genericsandupcasting.java

thinking in java 书中源码 第四版

//: holding/GenericsAndUpcasting.java
import java.util.*;

class GrannySmith extends Apple {}
class Gala extends Apple {}
class Fuji extends Apple {}
class Braeburn extends Apple {}

public class GenericsAndUpcasting {
  public static void main(String[] args) {
    ArrayList<Apple> apples = new ArrayList<Apple>();
    apples.add(new GrannySmith());
    apples.add(new Gala());
    apples.add(new Fuji());
    apples.add(new Braeburn());
    for(Apple c : apples)
      System.out.println(c);
  }
} /* Output: (Sample)
GrannySmith@7d772e
Gala@11b86e7
Fuji@35ce36
Braeburn@757aef
*///:~