Servlet使用Apache fileupload和io包处理文件上传

需要去apache官网下载commons-fileupload和commons-io两个组件，导入项目中。上传的表单就不贴了，各种语言都一样，下面是处理上传的Servlet:

package com.servlet;

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

public class UploadServlet extends HttpServlet {

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    // TODO Auto-generated method stub
    DiskFileItemFactory factory=new DiskFileItemFactory();
    String path=req.getRealPath("/upload/");
    String tempDir=req.getRealPath("/temp/");
    
    //文件临时目录，默认为System.getProperty("java.io.tmpdir")
    factory.setRepository(new File(tempDir));
    //设置文件大小上限，当文件大于此值时，先存储到临时目录，否则存在内存中
    factory.setSizeThreshold(1024*100);
    ServletFileUpload sfu=new ServletFileUpload(factory);
    try {
        List list=sfu.parseRequest(req);
        PrintWriter out=resp.getWriter();
        resp.setContentType("text/html; charset=utf-8");   
         resp.setCharacterEncoding("utf-8");   
        for(FileItem item:list)
        {
            if(item.isFormField())
            {
                out.println(item.getFieldName()+"="+item.getString()+"  ");
            }else{
                try {
                    String value=item.getName();
                    int start=value.lastIndexOf("//");
                    String filename=value.substring(start+1);
                    //使用write方法写入文件,自动处理临时文件
                    item.write(new File(path,filename));
                    
                    //使用文件流写入文件，需要手工删除临时文件，
                    FileOutputStream fos=new FileOutputStream(new File(path,"bb.jpg"));
                    InputStream is=item.getInputStream();
                    byte\[\] bs=new byte\[1024\];
                    int len=0;
                    while((len=is.read(bs, 0, 1024))>-1)
                    {
                        fos.write(bs,0,len);
                    }
                    fos.close();
                    is.close();
                    
                    
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    } catch (FileUploadException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    
}
    

}