EasyExcel新增三列数据

为了新增三列数据，我们需要在ExcelTest类中进行如下操作：
1. 在ExcelWriterSheetBuilder中使用head方法添加表头信息。
2. 在ExcelWriterSheetBuilder中使用registerWriteHandler方法添加需要写入的数据。
3. 在ExcelWriterSheetBuilder中使用registerWriteHandler方法添加需要写入的数据。
4. 在ExcelWriterSheetBuilder中使用registerWriteHandler方法添加需要写入的数据。

下面是示例代码：

public class ExcelTest {
    @Test
    public void test() {
        // 临时文件路径
        String writerFilePath = "D:/temp/device_" + IdUtil.fastUUID() + ".xls";
        try (FileInputStream in = new FileInputStream("D:/temp/template.xls")) {
            // 生成错误信息的文件
            ExcelWriterBuilder writerBuilder = EasyExcel.write(writerFilePath)
                    .withTemplate(in)
                    .excelType(ExcelTypeEnum.XLS)
                    .needHead(true);
            ExcelWriterSheetBuilder writerSheetBuilder = EasyExcel.writerSheet("Sheet1");
            writerSheetBuilder.head(head());
            writerBuilder.registerWriteHandler(new CommentWriteHandler(1, "IMEI已被分配"));
            writerBuilder.registerWriteHandler(new ColumnWidthStyleStrategy());
            writerBuilder.registerWriteHandler(new FillStyleStrategy());
            writerBuilder.registerWriteHandler(new FontStyleStrategy());
            ExcelWriter excelWriter = writerBuilder.build();
            excelWriter.write(new ArrayList<>(), writerSheetBuilder.build());
            excelWriter.finish();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private List<List<String>> head() {
        List<List<String>> head = new ArrayList<>();
        List<String> head0 = new ArrayList<>();
        head0.add("列1");
        List<String> head1 = new ArrayList<>();
        head1.add("列2");
        List<String> head2 = new ArrayList<>();
        head2.add("列3");
        List<String> head3 = new ArrayList<>();
        head3.add("列4");
        head.add(head0);        head.add(head1);
        head.add(head2);
        head.add(head3);
        return head;
    }
}