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