non-static variable this cannot be referenced from a static context

@H_404_5@

另一方面,当我把GenTest子类的代码放在“父”的类代码之外 – JavaApp1时,我没有得到这个错误.

public class JavaApp1 {

    class GenTest {  
        @Deprecated
        void oldFunction() {
            System.out.println("don't use that");
        }
        void newFunction() {
            System.out.println("That's ok.");
        }
    }

    public static void main(String[] args) {
        GenTest x = new GenTest();
        x.oldFunction();
        x.newFunction();
    }
}

为什么会这样？