/*This demo program explains the use of listener class  of advanced queueing in occi.This functionality  aims at listening on behalf of a bunch of agents which are specified on 1 or more queues, and return the agent for whom a message has arrived.The listen() call listens on one or more queues on behalf of a list of agents. This call returns the agent for which there is a message. Prior to this call, the list of agents on behalf to listen to must been set. This is a blocking call that returns when there is a message ready for consumption for an agent in the list. If there are no messages found when the wait time expires, an error is returned.*/#include<iostream>#include<occi.h>#include<vector>using namespace std;using namespace oracle::occi;using namespace oracle::occi::aq;void test_enqueue(Environment *env, Connection *conn){    cout<<"Enqueuing the message into the queue"<<endl;    Message m(env);    unsigned char by[] = "10001000";    int bylen = 8;    cout<<"Message before enqueue : ";    Bytes in(by, bylen, 0);    for (int k=0; k<bylen; ++k)      cout << by[k];    cout << endl;    m.setBytes(in);    Producer prod(conn);    prod.send(m, "hr.queue04");    conn->commit();    cout<<"Enqueue done"<<endl;}void test_listener(Environment *env, Connection *conn){    Listener l(conn);    vector<Agent> agList;    agList.push_back(Agent(env, "AGT1", "hr.queue04"));    agList.push_back(Agent(env, "AGT2", "hr.queue04"));    // The listener is to listen for the above 2 agents.    l.setAgentList(agList);    l.setTimeOutForListen(10);    cout<<"Listening..."<<endl;    // As soon as a message intended for any of the above agents    // arrives at the queues being listened to, the listen call returns    // with the agent for whom the message is intended for.  In this case    // it is the agent(AGT1,"hr.queue04",0) since this is a subscriber    // to the hr.queue04. The enqueuer can also specify the recipients    // which will override the default subscriber list.    Agent a=l.listen();    cout<<"Message is for the following Agent: "<<endl;    string aname=a.getName();    string aadd=a.getAddress();    int aprot=a.getProtocol();    cout<<"name:"<<aname<<endl;    cout<<"address:"<<aadd<<endl;    cout<<"protocol:"<<aprot<<endl;    //create a consumer object using the agent.    Consumer cons(conn, a);    cons.setWaitTime(20);    // Need not specify consumer name and queuename.     // Will be inferred from the agent    cout<<"Dequeuing of the message"<<endl;    Message m2 = cons.receive(Message::RAW);    Bytes out = m2.getBytes();    cout << "Message after dequeue : ";    int length = out.length();    unsigned char *c = new unsigned char [length];    memset (c, 0, length);    out.getBytes(c, length, 0, 0);    for (int k=0; k<length; ++k)      cout << c[k];    cout << endl;    cout<<"Dequeue done"<<endl;    delete[] c;}int main(){   cout<<"Demo for advanced queueing listener"<<endl;   Environment *env = Environment::createEnvironment(Environment::OBJECT);   try   {      Connection *con = env->createConnection("HR","HR");      test_enqueue(env, con);      test_listener(env, con);      env->terminateConnection(con);   }   catch(SQLException &ex)   {     cout<<"Exception thrown "<<endl;     cout<<"Error number: "<<  ex.getErrorCode()<<endl;     cout<<ex.getMessage() << endl;   }   Environment::terminateEnvironment(env);   cout<<"Demo for advanced queueing listener done"<<endl;}