Java面向对象 匿名内部类

1. 匿名内部类其实就是内部类的简写格式

2，定义匿名内部类的前提：

     内部类必须是继承一个类或者实现接口

原始写法

package test;

abstract class AbsDemo {
	abstract void show();
}

class Outer {
	private int x = 1;
	public void setX(int x) {
		this.x = x;
	}
	public void function() {
		new Inner().show();
	}
	class Inner extends AbsDemo {
		void show() {
			if(x < 0 ) x = -x;
			System.out.println("abs(x) = " + x);
		}
	}
}

public class InnerClassDemo {
	public static void main(String[] args) {
		Outer a = new Outer();
		a.setX(-10);
		a.function();
		
	}
}
//abs(x) = 10

化简写法

package test;

abstract class AbsDemo {
	abstract void show();
}

class Outer {
	private int x = 1;
	public void setX(int x) {
		this.x = x;
	}
	public void function() {
		new AbsDemo() {
			void show() {
				if(x < 0 ) x = -x;
				System.out.println("abs(x) = " + x);
			}
		}.show();
	}
}

public class InnerClassDemo {
	public static void main(String[] args) {
		Outer a = new Outer();
		a.setX(-10);
		a.function();
		
	}
}
//abs(x) = 10