Java知多少（40）接口和抽象类的区别

 1 public abstract class A{
 2     public abstract void method1();
 3     public void method2(){
 4         //A method2
 5     }
 6 }
 7 public class B extends A{
 8     public void method1(){
 9         //B method1
10     }
11 }
12 public class C extends A{
13     public void method1(){
14         //C method1
15     }
16 }

 1 public interface A{
 2     public void method1();
 3     public void method2();
 4 }
 5 public class B implements A{
 6     public void method1(){
 7         //B method1
 8     }
 9     public void method2(){
10         //B method2
11     }
12 }
13 public class C implements A{
14     public void method1(){
15         //C method1
16     }
17     public void method2(){
18         //C method2
19     }
20 }

 1 interface A{
 2     public void method2();
 3 }
 4 interface B{
 5     public void method1();
 6 }
 7 class C implements A,B{
 8     public void method1(){
 9         //C method1
10     }
11     public void method2(){
12         //C method2
13     }
14 }
15 //可以如此灵活的使用C，并且C还有机会进行扩展，实现其他接口
16 A a=new C();
17 B b=new C();
18 abstract class A{
19     public abstract void method1();
20 }
21 abstract class B extends A{
22     public abstract void method2();
23 }
24 class C extends B{
25     public void method1(){
26         //C method1
27     }
28     public void method2() {
29         //C method2
30     }
31 }