Binary file techniques

Question

I have searched through many forums and faq's on this subject. Some say you can retrieve a blob from the database and display it on the screen some say you can't. I have been experimenting with this and I have a jsp page that is trying to do that job. I think I am nearly there but I have an error : java.sql.SQLException: [Microsoft][ODBC Driver Manager] Function sequence error. Can anyone shed some light on this situation as I believe it can be done!
I have included my code
Connection con = null;
     String shortname = null;
     String From=request.getParameter("From");
     String CusRef=request.getParameter("CusRef");
     if(From==null)
          out.println("You must enter the information -From- ");
     if(CusRef==null)
          out.println("You must enter the information -Customer Reference- ");
     try
          Class.forName(Dsn);     
          con = DriverManager.getConnection(url);
          Statement cstmt = con.createStatement();
          String sql="SELECT FileName From Table1 WHERE From='" + From + "' And CusRef = '" + CusRef + "'";
          java.sql.ResultSet rs = cstmt.getResultSet();
          while ( rs.next() )
               Blob f = rs.getBlob(1);
               InputStream in = new BufferedInputStream(f.getBinaryStream());
               //InputStream in = new FileInputStream(f);
               ServletOutputStream outs = response.getOutputStream();
               int bufferSize = 4096;
               byte[] ioBuffer = new byte[bufferSize];
               byte[] lastBuffer; // last buffer
               long counter = 0; // how many bytes we have gotten through
               long fileSize = f.length();
               System.out.println(fileSize);
               response.setHeader("Content-Disposition", "attachment;filename=" + shortname);
               response.setContentType("application/download");     
               out.clearBuffer();
               while (fileSize > (counter + bufferSize))
                    in.read(ioBuffer);
                    outs.write(ioBuffer);
               counter += bufferSize;
               // add final chunk if the fileSize does not happen to be divisible by the bufferSize
               if (fileSize > counter)
                    lastBuffer = new byte[ (int) (fileSize - counter) ];
                    in.read(lastBuffer);
                    outs.write(lastBuffer);
               outs.flush();
               outs.close();
               in.close();
     catch(Exception e)
          System.out.println(e);

Answer 1

Since making the changes appropriately that you have suggested I now have two errors. Here is my code as it stands and my two errors.
code
Class.forName(Dsn);     
          con = DriverManager.getConnection(url);
          Statement cstmt = con.createStatement();
          //String sql ="SELECT To From Table1 WHERE From='" + From + "' And CusRef = '" + CusRef + "'";
          String sql="SELECT FileName From Table1 WHERE From='" + From + "' And CusRef = '" + CusRef + "'";
          java.sql.ResultSet rs = cstmt.getResultSet();
          //System.out.println(rs);
          long lngTime = System.currentTimeMillis();
          boolean blnTest = false;
          while((!blnTest) && (System.currentTimeMillis() < lngTime + 2000))
               blnTest = rs.next();
               while ( blnTest )
                    Blob f = rs.getBlob(1);
                    System.out.println("Test ");
                    byte[] BlobContent = null;
                    BlobContent = rs.getBytes(1);
                    InputStream in = new BufferedInputStream(BlobContent.getBinaryStream());
                    ServletOutputStream outs = response.getOutputStream();
                    int bufferSize = 4096;
                    byte[] ioBuffer = new byte[bufferSize];
                    byte[] lastBuffer; // last buffer
                    long counter = 0; // how many bytes we have gotten through
                    long fileSize=0;
                    fileSize = BlobContent.length();
                    System.out.println(fileSize);
                    response.setHeader("Content-Disposition", "attachment;filename=" + shortname);
                    response.setContentType("application/download");     
                    out.clearBuffer();
                    while (fileSize > (counter + bufferSize))
                         in.read(ioBuffer);
                         outs.write(ioBuffer);
                    counter += bufferSize;
                    // add final chunk if the fileSize does not happen to be divisible by the bufferSize
                    if (fileSize > counter)
                         lastBuffer = new byte[ (int) (fileSize - counter) ];
                         in.read(lastBuffer);
                         outs.write(lastBuffer);
                    outs.flush();
                    outs.close();
                    in.close();
     catch(Exception e)
          System.out.println(e);
and my two errors
An error occured between lines: 19 and 100 in the jsp file: /CAR/Select.jsp
Generated servlet error:
F:\Tomcat\work\localhost\_\CAR\Select$jsp.java:155: Method getBinaryStream() not found in class java.lang.Object.
                    InputStream in = new BufferedInputStream(BlobContent.getBinaryStream());
                    ^
An error occured between lines: 19 and 100 in the jsp file: /CAR/Select.jsp
Generated servlet error:
F:\Tomcat\work\localhost\_\CAR\Select$jsp.java:163: Method length() not found in class java.lang.Object.
                    fileSize = BlobContent.length();
                    ^
2 errors
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