CODEWITHSUNDEEP
javaspringspring-bootautowired
Chinmay
Chinmay

Reputation: 364

Using Autowired object in

I am trying to understand how the Autowiring works in the SPringBoot. So, I had created a singketon class B [for example] and I was processing the instance of class B in class C and now want to use that in class A. It was all working fine. But, now I was told to use Auto wiring as my application is springBoot. So I did following

@Component
Class B{
 int track = 0;
}

Class C{
  @Autowired
  B b

  public void doSomething(){
  b.track = 1;
  }
}

Class A{
 // I want to use the object b in here for further processing, how can I do it ?
}

Am I doing it right ? Or How can I achieve this please ?

Upvotes: 0

Views: 45

Answers (1)

Bill Horvath
Bill Horvath

Reputation: 1717

For starters, you should consider using @Autowired on your constructors, as it lets you [avoid null pointer exceptions][1] if something isn't wired properly.

If you want to autowire B into A, do it the same way as you did with C; just make sure you avoid circular dependencies.

@Component
Class B{
 int track = 0;
}

Class C{
  private final B b;

  @Autowired
  public C(B b){
   this.b = b;
  }

  public void doSomething(){
   b.track = 1;
  }
}

Class A{
 private final B b;

 @Autowired
 public A(B b){
  this.b = b;
 }

}

[1]: http://evan.bottch.com/2009/02/03/setter-injection-sucks/ <- This is an oldie but a goodie; also see http://olivergierke.de/2013/11/why-field-injection-is-evil/

Upvotes: 1

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