Split a alphabetically sorted list into sublists based on alphabets in java

Question

I have a sorted list in java, i just want to split this list into sublists based on the first alphabet at each index of list. For example List contains

{
cal         


        

Answer 1

If you are open to using a third-party library, Eclipse Collections 7.x will work with Java 6. Using Eclipse Collections MutableList you can call groupBy as follows:

MutableList list = 
        Lists.mutable.with("calculator", "catch", "doll", "elephant");
Multimap multimap = 
        list.groupBy(StringFunctions.firstLetter());
System.out.println(multimap); 
// Prints {d=[doll], e=[elephant], c=[calculator, catch]}

If you need to use a java.util.List for the Strings, then you can use the ListAdapter class.

List list =
        Arrays.asList("calculator", "catch", "doll", "elephant");
Multimap multimap =
        ListAdapter.adapt(list).groupBy(StringFunctions.firstLetter());

Note: I am a committer for Eclipse Collections.