BLOB download from table

Question

Hello everybody,
I am newbie here and not very experienced with JSF. :)
I have a mySQL database with different kind of data in it. My web application displays the results of a SELECT directly on the browser via a table; some of the fields contain BLOB (pdf) objects that are displayed as an alphanumeric string: my idea would be to have something like a link to download the blob instead!
Is there a JSF solution to my problem?
Thanks!

Answer 1

This is what I did
In my JSF page
< h:graphicImage height="262" width="350" url="#{img.imgurl}"/>
The call a servlet to display the BLOB image code below
public class ImageBean {
     private String imgurl;     
     public ImageBean(String incidentid, String image_id){
     this.imgurl = "/faces/dispImage?fieldhh_inspectionid="+incidentid+"&pictures="+image_id;
     public void setImgurl( String imgurl){
          this.imgurl = imgurl;
     public String getImgurl(){
          return(imgurl);
} // end class
My Servlet Stuff
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import oracle.sql.BLOB;
public class dispImage extends HttpServlet {
     ServletConfig svconfig = getServletConfig();
     Connection connection_mysql = null;
     protected void doPost(HttpServletRequest request,
                                                  HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
int t_number = 0;
int image_number = 0;
ServletOutputStream out = response.getOutputStream();
t_number = Integer.parseInt(request.getParameter("fieldhh_inspectionid"));
image_number = Integer.parseInt(request.getParameter("pictures"));
response.setContentType("image/jpeg");
     byte[] bytes = null;
     Blob blob = null;
     ServletContext context = getServletContext();
     String mysql_driver =context.getInitParameter("jdbcDriver");
     String user = context.getInitParameter("username");
     String password = context.getInitParameter("password");
     String dbURL =context.getInitParameter("dbUrl")+"?user="+user+"&password="+password;
     try{
     Class.forName(mysql_driver);
     Statement stmt = null;
     ResultSet rset = null;
     connection_mysql = DriverManager.getConnection(dbURL);
     connection_mysql.setAutoCommit( false );
     stmt = connection_mysql.createStatement();
          String selString = "select image from images where incidentid = "+t_number+" and image_id ="+image_number;
          byte [] image;     
          rset = stmt.executeQuery(selString);
          while(rset.next()){
          blob = rset.getBlob(1);     
bytes = blob.getBytes(1,(int)blob.length());
          out.write(bytes);
          out.flush();
          out.close();
     } // end try
     catch(Exception e){
     e.printStackTrace();
     e.getMessage();
} // end of doGet
public byte[] getBlob(int tfir_num, int image) {
byte[] bytes = null;
     ServletContext context = getServletContext();
     Blob blob = null;
     try{
     Statement stmt = null;
     ResultSet rset = null;
     stmt = connection_mysql.createStatement();
     String selString = "select image from images where incidentid = "+tfir_num;
          rset = stmt.executeQuery(selString);
     while(rset.next()){
          blob = rset.getBlob(1);
rset.close();
bytes = blob.getBytes(1, (int)(blob.length() ));
          connection_mysql.close();
     } // end try
     catch(Exception e){
     e.printStackTrace();
     e.getMessage();
//     System.out.println("DONE returning byte");
     return(bytes);
}// end dispImage class