excel导入导出工具

export excel: 1-step:use @ExcelField(lableName="sex") on POJO's field 2-setp: use ExcelUtil's static method export(Class> clazz,List> list,OutputStream os). if need convert the POJO field's value,you make create class implement ExcelConvert. and @ExcelField(lableName="sex",covertClass=SexConv