How to get value of 'CARBON_HOME' in java code

I was trying to implement an Axis2 service that receives user requests and publishes them as events to a CEP using carbon databridge thrift (via 'org.wso2.carbon.databridge.agent.thrift.DataPublisher')

I followed the code sample provided in wso2cep-3.1.0/samples/producers/activity-monitor

please see the following code snippet

public class GatewayServiceSkeleton{

        private static Logger logger = Logger.getLogger(GatewayServiceSkeleton.class);


        public RequestResponse request(Request request)throws AgentException,
                    MalformedStreamDefinitionException,StreamDefinitionException,
                    DifferentStreamDefinitionAlreadyDefinedException,
                    MalformedURLException,AuthenticationException,DataBridgeException,
                    NoStreamDefinitionExistException,TransportException, SocketException,
                    org.wso2.carbon.databridge.commons.exception.AuthenticationException
            {

               final String GATEWAY_SERVICE_STREAM = "gateway.cep";
               final String VERSION = "1.0.0";
               final String PROTOCOL = "tcp://";
               final String CEPHOST = "cep.gubnoi.com";
               final String CEPPORT = "7611";
               final String CEPUSERNAME = "admin";
               final String CEPPASSWORD = "admin";

               Object[] metadata = { request.getDeviceID(), request.getViewID()};
               Object[] correlationdata = { request.getSessionID()};
               Object[] payloaddata = {request.getBucket()};


               KeyStoreUtil.setTrustStoreParams();

               KeyStoreUtil.setKeyStoreParams(); 


               DataPublisher dataPublisher = new DataPublisher(PROTOCOL + CEPHOST + ":" + CEPPORT, CEPUSERNAME, CEPPASSWORD);

                 //create event 
               Event event = new Event (GATEWAY_SERVICE_STREAM + ":" + VERSION, System.currentTimeMillis(), metadata, correlationdata, payloaddata);

                 //Publish event for a valid stream

               dataPublisher.publish(event);
                 //stop 
               dataPublisher.stop();


                RequestResponse response = new RequestResponse();
                response.setSessionID(request.getSessionID());
                response.setDeviceID(request.getDeviceID());
                response.setViewID(request.getViewID());
                response.setBucket(request.getBucket());
                return response; 

            }

there is also a utility class that set the key store parameters as following

public class KeyStoreUtil {

    static  File filePath = new File("../../../repository/resources/security");

    public static void setTrustStoreParams() {
        String trustStore = filePath.getAbsolutePath();
        System.setProperty("javax.net.ssl.trustStore", trustStore + "/client-truststore.jks");
        System.setProperty("javax.net.ssl.trustStorePassword", "wso2carbon");

    }

    public static void setKeyStoreParams() {
        String keyStore = filePath.getAbsolutePath();
        System.setProperty("Security.KeyStore.Location", keyStore + "/wso2carbon.jks");
        System.setProperty("Security.KeyStore.Password", "wso2carbon");

    }
}

I uploaded the service into a wso2as-5.2.1, and called the service using SOAPUI

the request returned an error message "cannot borrow client for TCP"

I debug, and found out the problem might lies with the class 'KeyStoreUtil',

where the 'filePath' somehow retuned a 'null',

static  File filePath = new File("../../../repository/resources/security");

and caused the failure on this line

DataPublisher dataPublisher = new DataPublisher(PROTOCOL + CEPHOST + ":" + CEPPORT, CEPUSERNAME, CEPPASSWORD);

I guess it could be a better idea if I use the value of "CARBON_HOME" to figure out the location of Key Store

so my question is :

How may I be able to get the value of 'CARBON_HOME' in the Java code?

that said. If you think a bit more: the service will be called numerous time; whileas the 'setTrustStoreParams' and the 'setKeyStoreParams' will only be needed to executed once at the server/service initiate.

So, are there any even better ways to remove 'setTrustStoreParams' and 'setKeyStoreParams' out of the service code, or implement as configurable items?

Please advise

thanks

so my question is :

How may I be able to get the value of 'CARBON_HOME' in the Java code?

You should use the property carbon.home like following which will retrieve the WSO2 product's home directory.

System.getProperty("carbon.home");