循环依赖

1.

public class Test {
    public static void main(String[] args) {
        AAA aaa = new AAA();
    }
}
class AAA{
    BBB bbb = new BBB();
}
class BBB{
    AAA aaa= new AAA();
}

Exception in thread "main" java.lang.StackOverflowErro

2.

public class Test {
    public static void main(String[] args) {
        AAA aaa = new AAA();
    }
}
class AAA{
    BBB bbb;
}
class BBB{
    AAA aaa;
}

3

public class Test {
    public static void main(String[] args) {
        AAA aaa = new AAA();
    }
}
class AAA{
    BBB bbb = new BBB();
}
class BBB{
    AAA aaa;
}

4

public class Test {
    public static void main(String[] args) {
        AAA aaa = new AAA();
    }
}
class AAA{
    static BBB bbb = new BBB();
}
class BBB{
    AAA aaa = new AAA();
}