String multilineString = "Baeldung helps \n \n developers \n explore Java.";
List<String> lines = multilineString.lines()
.filter(line -> !line.isBlank())
.map(String::strip)
.collect(Collectors.toList());
assertThat(lines).containsExactly("Baeldung helps", "developers", "explore Java.");
List<String> sampleList = Arrays.asList("Java", "Kotlin");
String resultString = sampleList.stream()
.map((@Nonnull var x) -> x.toUpperCase())
.collect(Collectors.joining(", "));
assertThat(resultString).isEqualTo("JAVA, KOTLIN");
List sampleList = Arrays.asList("Java", "Kotlin");
String[] sampleArray = sampleList.toArray(String[]::new);
assertThat(sampleArray).containsExactly("Java", "Kotlin");
static <T> Predicate<T> not(Predicate<? spuer T> target) {
Objects.requireNonNull(target);
return (Predicate<T>)target.negate();
}
List<String> sampleList = Arrays.asList("Java", "\n \n", "Kotlin", " ");
List withoutBlanks = sampleList.stream()
.filter(Predicate.not(String::isBlank))
.collect(Collectors.toList());
assertThat(withoutBlanks).containsExactly("Java", "Kotlin");
New Features in Java 11 - Baeldung
JAVA 버전 별 특징(1~17버전) - 무사뎀벨레의 블로그