Eligible for garbage collection?

Question

I know that an instance of an inner class must bind to an instance of the wrapper class and this lead me to question what happens to a wrapper class instance, when there is no reference to it but when there is still a reference to a bound instance.

So, is object referenced by otr eligible for garbage collection once the reference is set to null ?

class Outer
{
    class Inner
    {

    }
}

class Test{
    public static void main(String []args){
        Outer otr = new Outer() ;           // (1)
        Outer.Inner oi = otr.new Inner() ;  // (2)
        otr = null ;                        // (3)
        // more complicated code
    }
}

The rules for a class are fundamentally no different than for any other object -- they can be released when they are no longer (strongly) reachable. (But note that "not reachable" is not the same as "having no references to it".) — Hot Licks
Therefore the wrapper instance is still reachable through the instance of the inner class that is bound to it ? Making it not eligible for collection ? — user9349193413
As a general rule, unless you're mucking around with "weak" references or "unsafe" or some such, just assume that GC is magic and it works and you don't have to think about it. — Hot Licks

Brett Okken Brett Okken · Accepted Answer · 2014-06-30T15:15:50

As you stated the (non-static) inner class has an (implicit) reference to the outer class instance used to create it. Therefore the instance of the outer class cannot be garbage collected until the instance of the inner class is no longer (strongly) referenced.

Eligible for garbage collection?

3 Answers