Spring bean stackoverflow error

Question

Suppose I have two classes

Class A

Class B

Now, Class A has dependency on Class B and Class B has dependency on class B.

Looks like

class A {
 private B b;
    public A(B b) {
    this.b = b;
    } 
}

class B {
 private A a;
    public B(A a) {
    this.a = a;
    }
}

The bean configuration for the same will be

@Bean 
public A getA() {
return new A(getB());
}

@Bean 
public B getB() {
return new B(getA());
}

This code results in a deadlock situation as one depeneds on the other. How to instantiate Beans in such case?

check out this link http://stackoverflow.com/questions/3485347/circular-dependency-in-spring — Avinash Reddy, Mar 23 '17 at 11:24
Possible duplicate of [Circular dependency in spring](http://stackoverflow.com/questions/3485347/circular-dependency-in-spring) — buræquete, Mar 23 '17 at 11:39

score 1 · Answer 1 · edited May 23 '17 at 12:25

1

Try using setter based dependency injection. Topic had also been discussed at Circular dependency in spring

edited May 23 '17 at 12:25

Community

1
1

answered Mar 23 '17 at 11:25

Marcin Tarka

56
4

score 1 · Answer 2 · answered Mar 23 '17 at 11:57

Other option is to use @PostConstruct annotation. In the answer proposed by Plog ypu have a problem that initialization of A is done in init method of B. With postConstruct, you can have a dedicated method resolveCircularDependencies.

Its just a cosmetic change, but makes it explicit why the wiring is done this way (which comes handy, when you forget about the existence of the cycle, or other programmer encounters the code).

@Bean 
public A getA(){
    return new A();
}

@Bean 
public B getB(){
    return new B();
}

@PostConstruct
public void resolveCircularDependencies() {
    getB().setA(getA());
    getA().setB(getB());
}

Spring bean stackoverflow error

2 Answers2