Iterate over List> in Java

Question

I\'m trying to iterate List> in Java. However, I\'m not able to iterate it properly. Can any one guide me?

Itera         


        

Answer 1

You iterate over a list with elements of type Map. So casting to Map.Entry will give you a ClassCastException.

Try it like this

Iterator it = list.iterator();
while (it.hasNext()) {
    Map map = (Map) it.next();
    for (Map.Entry entry : map.entrySet()) {
        System.out.println(entry.getKey() + " = " + entry.getValue());
    }
}

It would be easier for you, if you didn't use the raw types Iterator and Map.Entry. Use generics wherever possible. So the code would look like this:

Iterator> it = list.iterator();
while (it.hasNext()) {
    Map map = it.next(); //so here you don't need a potentially unsafe cast
    for (Map.Entry entry : map.entrySet()) {
        System.out.println(entry.getKey() + " = " + entry.getValue());
    }
}