在EasyJWeb中使用Java Excel API 处理电子表格

在J2EE应用开发中，由于各种各样的原因，经常会需要处理一些旧的Excel格式电子表格数据，或者是生成电子表格。

处理Excel电子表格的方法比如多，比如可以使用jdbc来像读数据库中的数据一样来读取电子表格的内容。这里演示的是使用开源的电子表格处理工具jxl，即Java Excel API来进行处理。关于jxl及相关使用，可以在网上搜索到很多资料。这里只是简单演示在EasyJWeb中的使用方法，这是前段时间公司一个项目中的应用，需要生成一特定的Excel表格，供客户端下载。

WEB MVC中Action中的代码如下：

public class PersonChangeAction extends BaseCrudAction {

private ExcelReportService excelReportService=ExcelReportService.getInstance();

public Page doDownloadMenu(WebForm form, Module module)throws Exception {  
String town=CommUtil.null2String(form.get("queryTown"));
  String village=CommUtil.null2String(form.get("queryVillage"));
  String team=CommUtil.null2String(form.get("queryTeam"));
  String belongDept="";
  ActiveUser user=(ActiveUser)this.getCurrentUser(form);  
  if(!userService.checkAdmin(user))
  {
    belongDept=user.getDept();
  }
    ActionContext.getContext().getResponse().setContentType("application/x-msdownload");
  String fileName="XXXXX人员名单";
  if(!"".equals(town))fileName+="-"+town;
  if(!"".equals(village))fileName+="-"+village;
  if(!"".equals(team))fileName+="-"+team;
  fileName+=".xls";
  ActionContext.getContext().getResponse().setHeader("Content-Disposition","attachment; filename=/""+new String(fileName.getBytes("gbk"),"iso8859-1")+"/"");
  java.io.OutputStream out=com.easyjf.web.ActionContext.getContext().getResponse().getOutputStream();
  excelReportService.personChangeExcelList(out, belongDept, town, village, team);
  return null;
 }

..

}

Action中的doDownloadMenu对应downloadMenu命令，这段代码注要实现了向客户端返回二进制流文件的功能，注意一些细节。其中流中的内容，即Excel表格的内容，通过ExcelReportService的personChangeExcelList方法来处理，该方法属于业务逻辑层，主要功能是把符合条件的对象，添加到Excel表格中，这个方法内容大致如下：

public synchronized void personChangeExcelList(java.io.OutputStream out,String belongDept,String town,String village,String team)
 { 
  String scope = "1=1"; 
  String scope1="1=1";
  Collection paras = new ArrayList();   
 //省略部分查询代码

if(!"1=1".equals(scope))scope1+=" and personId in (select cid as personId from person where "+scope+") ";
  DbPageList pList = new DbPageList(PersonChange.class, scope1, paras);
  pList.doList(1, 500);
  try{
  jxl.write.WritableWorkbook book=jxl.Workbook.createWorkbook(out);
  jxl.write.WritableSheet sheet=book.createSheet("XXXX人员名单", 0);
  int pages=pList.getPages();
  String[] lables={"姓名","镇(乡、街道)","村(居委)","组","户主","就业方式","就业转移时间","就业转移地点","就业单位","就业工资","就业工种","联系电话"};
  for(int l=0;l
   sheet.addCell(new jxl.write.Label(l,0,lables[l]));
  int row=1;  
  for(int p=1;p<=pages;p++)
  {
   pList = new DbPageList(PersonChange.class, scope1, paras);
   pList.doList(p, 500);
   List list=pList.getResult();   
   for(int i=0;i
   {
   PersonChange change=(PersonChange)list.get(i);  
   Person person=(Person)this.dao.get(Person.class,change.getPersonId()); 
   sheet.addCell(new jxl.write.Label(0,row,person.getTrueName()));
   sheet.addCell(new jxl.write.Label(1,row,person.getTown()));
   sheet.addCell(new jxl.write.Label(2,row,person.getVillage()));
   sheet.addCell(new jxl.write.Label(3,row,person.getTeam()));
   sheet.addCell(new jxl.write.Label(4,row,person.getHouseholderName()));
   sheet.addCell(new jxl.write.Label(5,row,logic.showTitle("getWorkType", change.getWorkType())));
   sheet.addCell(new jxl.write.Label(6,row,CommUtil.format(change.getTransferTime())));
   String workPlace=logic.showTitle("workplace", change.getWorkPlace());
   if("".equals(workPlace))workPlace= change.getWorkPlace();
   sheet.addCell(new jxl.write.Label(7,row,workPlace));
   sheet.addCell(new jxl.write.Label(8,row,change.getWorkDept()));
   sheet.addCell(new jxl.write.Label(9,row,logic.showTitle("workSalary", change.getWorkSalary())));
   sheet.addCell(new jxl.write.Label(10,row,logic.showTitle("skills", change.getWorkSubject())));
   sheet.addCell(new jxl.write.Label(11,row,change.getTel()));   
   row++;
   }   
  }  
  book.write();
  book.close();
  }
  catch(Exception e)
  {
   e.printStackTrace();
  }
 }