Hello @Ashish Gupta,

In Developer Guide for your language option, for example OpenDacs - Java Development Guides look up AuthorizationAgent -> getPEList().

If you are just starting with OpenDACS I would suggest to first work through OpenDACS QuickStart Guide and OpenDACS Tutorials (I include likes to Java, the exact same materials can be found in C++ and .Net),

as together, these materials give a working understanding of the fundamentals of OpenDACS API.

Hope this helps

Hello @Ashish Gupta

You can modify DacsSubscribeClient.java to get the list of services on DACS as example snipped source code below:

  private Vector<AuthorizationServiceAttributes> _getServiceAttributes() {
        try  {
            // AuthorizableServiceAttributes is an instance for keeping 
            // attributes information of an authorizable service.
            Vector<AuthorizationServiceAttributes> services = new Vector<AuthorizationServiceAttributes>();
            /*
             * Pass the vector of AuthorizableServiceAttribute instances as 
             * a parameter of the AuthorizationAgent's getServiceAttributes()
             * method.It will be pushed the attributes of all authorizable 
             * services within that method.
             */
            AuthorizationCheckResult authCheckResult = _agent.getServiceAttributes(services);
            // Check the result of calling the getServiceAttributes() method.
            if (authCheckResult == AuthorizationCheckResult.ACCESS_ALLOWED) {
                // Calling the method success.
                return services;
            } else {
                // Calling the method failed, return null.
                return null;
            }
        } catch (AuthorizationException ae) {
            System.err.println("AuthorizationAgent.getServiceAttributes() failed");
            return null;
        }
    }

Then, check if the user is entitled to each service.

public void checkAuthorizableServices() {
        Vector<AuthorizationServiceAttributes> services = _getServiceAttributes();
        if (services != null) {
            System.out.println("Connected DACS server has " + services.size()
                    + " authorizable service(s)");
            for (int i = 0; i < services.size(); i++) {
                AuthorizationServiceAttributes attrs = services.get(i);
                System.out.println("#" + (i + 1) + "#");
                System.out.println("  Service   ID: "
                        + attrs.getServiceId());
                System.out.println("  Service Name: "
                        + attrs.getServiceName());
                System.out.println("  Service Type: "
                        + attrs.getServiceType());
                System.out.println("  Service  Qos: "
                        + attrs.getServiceQoS());
                 AuthorizationCheckStatus authCheckStatus = new AuthorizationCheckStatus();
                 try {
                     AuthorizationCheckResult     authCheckResult = _agent.checkSubscription(_handle, _usage, _reqtype,
                         authCheckStatus,services.get(i).getServiceName());
                     if (authCheckResult == AuthorizationCheckResult.ACCESS_ALLOWED) {
                         System.out.println("[" + _daemonHost + "] " + _name +
                          " allowed subscription access to service " + services.get(i).getServiceName());
                     }
                     else {
                         System.out.println("[" + _daemonHost + "] " + _name +
                          " denied subscription access to service " + services.get(i).getServiceName());
                         System.out.println("status message - " +
                          authCheckStatus.getStatusText());
             }
   } catch (AuthorizationException ae) {
     // In case the exception occurs during calling method.
     System.err.println("[" + _daemonHost + "] " + _name +
                        " check subscription service  " + services.get(i).getServiceName() +
                        " failed");
           }
            }
        }
}

The example output: