显示错误的Java代码：“内部类不能是公共的”？

public class OuterClass {
    private int outerVariable;

    public class InnerClass {
        public void innerMethod() {
            outerVariable = 10; // 访问外部类的成员变量
            System.out.println("This is an inner class");
        }
    }
}

public class OuterClass {
    private static int outerVariable;

    public static class InnerClass {
        public void innerMethod() {
            outerVariable = 10; // 访问外部类的静态成员
            System.out.println("This is a static inner class");
        }
    }
}

public class OuterClass {
    public void outerMethod() {
        final int localVar = 10; // 局部变量必须声明为final
        class LocalInnerClass {
            public void innerMethod() {
                System.out.println("This is a local inner class");
                System.out.println("Local variable: " + localVar);
            }
        }
        LocalInnerClass inner = new LocalInnerClass();
        inner.innerMethod();
    }
}

public class OuterClass {
    public void outerMethod() {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                System.out.println("This is an anonymous inner class");
            }
        };
        Thread thread = new Thread(runnable);
        thread.start();
    }
}