springmvc文件上传

　　1.spring-serlvet.xml　　

 <!-- 文件上传 -->
     <bean class="org.springframework.web.multipart.commons.CommonsMultipartResolver" id="multipartResolver">
         <!-- 编码方式 -->
        <property name="defaultEncoding" value="utf-8"></property>
        <!-- 文件最大 -->
        <property name="maxUploadSize" value="10485760000"></property> 
        <!-- 缓存-->
        <property name="maxInMemorySize" value="40960"></property>    
     </bean>

注：这里bean的Id一定要写multipartResolver,前面不能加commons。

　　2.Controller（一共有两种方法）

@RequestMapping("/load")
    public String downLoad(
            @RequestParam("wenjian")CommonsMultipartFile multiFile,
            HttpServletRequest request) {
        if (!multiFile.isEmpty()) {
            File test = new File("D://upload");
            if(!test.exists()){
                test.mkdirs();
            }
            try {
                FileOutputStream out = new FileOutputStream("D://upload//"
                        + multiFile.getOriginalFilename());
                InputStream in = multiFile.getInputStream();
                int len;
                byte[] buffer = new byte[1024 * 1024 * 10];
                while ((len = in.read(buffer)) > 0) {
                    out.write(buffer, 0, len);
                    out.flush();
                }
                out.close();
                in.close();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
        return "/success";
    }

    @RequestMapping("load1")
    public String upload(HttpServletRequest request,HttpServletResponse response){
        CommonsMultipartResolver  multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
        
        if (multipartResolver.isMultipart(request)) {
            MultipartHttpServletRequest multipartHttpServletRequest = (MultipartHttpServletRequest) request;
            
            Iterator<String> iter = multipartHttpServletRequest.getFileNames();
                
            while(iter.hasNext()){
                MultipartFile file = multipartHttpServletRequest.getFile(iter.next());
                System.out.println(file.getOriginalFilename()+"*-------------------");
                if(file != null){
                    File test = new File("D://upload");
                    if(!test.exists()){
                        test.mkdirs();
                    }
                    File filePath = new File("D://upload/"+file.getOriginalFilename());
                    try {
                        file.transferTo(filePath);
                    } catch (Exception e) {
                        throw new RuntimeException(e);
                    }
                }
            }
            
        }
        
        return "/success";
    }

　3.jsp

<form name="up" action="<%=request.getContextPath() %>/file/load" method="post"
            enctype="multipart/form-data">
            <input type="file" name="wenjian" />
            <input type="submit" value="上传" />
        </form>

　　　在做springmvc上传时需要两个jar文件

　　　　　　1.com.springsource.org.apache.commons.fileupload-1.2.0.jar 

　　　　　　2.com.springsource.org.apache.commons.io-1.4.0.jar　

　　　这两个jar文件有的时候名字会变commons.fileupload-1.2.0.jar ，commons.io-1.4.0.jar　,其实都一样

如果没有这两个jar包回报错:java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory

如果没有multipart解析器回报这个错：org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.ClassCastException: org.apache.catalina.connector.RequestFacade