如表示url资源时应该用斜杠 “/”

如表示硬盘路径时用斜杠“\\”

factory.setRepository(new File(this.getServletContext().getRealPath("/temp")));

……

FileItem item;

……

item.delete();

5、 限制文件上传的最大值问题：

调用解析器的：upload.setFileSizeMax(1024*1024);  //上传文件不能超过1M。如果超出大小，需要给用户友好提示：

try{

  ……

}catch (FileUploadBase.FileSizeLimitExceededException e) {

request.setAttribute("message", "上传文件不能超过1M!!");

}

     6、 ProgressListener 显示上传进度问题：

ProgressListener progressListener = new ProgressListener() {

public void update(long pBytesRead, long pContentLength, int pItems) {

System.out.println("到现在为止,  " + pBytesRead + " 字节已上传，总大小为 "  + pContentLength);

}

};

upload.setProgressListener(progressListener);

UploadServlet.java

import java.io.File;
            import java.io.FileOutputStream;
            import java.io.IOException;
            import java.io.InputStream;
            import java.io.PrintWriter;
            import java.util.List;
            import java.util.UUID;

import javax.servlet.ServletException;
            import javax.servlet.http.HttpServlet;
            import javax.servlet.http.HttpServletRequest;
            import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
            import org.apache.commons.fileupload.FileUploadBase.FileSizeLimitExceededException;
            import org.apache.commons.fileupload.FileUploadException;
            import org.apache.commons.fileupload.disk.DiskFileItemFactory;
            import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class UploadServlet2 extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)  throws ServletException, IOException {
                             doPost(request,response);
                     }
                   public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  
                           // request.setCharacterEncoding("UTF-8");

try {
                              // 1、建立工厂对象
                                  DiskFileItemFactory factory = new DiskFileItemFactory();
                              //factory.setRepository(new File("F:\\"));
   
                              // 2、得到上传文件解析器
                                  ServletFileUpload upload = new ServletFileUpload(factory);
                                  upload.setHeaderEncoding("utf-8");//处理上传文件
 
                              // 3、设定上传文件尺寸
                                   upload.setFileSizeMax(1024*1024);
           
                              // 4、进行解析，得到fileItem对象
                                 List<FileItem> list = upload.parseRequest(request);

// 5、对list进行迭代处理
                                 for (FileItem item : list) {
                                     if (item.isFormField()) {// 表单普通输入项

String paramName = item.getFieldName();
                                        //String paramValue = item.getString();

//paramValue = new String(paramValue.getBytes("ISO8859-1"),"UTF-8");
                                         String paramValue=item.getString("utf-8");
                                         System.out.println("普通输入项" + paramName + "==" + paramValue);

} else {// 上传文件处理
                                       //获取上传文件名
                                         String fileName = item.getName();
                                       // 如果文件xxx中有目录，则去掉目录部分只保留文件名
                                         fileName = fileName.substring(fileName.lastIndexOf("\\") + 1);
                                               System.out.println("name =" + fileName);
     
                                       if (!fileName.equals(" ")) {
      
                                               fileName =refactorFileName(fileName) ;
                                               System.out.println("filename = " + fileName);

InputStream in = item.getInputStream();
                                               File file = new File("F:\\" + fileName);
                                               FileOutputStream fos = new FileOutputStream(file);

byte[] buffer = new byte[1024];
                                               int len = 0;
                                        while ((len - in.read(buffer)) > 0) {
                                                    fos.write(buffer, 0, len);
                                         }

fos.flush();
                                        fos.close();
                                        in.close();
                                        item.delete();
  
                                               request.setAttribute("message", "文件上传成功");

}
                                      }
                                   }

}catch(FileSizeLimitExceededException e1){
                                                e1.printStackTrace();
                                    request.setAttribute("message", "上传文件尺寸太大！！！");
                                 }catch (FileUploadException e) {
                                               e.printStackTrace();
                                    request.setAttribute("message", "文件上传失败！！！");
                                 }
                                     request.getRequestDispatcher("/message.jsp").forward(request, response);  
                                 }
 
              public String refactorFileName(String fileName){
                      return UUID.randomUUID().toString() + "_" + fileName;  
              }

}