spring - Injecting property using @Value to abstract class -

i have abstract class in trying use @value annotation inject value property file

public abstract class parent {      @value ("${shared.val}")      private string sharedval;       public parent() {         //perform common action using sharedval      }  }  @component public class childa extends parent {      param a1;      @autowired      public childa (param a1) {         super();         this.a1 = a1;      } } 

i getting nullpointerexception since sharedval not set. tried adding @component stereotype on abstract class , still same thing.

can inject value abstract class way? if not how can accomplish this?

i think you'll find sharedval is being set, you're trying use in constructor. constructor being called (must called) before spring injects value using @value annotation.

instead of processing value in constructor, try @postcontruct method instead, eg:

@postconstruct void init() {     //perform common action using sharedval  } 

(or alternatively, implement spring's initializingbean interface).