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//: generics/CheckedList.java

package generics; /* Added by Eclipse.py */

// Using Collection.checkedList().

import typeinfo.pets.*;

import java.util.*;

public class CheckedList {

@SuppressWarnings("unchecked")

static void oldStyleMethod(List probablyDogs) {

probablyDogs.add(new Cat());

}

public static void main(String[] args) {

List<Dog> dogs1 = new ArrayList<Dog>();

oldStyleMethod(dogs1); // Quietly accepts a Cat

List<Dog> dogs2 = Collections.checkedList(

new ArrayList<Dog>(), Dog.class);

try {

oldStyleMethod(dogs2); // Throws an exception

} catch(Exception e) {

System.out.println(e);

}

// Derived types work fine:

List<Pet> pets = Collections.checkedList(

new ArrayList<Pet>(), Pet.class);

pets.add(new Dog());

pets.add(new Cat());

}

} /* Output:

java.lang.ClassCastException: Attempt to insert class typeinfo.pets.Cat element into collection with element type class typeinfo.pets.Dog

*///:~