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一、导入相关jar包，pom依赖如下：
<dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>RELEASE</version> </dependency></div>
二、开始撸代码
1.如果导出功能使用的比较多，可以将其做成一个工具类，对我下面贴出的代码进行改造
//结果返回的是写入的记录数（以下用的是自己业务场景数据）
public int downLoadToExcel(OutputStream outputStream,List<PaimaiMoneyVO> paimaiMoneyVOList) {
//文档对象
HSSFWorkbook wb = new HSSFWorkbook();
int rowNum = 0;
Sheet sheet = wb.createSheet("excel的标题");
Row row0 = sheet.createRow(rowNum++);
//因为场景不同，titil不同，可以在外面写成数组当参数传进来
row0.createCell(0).setCellValue("第一列属性名");
row0.createCell(1).setCellValue("第二列属性名");
row0.createCell(2).setCellValue("第三列属性名");
row0.createCell(3).setCellValue("第四列属性名");
row0.createCell(4).setCellValue("第五列属性名");
row0.createCell(5).setCellValue("第六列属性名");
if (paimaiMoneyVOList != null && paimaiMoneyVOList.size() > 0) {
for (PaimaiMoneyVO paimaiMoneyVO : paimaiMoneyVOList) {
Row row = sheet.createRow(rowNum++);
row.createCell(0).setCellValue(paimaiMoneyVO.getPaimaiId());
row.createCell(1).setCellValue(paimaiMoneyVO.getTitle());
row.createCell(2).setCellValue(paimaiMoneyVO.getUsername());
row.createCell(3).setCellValue(paimaiMoneyVO.getMoney()+"元");
row.createCell(4).setCellValue("升价拍");
row.createCell(5).setCellValue(bidder);
}
}
try {
wb.write(outputStream);
LogEnum.LAW_WARE.info("表数据写入到excel表成功,一共写入了"+(rowNum - 1)+"条数据");
outputStream.close();
} catch (IOException e) {
LogEnum.LAW_WARE.error("流关闭异常！", e);
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
LogEnum.LAW_WARE.error("流关闭异常！", e);
}
}
}
return rowNum - 1;
}
</div>
2.“工具类”写好后，下面就开始使用它了，从上面的函数参数可以看到，我们需要传过去两个对象，一个是输出流OutPutStream，通过流的方式把excel想要到浏览器，
另外一个就是我们需要导出的对象数组，好了，不解释太多，看代码。（下面的方法写在action层，通过struts.xml配置访问即可实现下载）
public void exportBail(){
this.fileName = "excel文件名";
try {
List<PaimaiMoneyVO> paimaiMoneyVOList = new ArrayList<>();
//下面是我的业务场景获取对象数组
if(paimaiMoneySearchParam!=null){
paimaiMoneySearchParam.setVendorId(WebHelper.getVenderId());
paimaiMoneySearchParam.setPageSize(Constants.AUCTION_WARE_PAGE_SIZE);
paimaiMoneySearchParam.setPage(page);
PaimaiMoneyDto paimaiMoneyDto = auctionWareService1.searchPopPaimaiMoneyList(paimaiMoneySearchParam);
if(paimaiMoneyDto!=null){
int count = paimaiMoneyDto.getCount();
int totalPage = count/ Constants.AUCTION_WARE_PAGE_SIZE + (count% Constants.AUCTION_WARE_PAGE_SIZE > 0?1:0);
for(int i=1;i<=totalPage;i++){
paimaiMoneySearchParam.setPage(i);
PaimaiMoneyDto paimaiMoneyResultResult = auctionWareService1.searchPopPaimaiMoneyList(paimaiMoneySearchParam);
if(paimaiMoneyResultResult!=null){
paimaiMoneyVOList.addAll(paimaiMoneyResultResult.getList());
}
}
}
}
OutputStream outputStream = response.getOutputStream();
response.reset();//清空输出流
//下面是对中文文件名的处理
response.setCharacterEncoding("UTF-8");//设置相应内容的编码格式
//解析浏览器
final String userAgent = request.getHeader("USER-AGENT").toLowerCase();
if(userAgent.contains("firefox")){ //火狐浏览器
fileName = new String(fileName.getBytes(), "ISO8859-1");
}else{
fileName = URLEncoder.encode(fileName, "UTF-8"); //其他浏览器
fileName = fileName.Replace("+", "%20"); //encode后替换，解决空格问题（其中%20是空格在UTF-8下的编码 ，如果不这么写，浏览器会用+代替空格）
}
response.setHeader("Content-Disposition", "attachment;filename=" +fileName + ".xls");//指定输出文件名
response.setContentType("application/msexcel");//定义输出类型
int rouNum = ensurePriceListToExcel(outputStream,paimaiMoneyVOList);
LogEnum.LAW_WARE.info("【RiseAuctionAction.downLoadEnsurePriceExcel】导出成功,一共更新了{"+rouNum+"}条记录");
} catch (Exception e) {
LogEnum.LAW_WARE.error("【RiseAuctionAction.downLoadEnsurePriceExcel】导出失败,error is {}", e);
}
}
</div>
三、拓展（详细的工具类开发）
如果你觉得上面写的太简单了，可以继续往下看，我把它整理出了“万能”的工具类，供大家参考。
package com.jd.pop.auction.util.excel;
import com.jd.common.web.result.Result;
import com.jd.pop.auction.util.excel.annotations.ExcelColumn;
import com.jd.pop.auction.util.excel.annotations.ExcelMapping;
import com.jd.pop.auction.util.excel.annotations.apt.ExcelColumnAPT;
import com.jd.pop.auction.util.excel.annotations.apt.ExcelMappingAPT;
import org.apache.log4j.Logger;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.util.CellRangeAddress;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
public class GenerateExcel {
private final static Logger LOG = Logger.getLogger(GenerateExcel.class);
private HSSFWorkbook workbook;
private HSSFCellStyle headStyle;
private HSSFFont headCellFont;
private HSSFCellStyle theadStyle;
private HSSFFont theadCellFont;
private HSSFCellStyle tbodyStyle;
private HSSFFont tbodyCellFont;
private HSSFFont stringFont;
private static final short COLUMN_WIDTH = 15;
private static final short ROW_HEIGHT = 400;
public GenerateExcel() {
this.workbook = new HSSFWorkbook();
//标题
this.headStyle = workbook.createCellStyle();
headStyle.setFillForegroundColor(HSSFColor.GREY_50_PERCENT.index);
headStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
// headStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
headStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
// headStyle.setWrapText(true);
this.headCellFont = workbook.createFont();
headCellFont.setFontHeightInPoints((short)13);
headCellFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
headStyle.setFont(headCellFont);
this.theadStyle = workbook.createCellStyle();
theadStyle.setFillForegroundColor(HSSFColor.WHITE.index);
theadStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
theadStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
theadStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
theadCellFont = workbook.createFont();
theadCellFont.setColor(HSSFColor.BLACK.index);
theadCellFont.setFontHeightInPoints((short) 12);
theadCellFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
theadStyle.setFont(theadCellFont);
tbodyStyle = workbook.createCellStyle();
tbodyStyle.setFillForegroundColor(HSSFColor.WHITE.index);
tbodyStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
tbodyStyle.setBorderBottom(HSSFCellStyl