使用ServletFileUpload实现上传

 转载自http://blog.csdn.net/zsw2zkl/article/details/7426007

1.首先我们应该为上传的文件建一个存放的位置，一般位置分为临时和真是文件夹，那我们就需要获取这俩个文件夹的绝对路径，在servlet中我们可以这样做

[java] view plaincopyprint?

1. ServletContext application = this.getServletContext(); 
2. String tempDirectory = application.getRealPath(Constant.TEMP_DIRECTORY) +"/"; 
3. String realDirectory = application.getRealPath(Constant.REAL_DIRECTORY) +"/"; 

ServletContext application = this.getServletContext();String tempDirectory = application.getRealPath(Constant.TEMP_DIRECTORY) + "/";String realDirectory = application.getRealPath(Constant.REAL_DIRECTORY) + "/";

然后建立文件工厂即仓库一个参数表示存放多大后flush，

[java] view plaincopyprint?

1. FileItemFactory factory = new DiskFileItemFactory(Constant.SIZE_THRESHOLD,new File(tempDirectory)); 
2. ServletFileUpload upload = new ServletFileUpload(factory); 

FileItemFactory factory = new DiskFileItemFactory(Constant.SIZE_THRESHOLD,new File(tempDirectory));ServletFileUpload upload = new ServletFileUpload(factory);

2.对上传的文件进行设定

[java] view plaincopyprint?

1. upload.setSizeMax(500*1024*1024);//设置该次上传最大值为500M 

upload.setSizeMax(500*1024*1024);//设置该次上传最大值为500M

3,.解析请求正文，获取上传文件，不抛出异常则写入真是路径

[java] view plaincopyprint?

1. List<FileItem> list = upload.parseRequest(request); 
2.             Iterator<FileItem> iter = list.iterator(); 
3.             while (iter.hasNext()) { 
4.                 FileItem item = iter.next(); 
5.                 //item.isFormField()用来判断当前对象是否是file表单域的数据  如果返回值是true说明不是 就是普通表单域 
6.                 if(item.isFormField()){ 
7.                     System.out.println( "普通表单域" +item.getFieldName()); 
8.                     System.out.println(item.getString("utf-8")); 
9.  
10.                 }else{ 
11.                     //System.out.println("file表单域" + item.getFieldName()); 
12.                     /*
13.                      * 只有file表单域才将该对象中的内容写到真实文件夹中
14.                      */ 
15.                     String lastpath = item.getName();//获取上传文件的名称 
16.                     lastpath = lastpath.substring(lastpath.lastIndexOf(".")); 
17.                     String filename = UUID.randomUUID().toString().replace("-","") + lastpath; 
18.                     item.write(new File(realDirectory+filename)); 

List<FileItem> list = upload.parseRequest(request);Iterator<FileItem> iter = list.iterator();while (iter.hasNext()) {FileItem item = iter.next();//item.isFormField()用来判断当前对象是否是file表单域的数据  如果返回值是true说明不是 就是普通表单域if(item.isFormField()){System.out.println( "普通表单域" +item.getFieldName());System.out.println(item.getString("utf-8"));}else{//System.out.println("file表单域" + item.getFieldName());/* * 只有file表单域才将该对象中的内容写到真实文件夹中  */String lastpath = item.getName();//获取上传文件的名称lastpath = lastpath.substring(lastpath.lastIndexOf("."));String filename = UUID.randomUUID().toString().replace("-", "") + lastpath;item.write(new File(realDirectory+filename));