CODE EXAMPLE FOR JAVA

how-to-use-volley-string-request-in-android

public class LoginRequest extends Request<String> {

    // ... other methods go here

    private Map<String, String> mParams;

    public LoginRequest(String param1, String param2, Listener<String> listener, ErrorListener errorListener) {
        super(Method.POST, "http://test.url", errorListener);
        mListener = listener;
        mParams = new HashMap<String, String>();
        mParams.put("paramOne", param1);
        mParams.put("paramTwo", param2);

    }

    @Override
    public Map<String, String> getParams() {
        return mParams;
    }
}