Re: JDBC + PostgreSQL + LargeObjects

I would just change this:

...
int i=0;
for(i=0; i<obj.size() ; i++)
{
out.write(buf[i]);
}
...

to this:

...
out.write(buf);
out.flush();
out.close();
...

Writing it out 1 byte at a time would be way too inefficient and is
probably why your CPU pegs.

Cheers,

Marc

Paulo Delgado wrote:

> Ok folks, now it works! thank you all! (i'm using a servlet to avoid the white spaces)
> Now i have another problem, when the servlet is writing the bytes to the outputstream, the cpu load increases to 100%, i guess the problem is in the for() block, should i look for another way of doing this? or use perl? or what?
>
> check it out:
>
> import javax.servlet.*;
> import java.io.*;
> import javax.servlet.http.*;
> import java.sql.*;
> import org.postgresql.largeobject.*;
>
> public class show_coctel extends HttpServlet
> {
> public void doGet(HttpServletRequest request , HttpServletResponse response) throws ServletException, IOException
> {
> ServletOutputStream out = response.getOutputStream();
> response.setContentType("image/jpeg");
> try
> {
> Class.forName("org.postgresql.Driver");
> }
> catch(ClassNotFoundException cnfex)
> {
> cnfex.printStackTrace();
> }
> try
> {
> Connection mycon;
> mycon= DriverManager.getConnection("jdbc:postgresql://localhost:5432/database", "username" , "password");
> mycon.setAutoCommit(false);
>
> // Get the Large Object Manager to perform operations with
> LargeObjectManager lobj = ((org.postgresql.Connection)mycon).getLargeObjectAPI();
> PreparedStatement ps = mycon.prepareStatement("SELECT pic FROM cocteles WHERE month='"+request.getParameter("m")+"' AND year="+request.getParameter("y"));
> ResultSet rs = ps.executeQuery();
> if (rs != null) {
> while(rs.next()) {
> //open the large object for reading
> int oid = rs.getInt(1);
> LargeObject obj = lobj.open(oid , LargeObjectManager.READ);
>
> //read the data
> byte buf[] = new byte[obj.size()];
> obj.read(buf, 0, obj.size());
>
> //do something with the data read here
> response.setContentLength(obj.size());
> int i=0;
> for(i=0; i<obj.size() ; i++)
> {
> out.write(buf[i]);
> }
> // Close the object
> obj.close();
> }
> rs.close();
> }
> ps.close();
> mycon.close();
> }
> catch(SQLException sqex)
> {
> out.println(sqex.toString());
> }
> }
> }
>
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>
>

--
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Marc P. Lavergne [wk:650-576-7978 hm:407-648-6996]
Senior Software Developer
Global Knowledge Management
Worldwide Support Technologies
Openwave Systems Inc.

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