JavaWeb文件上传与格式验证示例-优快云博客

登录页面：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>文件上传</title>
</head>
<body>   <form action="do_uplpad_show.jsp" method="post" enctype="multipart/form-data" >
   姓名:<input type="test"name="username"></br>
   性别：<input type="test"name="age"></br>
   文件上传：<input type="file"name="file"></br>
   <input type="submit"value="登录">
   </form>
</body>
</html>

处理页面：

<%@page import="java.util.ArrayList"%>
<%@page import="ch_06.User"%>
<%@page import="java.io.File"%>
<%@page import="org.apache.commons.fileupload.FileItem"%>
<%@page import="java.util.List"%>
<%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@page import="org.apache.commons.fileupload.FileItemFactory"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
   pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
   <%
       FileItemFactory fileItemFactory=new DiskFileItemFactory();
       //创建ServletFileUpload对象（上传文件核心对象）
       ServletFileUpload sfu=new ServletFileUpload(fileItemFactory);
       sfu.setSizeMax(1024*300);//限制图片大小限制300kb
       try{


       sfu.setHeaderEncoding("UTF-8");
       if(ServletFileUpload.isMultipartContent(request)){
           /*
           解析请对象
           通过集合来获取每一个表单项
           */

           List<FileItem>fileItems=sfu.parseRequest(request);
               for(FileItem fileItem:fileItems){
                   //判断fileItem对应的值表单控件是不是普通控件
                   if(fileItem.isFormField()){
                       //此处是普通表单数据
                   String fieldName=fileItem.getFieldName();
                   String value=fileItem.getString("UTF-8");
                   User user=new User();
                       if(fieldName.equals("username")){
                           user.setName(value);
                       }
                       if(fieldName.equals("age")){
                           user.setAge(value);
                       }
                   out.println(fieldName+"\t"+value);
                   }else{
                       /*
                       处理文件控件的逻辑
                       首先应该先得到文件上传到服务器的绝对路径
                       要用到application对象
                       */
                   String path= application.getRealPath("/uploadfile");//获取服务器上的文件写入到服务器上
                       out.println(path);
                       out.println(fileItem.getName());
                       //对于文件上传进行限制限制上船格式
                       //jpg png gif bmp
                       String fileName=fileItem.getName();
                              //截取字符串
                               Integer index=fileName.lastIndexOf(".");
                               //获取字符串下标
                           String houzhui =fileName.substring(index+1);
                               //后缀列表
                           List<String>houzhuiList=new ArrayList<>();
                           houzhuiList.add("jpg");
                           houzhuiList.add("png");
                           houzhuiList.add("gif");
                           houzhuiList.add("bmp");
                               if(houzhuiList.contains(houzhui)){
                                   fileItem.write(new File(path,fileItem.getName()));
                               }else{
                                   out.print("<script>");
                               out.print("alert('文件格式不支持请重新上传');");
                               out.print("history.go(-1);");
                               out.print("</script>");
                               }
                   }
               }
       }else{
           out.println("表单类型不支持文件上传");
       }
       }catch(Exception e){
           out.print("你上传文件已经超出无法上传最多只支持300kb");
       }
   %>
</body>
</html>

jsp文件上传