Java内部类访问另一个内部类中的变量

Question

My main Class has 2 inner class, 1 of them is thread, I don't know how my inner class 2 can access (Or how to know var1 is true or false) value of inner class 1, this is my example, thanks!

public class InnerClass  {
    public class InnerClass1 implements NativeKeyListener {
        public boolean var1;
    }

    public class InnerClass2 implements Runnable{

        @Override
        public void run() {
            while (true) {
                var1...
            }
        }

    }
}

Answer 1

You cannot access nonstatic variables/methods/inner classes unless you have instantiated the object (ie created an instance of the object ). You need an InnerClass1 object before you can store or get anything out of it. Until you do something like InnerClass1 foo = new InnerClass1() , there is no var1 anywhere.

Anyway, I think you are misusing inner classes. I'd suggest if you haven't already walking through the Java Tutorials Trail to get a basic idea of how classes, fields, and instantiation work in Java.

Answer 2

You can do it by an interface or class that is implemented by innerclass1. Try this:

public interface NativeKeyListener {
boolean a();
}

public class InnerClass {

static NativeKeyListener m() {
    class InnerClass1 implements NativeKeyListener {
        public boolean var1;

        public boolean a() {
            return var1;
        }
    }
    return new InnerClass1();
}

public class InnerClass2 implements Runnable {

    public void run() {
        NativeKeyListener i = InnerClass.m();
        i.a();
    }

}

}