內部類

public class TestInnerClass {
	/**It is a test of inner class.
	 * @param args
	 */
	public static void main(String[] args) {
		Animal a = new Animal();
		Animal.Dog b = a.new Dog();
		//在外圍類Animal的作用域之外的引用，outclass.innerclass classname = outclassName.new innerclass()
		b.look();
		a.output(200);
	}
}

class Animal {
	public class Dog {
		public void look() {
			System.out.println("The dog \"hong!hong!\"");
		}
	}
	
	public void output(final int x) {//局部內部類可以訪問局部變量，不過要聲明爲final，否則會出現編譯錯誤
		//局部內部類，沒有public之類的修飾符，只能在方法內部使用
		class Cat {
			public void out() {
				System.out.println("The cat \"miao!miao!\"" + x);
			}
		}
		
		Cat c = new Cat();
		c.out();
	}
}