How do I join two lists in Java?

java list jdk1.5
Robert Atkins picture Robert Atkins · Oct 10, 2008 · Viewed 905k times · Source

Conditions: do not modifiy the original lists; JDK only, no external libraries. Bonus points for a one-liner or a JDK 1.3 version.

Is there a simpler way than:

List<String> newList = new ArrayList<String>();
newList.addAll(listOne);
newList.addAll(listTwo);

Answer

Dale Emery picture Dale Emery · Sep 8, 2013

In Java 8:

List<String> newList = Stream.concat(listOne.stream(), listTwo.stream())
                             .collect(Collectors.toList());

Related questions

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
Converting array to list in Java

How do I convert an array to a list in Java? I used the Arrays.asList() but the behavior (and signature) somehow changed from Java SE 1.4.2 (docs now in archive) to 8 and most snippets I found on the web use …

Read More