用FileUpload实现文件上传

import java.io.File;
import java.util.Iterator;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.MappingDispatchAction;
import org.apache.commons.fileupload. * ;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class UploadFile extends MappingDispatchAction... ... {
private static final int FILE_SIZE = 4194304 ;
public ActionForwardupload(ActionMappingmapping,ActionFormform,
HttpServletRequestrequest,HttpServletResponseresponse)... ... {

try ... ... {

DiskFileItemFactoryfc = new DiskFileItemFactory();
// 设置文件的最大限度，如果超出这个限度，则将文件写入磁盘
fc.setSizeThreshold( 4000 );
// 文件超过最大限度时，写入磁盘的临时路径
fc.setRepository( new File( " E: mp " ));

ServletFileUploadfu = new ServletFileUpload(fc);
// 设置最大文件尺寸，单位为字节，这里是4MB
fu.setSizeMax(FILE_SIZE);

// 得到所有的文件：
ListfileItems = fu.parseRequest(request);
Iteratori = fileItems.iterator();
// 依次处理每一个文件：
while (i.hasNext())... ... {
FileItemfi = (FileItem)i.next();
// 获得文件名，这个文件名包括路径：
StringfileName = fi.getName();
if (fi.getSize() > FILE_SIZE)
throw new Exception( " Fileistoolarge! " );
fileName = fileName.substring(fileName.lastIndexOf( " ")+1,fileName.length());

// 写入文件
fi.write( new File( " e: mps"+fileName));

}


} catch (Exceptione)... ... {
// TODOAuto-generatedcatchblock
e.printStackTrace();
return mapping.findForward( " uploadFail " );
}

return mapping.findForward( " success " );
}
}
页面代码：
<% ...@pagepageEncoding = " utf-8 " %>

< html >
< body >
< formaction = " upload.do " method = " post " enctype = " multipart/form-data " >
< center >
选择文件路径：
< inputtype = filename = " filename " />< br >
< inputtype = submitvalue = " 上传 " />
</ center >

</ form >
</ body >
</ html >