I am trying to create a java application that can send HTTP requests and is connected to a database using Jersey framework. I have written the DAO,Service and Controller classes but I am getting this error “java.lang.NullPointerException: Cannot invoke “com.Service.getById(String)” because “this.Service” is null.

I have used @inject annotation to create the object of the service class and used @singleton annotation for the service class. But i am unable to resolve the error .