一个有关向上转型的简单列子

package test;
import static test_1.PrintDome.*;

/*向上转型例子
 * 2016-8-29
 * Dugn
 * */
public class UpTrans {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  Cycle  cycle = new Cycle();
  Unicycle unicycle = new Unicycle();
  Bicycle  bicycle  = new Bicycle();
  Tircycle tircycle = new Tircycle();
  CreateCycle.printCycle(cycle);
  CreateCycle.printCycle(unicycle);
  CreateCycle.printCycle(bicycle);
  CreateCycle.printCycle(tircycle);
 }

}
class Cycle  {//创建基类
 public void raid(){
  print("Cycle-----");//区分方法
 }
}

class Unicycle extends Cycle {//子类1
 public void raid(){
  print("Unicycle-----");//子类区分方法
 }
}

class Bicycle  extends Cycle{
 public void raid(){
  print("Bicycle-----");
 }
}

class Tircycle  extends Cycle{
 public void raid(){
  print("Tircycle-----");
 }
}

class CreateCycle{
 
 public static void printCycle(Cycle cycle){
  cycle.raid();
 }
}

 

 

 

---------------------------

 

Cycle-----
Unicycle-----
Bicycle-----
Tircycle-----

 

个人理解向上转型就是基类同子类的范型应用，如Map 、LIst等