大多数业务项目中必然会遇到的一个需求，导出数据文件---Excel。
这里简单贴一下自己开发使用的方式方法，抛砖引玉。
也可小白直接大胆食用。
功能Maven依赖：
<dependency><groupId>cn.afterturn</groupId><artifactId>easypoi-base</artifactId><version>4.5.0</version>
</dependency>
<dependency><groupId>cn.afterturn</groupId><artifactId>easypoi-web</artifactId><version>4.5.0</version>
</dependency>
<dependency><groupId>cn.afterturn</groupId><artifactId>easypoi-annotation</artifactId><version>4.5.0</version>
</dependency>业务入口controller，这里很简单
@GetMapping("/exportApply")public void exportApply(BusBasicFlowQuery query, HttpServletResponse response,@RequestHeader(required = false) String lang) throws IOException {query.setSize(20000);// query:这里就是个查询条件，根据个人业务实操就行// 这里就是根据业务需求查询出想要导出的数据集合信息// 重点说明一下：Bd3OrderExcel里面包好你要导出的表格列说明List<Bd3OrderExcel> bd3OrderExcelList = busBasicFlowService.exportApply(query, lang);ExportParams exportParams = new ExportParams();ExcelUtils.exportExcel(response, "北三卡申请", bd3OrderExcelList, Bd3OrderExcel.class, exportParams);}重点说明一下Bd3OrderExcel，这个类注明的导出表格字段名称、顺序，宽度等。
package com.rdss.bus.model.excel;import cn.afterturn.easypoi.excel.annotation.Excel;
import lombok.Data;import java.time.LocalDateTime;@Data
public class Bd3OrderExcel {private Integer id;/*** 申请人身份证号*/@Excel(name = "申请人姓名",width = 30.0)private String operatorName;/*** 申请时间*/@Excel(name = "申请时间",format = "yyyy-MM-dd HH:mm:ss", databaseFormat="yyyy-MM-dd HH:mm:ss" ,width = 30.0)private LocalDateTime applyTime;/*** 申请原因*/@Excel(name = "申请原因",width = 20.0)private String remark;/*** 申请人手机号*/@Excel(name = "申请人手机号",width = 20.0)private String operatorMobile;/*** 申请人身份证号*/@Excel(name = "申请人身份证号",width = 30.0)private String operatorIdcardNum;/*** 申请人邮箱*/@Excel(name = "申请人邮箱",width = 30.0)private String operatorEmail;/*** 申请人机构*/@Excel(name = "申请人机构",width = 30.0)private String operatorOrgName;/*** 审批结果（0-审核中，1-通过，2-不通过*/@Excel(name = "一级审批状态",dict = "approval_result",width = 15.0)private String approveResult_first;/*** 审批人姓名*/@Excel(name = "一级审批人姓名",width = 30.0)private String approveUserName_first;
}导出封装工具类：
import cn.afterturn.easypoi.excel.ExcelExportUtil;
import cn.afterturn.easypoi.excel.entity.ExportParams;
import com.rdss.bus.service.handler.DictHandler;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;/*** excel工具类*/
@Slf4j
public class ExcelUtils {private ExcelUtils(){}@Autowiredprivate static DictHandler dictHandler;/*** Excel导出** @param response response* @param fileName 文件名* @param list 数据List* @param pojoClass 对象Class*/public static void exportExcel(HttpServletResponse response, String fileName, Collection<?> list, Class<?> pojoClass, ExportParams exportParams ) throws IOException {exportParams.setStyle(ExcelStyleUtil.class);Workbook workbook = ExcelExportUtil.exportExcel(exportParams, pojoClass, list);response.setCharacterEncoding("UTF-8");response.setHeader("content-Type", "application/vnd.ms-excel");response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls");ServletOutputStream out = response.getOutputStream();workbook.write(out);out.flush();}/*** Excel导出，先sourceList转换成List<targetClass>，再导出** @param response response* @param fileName 文件名* @param sourceList 原数据List* @param targetClass 目标对象Class*/public static void exportExcelToTarget(HttpServletResponse response, String fileName, Collection<?> sourceList,Class<?> targetClass) throws IllegalAccessException, InstantiationException, IOException {List<Object> targetList = new ArrayList<>(sourceList.size());for(Object source : sourceList){Object target = targetClass.newInstance();BeanUtils.copyProperties(source, target);targetList.add(target);}exportExcel(response, fileName, targetList, targetClass, new ExportParams());}
}
)
