Java – Android/Java ArrayList maps to ArrayList

I don’t know how to map an array from a storage type to another type.
Unfortunately I can’t use Java 8.

I have ArrayList<

T> I want to map it so I will have ArrayList<String>
How can I achieve it?

Hypothesis.
T obj has the method obj.toString().

I googled it. All I can find is how to convert ArrayList<String> to String[] or Map<K, V> to ArrayList<V>

Thanks for your help!

The

streaming solution that maps from a certain type T to String is as follows:

ArrayList<String> resultSet =  
           someList.stream()
                   .map(Object::toString) // or ClassName::toString
                   .collect(Collectors.toCollection(ArrayList::new));

Equivalent to:

ArrayList<String> accumulator = new ArrayList<>();     
for(T obj : someList)
    accumulator.add(obj.toString());