定義
- 使用interface定義
- 介面當中的方法都是抽象方法
- 介面當中的方法都是public權限
實作
- 實作介面使用implements關鍵字
- 一個類可以實作多個介面
- 一個介面可以繼承多個介面
一個類可以實作多個介面
public interface USB { void read(); void write(); }
public interface WiFi { void open(); void close(); }
public class Phone implements USB, WiFi { public Phone() { // TODO Auto-generated constructor stub System.out.println("Phone 無參構造"); } @Override public void open() { // TODO Auto-generated method stub System.out.println("open"); } @Override public void close() { // TODO Auto-generated method stub System.out.println("close"); } @Override public void read() { // TODO Auto-generated method stub System.out.println("read"); } @Override public void write() { // TODO Auto-generated method stub System.out.println("write"); } }
public class Test { public Test() { // TODO Auto-generated constructor stub } public static void main(String[] args) { // TODO Auto-generated method stub USB usb = new Phone(); usb.write(); usb.read(); WiFi wiFi = new Phone(); wiFi.open(); wiFi.close(); } }
運行結果
Phone 無參構造
write
read
Phone 無參構造
open
close一個介面可以繼承多個介面
public interface PhoneDevice extends USB, WiFi { void connect(); }
public class Phone implements PhoneDevice { public Phone() { // TODO Auto-generated constructor stub System.out.println("Phone 無參構造"); } @Override public void read() { // TODO Auto-generated method stub System.out.println("read"); } @Override public void write() { // TODO Auto-generated method stub System.out.println("write"); } @Override public void open() { // TODO Auto-generated method stub System.out.println("open"); } @Override public void close() { // TODO Auto-generated method stub System.out.println("close"); } @Override public void connect() { // TODO Auto-generated method stub System.out.println("connect"); } }
運行結果
Phone 無參構造
write
read
Phone 無參構造
open
close
Phone 無參構造
connect
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標籤：其他