SpringMVC上传文件的三种方式

直接上代码吧,大伙一看便知

这时:commonsmultipartresolver 的源码,可以研究一下 http://www.verysource.com/code/2337329_1/commonsmultipartresolver.java.html

前台:

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<form name="serForm" action="/SpringMVC006/fileUpload" method="post"  enctype="multipart/form-data">
<h1>采用流的方式上传文件</h1>
<input type="file" name="file">
<input type="submit" value="upload"/>
</form>

<form name="Form2" action="/SpringMVC006/fileUpload2" method="post"  enctype="multipart/form-data">
<h1>采用multipart提供的file.transfer方法上传文件</h1>
<input type="file" name="file">
<input type="submit" value="upload"/>
</form>

<form name="Form2" action="/SpringMVC006/springUpload" method="post"  enctype="multipart/form-data">
<h1>使用spring mvc提供的类的方法上传文件</h1>
<input type="file" name="file">
<input type="submit" value="upload"/>
</form>
</body>
</html>

配置:

<!-- 多部分文件上传 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
     <property name="maxUploadSize" value="104857600" />
     <property name="maxInMemorySize" value="4096" />
     <property name="defaultEncoding" value="UTF-8"></property>
</bean>

后台:

  • 方式一:

    /*
       * 通过流的方式上传文件
       * @RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象
       */
      @RequestMapping("fileUpload")
      public String  fileUpload(@RequestParam("file") CommonsMultipartFile file) throws IOException {
          //用来检测程序运行时间
          long  startTime=System.currentTimeMillis();
          System.out.println("fileName:"+file.getOriginalFilename());
          try {
              //获取输出流
              OutputStream os=new FileOutputStream("E:/"+new Date().getTime()+file.getOriginalFilename());
              //获取输入流 CommonsMultipartFile 中可以直接得到文件的流
              InputStream is=file.getInputStream();
              int temp;
              //一个一个字节的读取并写入
              while((temp=is.read())!=(-1))
              {
                  os.write(temp);
              }
             os.flush();
             os.close();
             is.close();
          } catch (FileNotFoundException e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }
          long  endTime=System.currentTimeMillis();
          System.out.println("方法一的运行时间:"+String.valueOf(endTime-startTime)+"ms");
          return "/success"; 
      }
    
  • 方式二:

    /*
       * 采用file.Transto 来保存上传的文件
       */
      @RequestMapping("fileUpload2")
      public String  fileUpload2(@RequestParam("file") CommonsMultipartFile file) throws IOException {
           long  startTime=System.currentTimeMillis();
          System.out.println("fileName:"+file.getOriginalFilename());
          String path="E:/"+new Date().getTime()+file.getOriginalFilename();
          File newFile=new File(path);
          //通过CommonsMultipartFile的方法直接写文件(注意这个时候)
          file.transferTo(newFile);
          long  endTime=System.currentTimeMillis();
          System.out.println("方法二的运行时间:"+String.valueOf(endTime-startTime)+"ms");
          return "/success"; 
      }
    
  • 方式三:

    /*
       *采用spring提供的上传文件的方法
       */
      @RequestMapping("springUpload")
      public String  springUpload(HttpServletRequest request) throws IllegalStateException, IOException
      {
           long  startTime=System.currentTimeMillis();
           //将当前上下文初始化给  CommonsMutipartResolver (多部分解析器)
          CommonsMultipartResolver multipartResolver=new CommonsMultipartResolver(
                  request.getSession().getServletContext());
          //检查form中是否有enctype="multipart/form-data"
          if(multipartResolver.isMultipart(request))
          {
              //将request变成多部分request
              MultipartHttpServletRequest multiRequest=(MultipartHttpServletRequest)request;
             //获取multiRequest 中所有的文件名
              Iterator iter=multiRequest.getFileNames();
    
              while(iter.hasNext())
              {
                  //一次遍历所有文件
                  MultipartFile file=multiRequest.getFile(iter.next().toString());
                  if(file!=null)
                  {
                      String path="E:/springUpload"+file.getOriginalFilename();
                      //上传
                      file.transferTo(new File(path));
                  }
              }
          }
          long  endTime=System.currentTimeMillis();
          System.out.println("方法三的运行时间:"+String.valueOf(endTime-startTime)+"ms");
      return "/success"; 
      }
    

我们看看测试上传的时间:

第一次我用一个4M的文件:

fileName:test.rar
方法一的运行时间:14712ms
fileName:test.rar
方法二的运行时间:5ms
方法三的运行时间:4ms

第二次:我用一个50M的文件
方式一进度很慢,估计得要个5分钟

方法二的运行时间:67ms
方法三的运行时间:80ms

从测试结果我们可以看到:用springMVC自带的上传文件的方法要快的多!

对于测试二的结果:可能是方法三得挨个搜索,所以要慢点。不过一般情况下我们是方法三,因为他能提供给我们更多的方法

另外,在方法一和方法二的应用中出现了一些问题:

多个文件上传时有一个文件控件没有选择文件:

[code]11:03:07.147 [http-nio-8080-exec-4] DEBUG o.s.w.s.m.a.AnnotationMethodHandlerExceptionResolver - Resolving exception from handler [com.xFee.serverAdmin.controller.ApkInfoController@25a5db]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
11:03:07.147 [http-nio-8080-exec-4] DEBUG o.s.w.s.m.a.ResponseStatusExceptionResolver - Resolving exception from handler [com.xFee.serverAdmin.controller.ApkInfoController@25a5db]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
11:03:07.147 [http-nio-8080-exec-4] DEBUG o.s.w.s.m.s.DefaultHandlerExceptionResolver - Resolving exception from handler [com.xFee.serverAdmin.controller.ApkInfoController@25a5db]: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile]: no matching editors or conversion strategy found
11:03:07.147 [http-nio-8080-exec-4] DEBUG o.s.web.servlet.DispatcherServlet - Null ModelAndView returned to DispatcherServlet with name 'springServlet': assuming HandlerAdapter completed request handling
11:03:07.147 [http-nio-8080-exec-4] DEBUG o.s.web.servlet.DispatcherServlet - Successfully completed request

看来应该是对null转换的时候出现的问题。

所以最后采用方法三才是比较好的方案。

参考:http://www.lai18.com/content/10034534.html

http://www.cnblogs.com/fjsnail/p/3491033.html

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