Splitting a list in Java

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How to split a list into multiple parts of the same size seems like a common question (1,2). Most answers either point to adding an additional library such as Guava or Apache Commons.

As an experiment I’ve tried a differend approach. Splitting a list by using recursion.

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public static <T> List<List<T>> split(List<T> source, Integer partitionSize) {
       if(partitionSize < 1){
       	throw new IllegalArgumentException("partitionSize must be at least 1");
       }
	
	if(source.isEmpty()){
           return new ArrayList<>();
       }
       int currentChunkSize = Math.min(partitionSize, source.size());
       List<T> head = source.subList(0, currentChunkSize);
       List<T> tail = source.subList(currentChunkSize, source.size());
       List<List<T>> result = split(tail, partitionSize);
       result.add(0, head);
       return result;
   }

Testing the code seems to generate a successful output:

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@Test
 public void splitTest() {
        List<String> source = Arrays.asList("1", "2", "3", "4", "5");
       
        List<List<String>> result = split(source, 3);
        assertEquals(Arrays.asList("1", "2", "3"), result.get(0));
        assertEquals(Arrays.asList("4", "5"), result.get(1));
    }

However there is a word of warning! Java does not support Tail recursion optimization. So depending on your JVMs stacksize you may receive a StackOverflowError if you split a collection in more then 7000 parts.