定义ExcelViewObject

public class ExcelViewObject {
	@ColumnWidth(12)
    @ExcelProperty(value = "首列")
    private String type;
    
    @ColumnWidth(12)
    @ExcelProperty(value = "第二列")
    private String name;
}

插入数据，输出到ByteArrayOutputStream；ByteArrayOutputStream作为常用的字节流，输出后可以作为接口数据来传送；

	ByteArrayOutputStream out = new ByteArrayOutputStream();
	List<ExcelViewObject> data = new ArrayList<>();

将要插入的数据遍历插入，如果不需转换直接addAll();
	for (POObject item : list) {
            ExcelViewObject excelViewObject = new ExcelViewObject();
            BeanUtils.copyProperties(item, excelViewObject);
            data.add(ExcelViewObject);
		}
		
    WriteCellStyle headWriteCellStyle = new WriteCellStyle();
    WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
    contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.RIGHT);
    HorizontalCellStyleStrategy horizontalCellStyleStrategy =
            new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
    EasyExcel.write(out, ExcelViewObject.class)
    		.registerWriteHandler(horizontalCellStyleStrategy).sheet().doWrite(data);