- Given an ArrayList collection containing String Objects in java.
- List<String> stringList = new ArrayList<String>();
- ArrayList collection will contain null elements also.
- [Soccer, Rugby, null, Badminton, null, Golf, null, Tennis]
- We would like to remove null elements/String objects from List of objects.
- We will use filter feature of lambda stream in Java8.
1. Filter/remove null elements from arraylist of objects – lambda stream
package org.learn.org.learn.files; import java.util.ArrayList; import java.util.List; import java.util.stream.Collectors; public class RemoveNullsFromList { public static void main(String[] args) { List<String> stringList = new ArrayList<>(); stringList.add( "Soccer" ); stringList.add( "Rugby" ); stringList.add( null ); stringList.add( "Badminton" ); stringList.add( null ); stringList.add( "Golf" ); stringList.add( null ); stringList.add( "Tennis" ); System.out.println( "1. Given ArrayList containing null string objects" ); System.out.println(stringList); System.out.println( "2. Removed null string objects from ArrayList collection" ); List<String> removedNulls = stringList .stream() .filter( value -> value != null ) .collect(Collectors.toList()); System.out.println(removedNulls); } } |
2. Output – remove null Strings from list of objects (lambda stream java 8)
1. Given ArrayList containing null string objects [Soccer, Rugby, null, Badminton, null, Golf, null, Tennis] 2. Removed null string objects from ArrayList collection [Soccer, Rugby, Badminton, Golf, Tennis] |