接口回调

package interfacecallback;
/**接口**/
public interface ShowMessage {
void showLabel(String s);
}


package interfacecallback;

public class PC implements ShowMessage{

public void showLabel(String s) {
// TODO Auto-generated method stub
System.out.println(s);
}

}
package interfacecallback;

public class TV implements ShowMessage{

public void showLabel(String s) {
// TODO Auto-generated method stub
System.out.println(s);
}

}

测试类：
package interfacecallback;

public class CallBackTest {
public static void main(String[] args) {
ShowMessage sm=null;
sm=new TV();
sm.showLabel("TV");//接口回调
sm=new PC();
sm.showLabel("PC");//接口回调
}
}