java implement class with generics code example
Example 1: java define a generic class that produces
List list = new ArrayList();
list.add("abc");
list.add(new Integer(5)); //OK
for(Object obj : list){
//type casting leading to ClassCastException at runtime
String str=(String) obj;
}
Example 2: java define a generic class that produces
List<String> list1 = new ArrayList<String>(); // java 7 ? List<String> list1 = new ArrayList<>();
list1.add("abc");
//list1.add(new Integer(5)); //compiler error
for(String str : list1){
//no type casting needed, avoids ClassCastException
}