Use case of collectionUtils

CollectionUtils.java

package com.knoldus;

import org.apache.commons.collections4.CollectionUtils;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class LambdaEx {

    public static void main(String[] args) {
        ArrayList<String> list = null;
        final List<String> modifiedCollection = CollectionUtils.emptyIfNull(list)
                .stream()
                .map(elem -> elem + " ")
                .collect(Collectors.toList());

        CollectionUtils.emptyIfNull(modifiedCollection).forEach(System.out::println);
    }
}