文件上传

1.导入两个jar包

FileUpload下载地址：

　　http://commons.apache.org/fileupload/

　　下载：commons-fileupload-1.2.2-bin.zip    得到：commons-fileupload-1.2.2.jar

　　http://commons.apache.org/io/

　　下载：commons-io-1.4-bin.zip       得到：commons-io-1.4.jar

2.表单的属性设置和使用File控件选择文件

 <form enctype="multipart/form-data" action="test.jsp" method="post">
    姓名:<input type="text" name="username">
    选择图片:<input type="file" name="myfile">
    <input type="submit" value="提交">
    </form>

from标签上的method的属性必须取值为post，不能取值get

文件上传页面，代码所示：

<%@page import="java.io.File"%>
<%@page import="org.apache.commons.fileupload.FileItem"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload" %>
<%@page import="org.apache.commons.fileupload.disk.DiskFileItemFactory" %>
<%
   request.setCharacterEncoding("utf-8");
   boolean flag=ServletFileUpload.isMultipartContent(request);
   if(flag){
       DiskFileItemFactory factory=new DiskFileItemFactory();
       ServletFileUpload upload=new ServletFileUpload(factory);
      List<FileItem> fileList= upload.parseRequest(request);
      Iterator<FileItem> myitor= fileList.iterator();
      while(myitor.hasNext()){
          FileItem item=myitor.next();
          if(item!=null){
              if(item.isFormField()){
                  String name=item.getFieldName();
                  if(name.equals("username")){
                      out.print(item.getString("utf-8"));
                  }
              }else{
                 String fileName= item.getName();
                 String path="/WEB-INF/upload/";
                 String abosolutePath= this.getServletContext().getRealPath(path);
                 File file=new File(fileName);
                 File uploadFile=new File(abosolutePath,file.getName());
                 item.write(uploadFile);
                 out.print("上传成功");
                 
              }
          }
      }
   }
%>

 web界面：