CODEWITHSUNDEEP
javajsp
gymcode
gymcode

Reputation: 4623

Serving PDF files from a Database via a JSP

Im doing a .PDF download code for Java. I am meeting a problem whereby I am able download the .PDF formatted file. The size of the file was correct, but when I open the .PDF file, it is empty inside. Any solution?

<%@ page import="java.io.*,java.util.*,java.sql.*"%>
<%
    int id = 0;
    if (request.getParameter("id") != null && request.getParameter("id") != "")
    {
        id = Integer.parseInt(request.getParameter("id").toString());
    }

    String connectionURL = "jdbc:mysql://localhost:3306/MajorProjectDB";
    String url = request.getParameter("WEB_URL");
    String Content = new String("");
    Statement stmt = null;
    Connection con = null;

    try
    {
        String filename = "data" + id + ".pdf";
        Class.forName("com.mysql.jdbc.Driver").newInstance();
        con = DriverManager.getConnection(connectionURL, "cdsadmin2", "enjoyit");
        stmt = con.createStatement();
        String qry = "select * from paper where PAPER_ID=" + id;
        ResultSet rst = stmt.executeQuery(qry);
        if (rst.next())
        {
            Content = rst.getString("Paper_Data");
        }
        out.println(Content);
        byte requestBytes[] = Content.getBytes();
        ByteArrayInputStream bis = new ByteArrayInputStream(requestBytes);
        response.reset();
        response.setContentType("application/pdf");
        response.setHeader("cache-control", "no-cache");
        response.setHeader("Content-disposition", "attachment; filename=" + filename);

        byte[] buf = new byte[1024];
        int len;
        while ((len = bis.read(buf)) > 0)
        {
            response.getOutputStream().write(buf, 0, len);
        }
        bis.close();
        response.getOutputStream().flush();
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
%>

Upvotes: 2

Views: 6873

Answers (2)

Joachim Sauer
Joachim Sauer

Reputation: 308001

Don't handle binary data using String!

If you do it you can badly mangle the binary data in a way that might make it un-retrievable (and even if it's retrievable, it will be complicated and very fragile).

You should use ResultSet.getBinaryStream() to get your PDF data from the database (assuming it's stored in a column in the appropriate type!).

Then simply read from the InputStream and write to the response as bytes, don't do any conversion to char[] or String in between!

Upvotes: 4

Rakesh
Rakesh

Reputation: 4334

why are you writing response.getOutputStream().write(buf, 0, len); inside the loop ?? instead create an OutputStream Object outside the while loop and use it. May be this might help. Something like 

 BufferedOutputStream bOut = response.getOutputStream();
 while ((len = bis.read(buf)) > 0){
            bOut.write(buf, 0, len);
        }
        bis.close();
        bOut.flush();

Upvotes: 0

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