how to pass a proxy?

 jdev version: 10.1.2.3.0
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - Prod
PL/SQL Release 10.2.0.4.0 - Production
TNS for Linux: Version 10.2.0.4.0 - Production

Hello,

i've follow a tutorial to make a client to consume e web service in forms.
i must work through a proxy server.

here is the jdev code:

public class PrimeNumbersStubnew extends WrappedDocLiteralStub  
{
public PrimeNumbersStubnew()
{
m_httpConnection = new OracleSOAPHTTPConnection();
Properties props = new Properties();
props.put(OracleSOAPHTTPConnection.PROXY_HOST, "10.0.2.21");
props.put(OracleSOAPHTTPConnection.PROXY_PORT, "8070");
props.put(OracleSOAPHTTPConnection.PROXY_AUTH_TYPE, "basic");
props.put(OracleSOAPHTTPConnection.PROXY_USERNAME, "XXXXX");
props.put(OracleSOAPHTTPConnection.PROXY_PASSWORD, "XXXXX");
m_httpConnection.setProperties(props);
}

private String _endpoint = "