如何在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<lables.length;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<list.size();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();
}
}