uploading of pdf file

 

i want to upload a pdf file by using code given below.It give browsing facility but dont upload file. When i click sendfile button Its display uploadfile.html code page. How can i do that??? where is the error in the given code???

filename-upload.html 

<%@ page language="java" %>
<HTml>
<HEAD><TITLE>Display file upload form to the user</TITLE></HEAD>  
<% //  for uploading the file we used Encrypt type of multipart/
form-data and input of file type to browse and submit the file %>
  <BODY> <FORM  ENCTYPE="multipart/form-data" ACTION=
"uploadfile.html" METHOD=POST>
        <br><br><br>
      <center><table border="2" >
                    <tr><center><td colspan="2"><p align=
"center"><B>PROGRAM FOR UPLOADING THE FILE</B><center></td></tr>
                    <tr><td><b>Choose the file To Upload:</b>
</td>
                    <td><INPUT NAME="F1" TYPE="file"></td></tr>
                    <tr><td colspan="2">
<p align="right"><INPUT TYPE="submit" VALUE="Send File" ></p></td></tr>
             <table>
     </center>      
     </FORM>
</BODY>
</HTML>

filename--uploadfile.html 

<%@ page import="java.io.*" %>
<%
    //to get the content type information from JSP Request Header
    String contentType = request.getContentType();
    //here we are checking the content type is not equal to Null and
 as well as the passed data from mulitpart/form-data is greater than or
 equal to 0
    if ((contentType != null) && (contentType.indexOf("multipart/
form-data") >= 0)) {
        DataInputStream in = new DataInputStream(request.
getInputStream());
        //we are taking the length of Content type data
        int formDataLength = request.getContentLength();
        byte dataBytes[] = new byte[formDataLength];
        int byteRead = 0;
        int totalBytesRead = 0;
        //this loop converting the uploaded file into byte code
        while (totalBytesRead < formDataLength) {
            byteRead = in.read(dataBytes, totalBytesRead, 
formDataLength);
            totalBytesRead += byteRead;
            }

        String file = new String(dataBytes);
        //for saving the file name
        String saveFile = file.substring(file.indexOf("filename=
"") + 10);
        saveFile = saveFile.substring(0, saveFile.indexOf("n"));
        saveFile = saveFile.substring(saveFile.lastIndexOf("")
 + 1,saveFile.indexOf("""));
        int lastIndex = contentType.lastIndexOf("=");
        String boundary = contentType.substring(lastIndex + 1,
contentType.length());
        int pos;
        //extracting the index of file 
        pos = file.indexOf("filename="");
        pos = file.indexOf("n", pos) + 1;
        pos = file.indexOf("n", pos) + 1;
        pos = file.indexOf("n", pos) + 1;
        int boundaryLocation = file.indexOf(boundary, pos) - 4;
        int startPos = ((file.substring(0, pos)).getBytes()).length;
        int endPos = ((file.substring(0, boundaryLocation))
.getBytes()).length;

        // creating a new file with the same name and writing the 
content in new file
        FileOutputStream fileOut = new FileOutputStream(saveFile);
        fileOut.write(dataBytes, startPos, (endPos - startPos));
        fileOut.flush();
        fileOut.close();

        %><Br><table border="2"><tr><td><b>You have successfully
 upload the file by the name of:</b>
        <% out.println(saveFile); %></td></tr></table> <%
        }
%>

This is clearly a Roseindia code snippet. First of all, it is the worst learning resource ever. Don't use it. It only teaches bad practices. Add that site to your blacklist. In fact, any "tutorial" site which is littered with advertisement banners and hopelessly outdated low quality code snippets are clearly maintained by amateurs with primary focus on advertisement income instead of on serious teaching. Other examples of such crap "tutorial" sites are javabeat, tutorialspoint, journaldev, javatpoint, etc. Remarkable common thing which those sites have is that they are originated in India.

Apart from the fact that you incorrectly used .html file extension instead of .jsp (even though they presented their examples correctly with .jsp extensions), there are several major problems with the code snippet:

  • The HTML is using '90s style uppercased tags. This is discouraged.
  • The HTML is using <font> and <center> tags which are deprecated since 1998.
  • The business logic is mingled with the presentation logic in a single JSP file. The Java code belongs in a Java class, not in a JSP file.
  • The parser is relying on Content-Length request header which is not always present per se. If this header is absent, the code breaks.
  • The parser is creating a byte array of that length. This may crash the server when the content length is larger than available server memory.
  • The parser is creating a String based on the byte array using server platform default character encoding instead of the one specified in multi part header. This may malform/corrupt the result bytes.
  • The DataInputStream wrapper is unnecessary, the code is not taking any benefit of it.
  • Etc..
  • Etc..

    • It's simply terrible.

    The right way to upload a file from JSP is to submit the form to a @MultipartConfig annotated servlet class and then use request.getPart() to get the file. You can find a snippet in this answer: How to upload files to server using JSP/Servlet?

    The right way to learn Java EE is elaborated in this answer: Java EE web development, where do I start and what skills do I need?

    链接地址: http://www.djcxy.com/p/46208.html

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