
        for (int i = 0; i < 100 * 30000; i++) 
            User user = new User();
            user.setCjsj(new Date().toString());
            user.setId(i);
            user.setLxfs(i + "");
            user.setYxds("广州");
            user.setTzqy("广东");
            users.add(user);
        
        //将数据切分成多个，放置到不同的sheet
        ArrayList<List<User>> objects = new ArrayList<>();
        int size = 100 * 200;
        int sheetNum = users.size() / size + (users.size() % size > 0 ? 1 : 0);
        for (int i = 0; i < sheetNum; i++) 
            objects.add(users.subList(i * size, (i + 1) * size <= users.size() ? (i + 1) * size : users.size()));
        
        ExcelWriter build = EasyExcel.write(fileOutputStream, User.class)
                .build();
        //将数据写入到excel，循环写入
        for (int i = 0; i < objects.size(); i++) 
            build.write(objects.get(i), EasyExcel.writerSheet("表格" + i).build());
        
        build.finish();