在Java中,当我不在内部类时,如何访问外部类？

OuterClass outer = new OuterClass();
outer.methodInOuterClass();

OuterClass.InnerClass.staticMethodInInnerClass();

int variable = OuterClass.InnerClass.staticVariableInInnerClass;

int constant = OuterClass.InnerClass.CONSTANT_IN_INNER_CLASS;

public class OuterClass {
    public class InnerClass {
        public void methodInInnerClass() {
            System.out.println("Method in Inner Class");
        }
    }
}

OuterClass outer = new OuterClass();
OuterClass.InnerClass inner = outer.new InnerClass();
inner.methodInInnerClass();