Is it possible to create object of an inner class inside a static class in java?

Question

How can I declare an object of an inner class inside a static class in java?

public class xyz
{
    static class abc
    {
        ...
        // I want to declare an object of class a here. how can I do this?

    }
    class a
    {
        ...
    }
}

Perhaps [this](http://stackoverflow.com/questions/5272957/problem-creating-object-of-inner-class-in-java) is relevant. — juanpa.arrivillaga, Apr 24 '17 at 19:39
It's a little confusing at first, but like all non-static members, they have to be accessed through an instance. So you need to make a `xyz` object in `abc`. — juanpa.arrivillaga, Apr 24 '17 at 19:44
If you need an instance of `a` without an instance of `xyz`, you probably have a design flaw. Can you explain *why* you want this? — shmosel, Apr 24 '17 at 19:46
I am trying to make a file explorer using design pattern in java swing. I have to make only one object of class 'abc'. class 'abc' has the main 'frame'. class 'a' will have 'tree' of all directories. i need to add the 'tree' in that 'frame'. — jef, Apr 24 '17 at 20:02

score 2 · Answer 1 · edited Apr 24 '17 at 20:10

2

Instances of inner classes exist in the context of an instance of the enclosing class. So you must first create an instance of the enclosing class, and from there you can create an instance of the inner class. For example:

public class xyz {
    static class abc {
        a member = new xyz().new a();
    }

    class a {
    }
}

More information: Oracle Java Tutorials - Nested Classes

edited Apr 24 '17 at 20:10

user207421

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answered Apr 24 '17 at 19:51

Jesper

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I've tried this way, but it shows an error. It's asks me to create method a() inside class'abc'. – jef Apr 24 '17 at 20:04
'Non-static inner' is a tautology. See JLS #8.1.3. – user207421 Apr 24 '17 at 20:10

Is it possible to create object of an inner class inside a static class in java?

1 Answers1