使用spring MVC框架进行文件上传

使用spring MVC框架进行文件上传，步骤如下：

1：配置web.xml文件。定义DispatcherServlet，DispatcherServlet处理的请求（.htm）也在同一个web.xml文件里使用url-mapping定义映射。

<servlet>
  <servlet-name>upload</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet
  </servlet-class>
  <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
  <servlet-name>upload</servlet-name>
  <url-pattern>*.htm</url-pattern>
</servlet-mapping>
2：定义upload-servlet.xml文件。
<bean id="multipartResolver"
       class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- set the max upload size100MB -->
        <property name="maxUploadSize">
        <value>104857600</value>
    </property>
    <property name="maxInMemorySize">
        <value>4096</value>
    </property>
   </bean>
<bean id="urlMapping"
  class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">       
<property name="mappings">           
  <props>               
  <prop key="/upload.htm">uploadController</prop>           
  </props>       
</property>   
</bean>
     <bean id="uploadController" class="FileUploadController">
      <property name="commandClass"><value>FileUploadBean</value></property>
      <property name="uploadDir"><value>E:/</value></property>
      <property name="formView"><value>fail</value></property>
  <property name="successView"><value>confirmation</value></property>
</bean>  
3：定义控制类，commandClass及方法。控制类中最重要的方法是initBinder()它给spring注册了一个编辑器对
request中的multipart实体进行处理，如果没有这个方法，上传将不能进行。
<--------------------------控制类------------------->
public class FileUploadController extends SimpleFormController {
    private static Log log =
        LogFactory.getLog(FileUploadController.class);
    private String uploadDir;//上传文件路径

    protected ModelAndView onSubmit(HttpServletRequest request,
            HttpServletResponse response, Object cmd, BindException errors)
            throws Exception {

            FileUploadBean bean = (FileUploadBean) cmd;
            byte[] bytes = bean.getFile();
          
            //cast to multipart file so we can get additional information
            MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
            CommonsMultipartFile file = (CommonsMultipartFile) multipartRequest.getFile("file");

            String uploadDir = this.getUploadDir();

            File dirPath = new File(uploadDir);
            if (!dirPath.exists()) {
                dirPath.mkdirs();
            }
            String sep = System.getProperty("file.separator");
            if (log.isDebugEnabled()) {
                log.debug("uploading to: " + uploadDir + sep +
                file.getOriginalFilename());
                }
            File uploadedFile = new File(uploadDir + sep
                    + file.getOriginalFilename());
            FileCopyUtils.copy(bytes, uploadedFile);
            System.out.println("********************************");
            System.out.println(uploadedFile.getAbsolutePath());
            System.out.println(bytes.length);
            System.out.println("********************************");
           
     
        return new ModelAndView(getSuccessView() + ".jsp");
    }

    protected void initBinder(HttpServletRequest request,
            ServletRequestDataBinder binder) throws ServletException {
        binder.registerCustomEditor(byte[].class,
                new ByteArrayMultipartFileEditor());
    }
    public void setUploadDir(String uploadDir){
        this.uploadDir = uploadDir;
    }
    public String getUploadDir(){
        return this.uploadDir;
    }
}
<--------------------------控制类------------------------->
<---------------------定义commandClass-------------------->
public class FileUploadBean {

    private byte[] file;

    public void setFile(byte[] file) {
        this.file = file;
    }

    public byte[] getFile() {
        return file;
    }

}
<---------------------定义commandClass-------------------->
4：定义一个form表单index.jsp
<form method="post" action="upload.htm" enctype="multipart/form-data">
<input type="file" name="file"/>
<input type="submit"/>
5：定义confirmation.jsp及fail.jsp
confirmation.jsp如下：
<%@ page contentType="text/html; charset=GBK" %>
<html>
<head>
<title>
successView
</title>
</head>
<body bgcolor="#ffffff">
<h1>
Upload Successful
</h1>
</body>
</html>

fail.jsp如下：
<html>
<head>
<title>Upload a file please</title>
</head>
<body>
<h1>no file,Please upload a file</h1>
<form method="post" action="uploadfile.htm" enctype="multipart/form-data">
<input type="file" name="file"/>
<input type="submit"/>
</form>
</body>
</html>
6：运行tomcat。
预览 ie里面:http://localhost/springmvc/index.jsp
注：
a：文件目录为tomcat-HOME/webapps/springmvc/
.jsp文件都放在根目录下，.class文件放在/WEB-INF/classes/中

其他文件放在/WEB-INF/里面。
b：如果连上面的你都有疑问，那还是去看看spring的基础知识吧。