<dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>30.1-jre</version> </dependency> List<String> list = Lists.newArrayList("apple", "banana", "orange"); Set<Integer> set = ImmutableSet.of(1, 2, 3, 4); Map<String, Integer> map = ImmutableMap.of("key1", 1, "key2", 2); List<String> filteredList = list.stream() .filter(s -> s.startsWith("a")) .collect(Collectors.toList()); List<Integer> lengthList = list.stream() .map(String::length) .collect(Collectors.toList()); List<String> mergedList = Lists.newArrayList("apple", "banana"); mergedList.addAll(Lists.newArrayList("orange", "grapes")); List<String> sortedList = list.stream() .sorted() .collect(Collectors.toList());