文件上传

最新推荐文章于 2024-02-18 14:17:11 发布

与世无争的程序猿

最新推荐文章于 2024-02-18 14:17:11 发布

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本文链接：https://blog.youkuaiyun.com/qq_38487054/article/details/79620032

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文件上传

项目结构

1.前端页面

<!DOCTYPE html>

<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="/FileUpload/fileuploadServlet2" method="post" enctype="multipart/form-data">
        <input type="text" name="username"><br>
        <input type="file" name="filename"><br>
        <input type="submit" value="上传">
    </form>
</body>

</html>

2.servlet

public class FileuploadServlet2 extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       //1创建磁盘文件工厂--
       //作用设置缓存文件大小设置临时文件存储的位置
       String path_temp=this.getServletContext().getRealPath("temp");
       //DiskFileItemFactory factory=new DiskFileItemFactory(1024*1024,new File(path_temp));
       DiskFileItemFactory factory=new DiskFileItemFactory();
       factory.setSizeThreshold(1024*1024);
       factory.setRepository(new File(path_temp));
       //2创建文件上传的核心类
       ServletFileUpload upload=new ServletFileUpload(factory);
       //设置上传文件的名称的编码
       upload.setHeaderEncoding("UTF-8");
       //ServletFileUpload的api
       boolean multipartContent = upload.isMultipartContent(request);//判断表单是否是文件上传表单
       if(multipartContent){
           //是文件上传表单
           //***解析request获得文件项集合
           try {
               List<FileItem> parseRequest = upload.parseRequest(request);
               if(parseRequest!=null){
                   for (FileItem fileItem : parseRequest) {
                       //判断是不是一个普通表单项
                       boolean formField = fileItem.isFormField();
                       if(formField){
                           //username=zhangsan
                           String fieldName = fileItem.getFieldName();
                           String fieldValue = fileItem.getString("UTF-8");//对普通表单项的内容进行编码
                           System.out.println(fieldName+"--"+fieldValue);

                           //当表单是 enctype="multipart/form-data" 时request.getParameter相关的方法都失效
                           //String parameter=request.getParameter("username");
                       }else{
                           //文件上传项
                           //文件名
                           String fieldName = fileItem.getName();
                           //获得上传文件的内容
                           InputStream in = fileItem.getInputStream();
                           String path_store=this.getServletContext().getRealPath("upload");
                           OutputStream out=new FileOutputStream(path_store+"/"+fieldName);
                           IOUtils.copy(in, out);
                           in.close();
                           out.close();
                           //删除临时文件
                           fileItem.delete();
                       }
                   }
               }
           } catch (FileUploadException e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
           }
       }else{
           //不是文件上传表单
           //使用原始的表单数据获取方式request.getParameter();
       }
   }

   public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       doGet(request, response);
   }
}