public static void main(String[] args) throws Exception {
//get the instance of the IClient interface
client = ClientFactory.getDefaultInstance();

setSystemListener();
tryToConnect();
subscribeToInstruments();

//i need to place a market order here... how to get handle on iorder here?
//i have attached the file also


}

    public static void main(String[] args) throws Exception {
        //get the instance of the IClient interface
        client = ClientFactory.getDefaultInstance();

        setSystemListener();
        tryToConnect();
        subscribeToInstruments();

        LOGGER.info("Starting strategy");
        client.startStrategy(new MyStrategy());
    }

In your strategy you program all logic responsible for placing/closing orders. Then you pass your strategy in startStrategy() method as a parameter.