Java 11中的11个隐藏的宝石

List<EnterpriseGradeType<With, Generics>> types = /*...*/;
types.stream()
    // this is fine, but we need @Nonnull on the type
    .filter(type -> check(type))
    // in Java 10, we need to do this ~> ugh!
    .filter((@Nonnull EnterpriseGradeType<With, Generics> type) -> check(type))
    // in Java 11, we can do this ~> better
    .filter((@Nonnull var type) -> check(type))

2.

var multiline = "This\r\nis a\r\nmultiline\r\nstring";
multiline.lines()
    // we now have a `Stream<String>`
    .map(line -> "// " + line)
    .forEach(System.out::println);
 
// OUTPUT:
// This
// is a
// multiline
// string

3. 

Path tmp = Path.of("/home/nipa", "tmp");
Path codefx = Path.of(URI.create("http://codefx.org"));

String haiku = Files.readString(Path.of("haiku.txt"));
String modified = modify(haiku);
Files.writeString(Path.of("haiku-mod.txt"), modified);

InputStream input = InputStream.nullInputStream();
OutputStream output = OutputStream.nullOutputStream();
Reader reader = Reader.nullReader();
Writer writer = Writer.nullWriter();

String[] strings_fun = list.toArray(String[]::new);

public boolean needsToCompleteAddress(User user) {
    return getAddressRepository()
        .findAddressFor(user)
        .map(this::canonicalize)
        .filter(Address::isComplete)
        .isEmpty();
}

Stream.of("a", "b", "", "c")
    // statically import `Predicate.not`
    .filter(not(String::isBlank))
    .forEach(System.out::println);

Pattern nonWordCharacter = Pattern.compile("\\W");
Stream.of("Metallica", "Motörhead")
    .filter(nonWordCharacter.

())
    .forEach(System.out::println);