Multithreaded sqlj problem

Question

i have a java class with some sqlj code. the application is multithreaded and several calls to an object of this class are performed. the problem is that the queriesDone-function does not work. the establishConnection-function works perfectly. why?
thanks.
code:
import sqlj.runtime.*;
import sqlj.runtime.ref.*;
import java.sql.*;
class PipeManager {
String mess = "";
int sendstat,status;
public PipeManager() {
ConnectionManager.initContext();
public String establishConnection() {
try {
#sql {
begin
:OUT status := dbms_pipe.receive_message('ALIVE');
dbms_pipe.unpack_message(:OUT mess);
end;
System.out.println("Mess: "+mess);
#sql {
begin
dbms_pipe.pack_message('hej jag lever!');
:OUT sendstat := dbms_pipe.send_message(:IN mess);
end;
System.out.println("Sendstat: "+sendstat);
#sql {
begin
:OUT status := dbms_pipe.receive_message('MEDIATOR');
dbms_pipe.unpack_message(:OUT mess);
end;
} catch (SQLException e) { e.printStackTrace(); }
return mess;
public void queriesDone(String pipe) {
try {
#sql {
begin
dbms_pipe.pack_message('KLAR!');
:OUT sendstat := dbms_pipe.send_message(:IN pipe);
end;
} catch (SQLException e) { e.printStackTrace(); }
}

Answer 1

In your code you are using the static default connection context. For a mutithreaded program each thread should have either its own ExecutionContext or its own ConnectionContext (the latter corresponds to a database connection).
Please see the SQLJ documentation at:
http://technet.oracle.com/doc/oracle8i_816/java.816/a81360/alangfe3.htm#1004410
There also is a demo MultiThreadDemo.sqlj.
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