//: holding/ApplesAndOrangesWithoutGenerics.java

// Simple container example (produces compiler warnings).

// {ThrowsException}

package object;

import java.util.*;

class Apple {

  private static long counter;

  private final long id = counter++;

  public long id() { return id; }

}

class Orange {}    

public class ApplesAndOrangesWithoutGenerics {

  @SuppressWarnings("unchecked")

  public static void main(String[] args) {

    ArrayList apples = new ArrayList();

    for(int i = 0; i < 3; i++)

      apples.add(new Apple());

    // Not prevented from adding an Orange to apples:

    apples.add(new Orange());

    for(int i = 0; i < apples.size(); i++)

      ((Apple)apples.get(i)).id();//注释@SuppressWarnnigs("unchecked")抑制了类型转化错误信息

      // Orange is detected only at run time

  }

} /* (Execute to see output) *///:~