java commons-fileupload 文件上传

转：http://www.cnblogs.com/popping57/p/3258956.html

使用servlet来实现

1. 配置pom.xml

         <dependency>
   	<groupId>commons-fileupload</groupId>
   	<artifactId>commons-fileupload</artifactId>
   	<version>1.3</version>
         </dependency>
       

2. servlet

       protected void doPost(HttpServletRequest req, HttpServletResponse resp)
   			throws ServletException, IOException {
   	//创建一个文件处理工厂
   	FileItemFactory factory= new DiskFileItemFactory();
   
   	//创建一个存放临时中转的仓库
   	ServletContext servletContext = this.getServletConfig().getServletContext();
   	File repository = (File) servletContext.getAttribute("javax.servlet.context.temdir");
   	((DiskFileItemFactory) factory).setRepository(repository);
   		
   	//创建一个处理上传的处理器
   	ServletFileUpload upload = new ServletFileUpload(factory);
   	try {
   		//获取从表单提交上来的数据，从表单上传的数据会自动被分割，比如一个input:text,input:file，就会被分成两个item
   		List items = upload.parseRequest(req);
   		Iterator iter = items.iterator();
   		while (iter.hasNext()) {
   			FileItem item = iter.next();
   				
   			//检查是否是文件
   			if(item.isFormField()) {
   				//如果不是文件d
   				String name = item.getFieldName();
   				String value =item.getString();
   				System.out.println(name+":"+value);
   			}else {
   			    //如果是文件
   			    String fieldName = item.getFieldName();
   			    //这个fileName是上传文件名
   			    String fileName = item.getName();
   			    System.out.println(fieldName+":"+fileName);
   			    //新建一个文件，用于存储上传的文件
   			    File uploadFile = new File("D:\\",fileName);
   			    item.write(uploadFile);
   			}
   		}
   	} catch (FileUploadException e) {
   		e.printStackTrace();
   	} catch (Exception e) {
   		e.printStackTrace();
   	}
      }
   

3. 在web.xml中配置好servlet
4. 前端页面

   <form action="/swfupload/fupload" enctype="multipart/form-data" method="post"></form>

    在这里，enctype的类型一定要是multipart/form-data,method要是post

使用spring mvc controller来实现

1. 大部分都是和上面的一样，而配置spring mvc可以在前面的博客找到
2. 配置controller

   	@RequestMapping(value="/upload.do",method=RequestMethod.POST)
   	public void upload(HttpServletRequest request, HttpServletResponse response) {
   		//定义一个文件上传工厂,配置一些上传限制
   		DiskFileItemFactory factory = new DiskFileItemFactory();
   		factory.setRepository(new File("D:\\"));
   		
   		//上传实现方法
   		ServletFileUpload upload = new ServletFileUpload(factory);
   		try {
   			//获取表彰提交
   			List items = upload.parseRequest(request);
   			Iterator iter = items.iterator();
   			while (iter.hasNext()) {
   				FileItem item = iter.next();
   				
   				if (item.isFormField()) {
   					//当不是文件的时候
   					String filedName = item.getFieldName();
   					String value = item.getString();
   					System.out.println(filedName + ":" + value);
   				} else {
   					//是文件的时候
   					String fileName = item.getName();
   					String path = ContextLoader.getCurrentWebApplicationContext().getServletContext().getRealPath("/");
   					System.out.println(path);
   					//新建一个文件，并以上传文件名为文件名
   					File uploadFile = new File(path,fileName);
   					//保存上传文件
   					item.write(uploadFile);
   				}
   			}
   		} catch (FileUploadException e) {
   			e.printStackTrace();
   		} catch (Exception e) {
   			e.printStackTrace();
   		}
   	}
   

   @RequestMapping指定了访问的路径和访问的类型
3. 前台页面

   <form action="/swfupload/upload.do" enctype="multipart/form-data" method="post">

   其实swfupload是项目名