Java: Converting lists of one element type to a list of another type

java list element
user288140 picture user288140 · Mar 7, 2010 · Viewed 36.8k times · Source

I'm writing an adapter framework where I need to convert a list of objects from one class to another. I can iterate through the source list to do this as in

Java: Best way of converting List<Integer> to List<String>

However, I'm wondering if there is a way to do this on the fly when the target list is being iterated, so I don't have to iterate through the list twice.

Answer

Alexey Malev picture Alexey Malev · Aug 25, 2015

Java 8 way:

List<String> original = ...;
List<Wrapper> converted = original.stream().map(Wrapper::new).collect(Collectors.toList());

assuming Wrapper class has a constructor accepting a String.

Related questions

Check if one list contains element from the other

I have two lists with different objects in them. List<Object1> list1; List<Object2> list2; I want to check if element from list1 exists in list2, based on specific attribute (Object1 and Object2 have (among others), …

Read More
How to make a new List in Java

We create a Set as: Set myset = new HashSet() How do we create a List in Java?

Read More
How to initialize List<String> object in Java?

I can not initialize a List as in the following code: List<String> supplierNames = new List<String>(); supplierNames.add("sup1"); supplierNames.add("sup2"); supplierNames.add("sup3"); System.out.println(supplierNames.get(1)); I face the following error: …

Read More