Hardware Interface
USB interface , UTP(网线接口)
Interface
一流的企业订协议
二流的企业做产品
a.More abstract than abstract class.
b.Data interaction
The defination of interface
We use 'interface' to define a interface
public interface dataInteraction{
}
Multiple inheritance(Different from class)
interface ti{
}
interface t2{
}
public interface dataInteraction extends t1,t2{
}
The inner elements in a interface
a.Can't instantiate (No constructors)
b.Only can define a static final variable.(But its default is this)
c.After we define a variable,we can access its member by "interface name + method name".
We use this way to replace the enumeration(枚举)
interface Season{
(public static final)int Spring = 1；
(public static final)int Summer = 2;
(public static final)int Autumn = 3;
(public static final)int Winter = 4;
}
public class MyClass{
main(){
Season.Spring;
}
}
The methods
In a interface,the default of a method is an abstract method.So if anyone invokes it and it should implement it.
public interface DataInteraction{
(public abstract)void input();
(public abstract)void output();
}
//Use implements to realize this interface
public class MacBook implements DataInteraction{
@Override
public void input(){
System.out.println("苹果电脑安全输入");
}
@Override
public void output(){
System.out.println("苹果电脑安全输出");
}
}
public class MyClass{
}
Inner interface
But the problem is,for some class,it may won't use the abstract method in the interface .Then we need to use the inner interface.
public interface DataInteraction{
interface Input{
(public abstract)void input();
}
interface Output{
(public abstract)void output();
}
}
public class Printer implements DataInteraction.Input{
//Nom this printer doesn't need to implement method Output
public void printf(){
System.out.println("打印机开始打印数据");
}
}
