[英]How do I print method of interface
如何打印接口的連接方法? 我只想通過最小化類修改來修改電源。
如果我使用arr [0] .connect(); 錯誤:未為設備類型定義方法connect()
public class main{
private static Device arr[];
public static void main(String[] args) {
// TODO Auto-generated method stub
init();
arr[0].print();
arr[1].print();
}
public static void init() {
arr = new Device[2];
arr[0] = new Printer();
arr[1] = new UsbMem();
}
}
public interface Connectable {
public static final String name = ":USB";
public abstract void connect();
}
public abstract class Device {
public abstract void print();
}
public class Printer extends Device implements Connectable {
public void print() {
System.out.println("It's a printer");
}
public void connect() {
System.out.println(name + "connect with printer");
}
}
public class UsbMem extends Device implements Connectable {
public void print() {
System.out.println("USB memory");
}
public void connect() {
System.out.println(name + "connect with usb memory");
}
}
這是打印機。 :USB與打印機USB存儲器連接:USB與USB存儲器連接
Device
需要實現Connectable
。
public class Main {
private static Device arr[];
public static void main(String[] args) {
// TODO Auto-generated method stub
init();
arr[0].print();
arr[1].print();
}
public static void init() {
arr = new Device[2];
arr[0] = new Printer();
arr[1] = new UsbMem();
}
}
public interface Connectable {
public static final String name = ":USB";
public abstract void connect();
}
public abstract class Device implements Connectable {
public abstract void print();
}
public class Printer extends Device {
public void print() {
System.out.println("It's a printer");
}
public void connect() {
System.out.println(name + "connect with printer");
}
}
public class UsbMem extends Device {
public void print() {
System.out.println("USB memory");
}
public void connect() {
System.out.println(name + "connect with usb memory");
}
}
將對象投射到可連接對象
((Connectable)arr[0]).connect()
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