JDK11 features are frozen since it was in the Rampdown phase last month.
Big changes are listed in this page as JEPs.
JDK 11
However there are many changes outside of JPEs in JDK 11, therefore I list up the API changes in JDK 11 as far as I know.
String
lines()
Get a stream divided by line breaks.
jshell> "test\nhoge\n".lines().map(String::toUpperCase).toArray()
$11 ==> Object[2] { "TEST", "HOGE" }
repeat(int)
Repeat string for the specified times.
jshell> "test".repeat(3) $7 ==> "testtesttest"
isBlank()
The method appended that determines whether the string contains only spaces or not. Full width space is also treated as a space.
jshell> var halfSpace = "\u0020" halfSpace ==> " " jshell> halfSpace.isBlank() $11 ==> true jshell> var fullSpace = "\u3000" fullSpace ==> " " jshell> fullSpace.isBlank() $13 ==> true
strip() / stripLeading() / stripTrailing()
Almost same as trim() / trimLeft() / trimRight() but it takes full width spaces as a spece.
jshell> var aaa = fullSpace + "aaa" + fullSpace aaa ==> " aaa " jshell> aaa.strip() $14 ==> "aaa" jshell> aaa.trim() $15 ==> " aaa "
CharSequence
compare(CharSequence, CharSequence)
Sort by dictionaly order.
It is used by compateTo in CharSequence/StringBuffer/StringBuilder. Therefore the 3 classes implements Comparable.
Character
toString(int)
It was not convenient so far but now it become convenient.
JDK10.0.1
jshell> Character.toString(65) | Error: | incompatible types: possible lossy conversion from int to char | Character.toString(65) | ^^
JDK11ea14
jshell> Character.toString(65) $9 ==> "A"
Path
of(String, String...)
We had to use Paths.get() so far, now we can use of() as same manner as another classes.
Files
writeString(Path, CharSequence)
We can save a string with 1 method.
jshell> Files.writeString(Path.of("test.txt"), "Hello!!!")
$3 ==> test.txt
readString(Path)
We can read a string with 1 method.
jshell> Files.readString(Path.of("test.txt"))
$4 ==> "Hello!!!"
Reader
nullReader()
We can get a Reader that do nothing.
Writer
nullWriter()
We can get a Writer that do nothing.
Predicate
not(Predicate)
We could not use a method reference where it needs to invert the condition, now we can use a method reference.
jshell> Stream.of("aa", "", "bb").filter(Predicate.not(String::isEmpty)).toArray()
$23 ==> Object[2] { "aa", "bb" }
Collection
Optional/OptionalInt/OptionalLong/OptionalDouble
isEmpty()
isPresent() had existed so far, now we have isEmpty().
jshell> Optional.ofNullable(null).isEmpty() $5 ==> true
TimeUnit
convert(Duration)
added for java.util.concurrent.TimeUnit
Pattern
asMatchPredicate()
There was asPredicate that do find, now we have asMatchPredicate that do match.
jshell> var pred = Pattern.compile("aaa").asPredicate()
pred ==> java.util.regex.Pattern$$Lambda$25/0x00000008000b5040@2f686d1f
jshell> pred.test("aaa")
$6 ==> true
jshell> pred.test("aaab")
$7 ==> true
jshell> var matPred = Pattern.compile("aaa").asMatchPredicate()
matP ==> java.util.regex.Pattern$$Lambda$24/0x00000008000b6440@402a079c
jshell> matPred.test("aaa")
$9 ==> true
jshell> matPred.test("aaab")
$10 ==> false
ListSelectoinModel
getSelectedIndices()/getSelectedCount() are added.
Swing is changing!
Thread
destroy() / stop(Throwable)
Removed. stop() remains.
Policy
javax.security.auth.Policy is removed.
ArrayIndexOutOfBoundsException
The message become gentle for human.
JDK10.0.1
jshell> new int[]{}[0]
| java.lang.ArrayIndexOutOfBoundsException thrown: 0
| at (#8:1)
JDK11-ea14
jshell> new int[]{}[0]
| Exception java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0
| at (#4:1)
IndexOutOfBoundsException
hyphens are removed in the message.
JDK10.0.1
jshell> List.of().get(0) | java.lang.IndexOutOfBoundsException thrown: Index 0 out-of-bounds for length 0 | at Preconditions.outOfBounds (Preconditions.java:64) | at Preconditions.outOfBoundsCheckIndex (Preconditions.java:70) | at Preconditions.checkIndex (Preconditions.java:248) | at Objects.checkIndex (Objects.java:372) | at ImmutableCollections$List0.get (ImmutableCollections.java:106) | at (#6:1)
JDK11-ea14
jshell> List.of().get(0) | Exception java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 | at ImmutableCollections$ListN.get (ImmutableCollections.java:411) | at (#3:1)
System
arraycopy
The message become gentle for human.
JDK10
jshell> System.arraycopy(new int[0],0,new double[0],0,0) | java.lang.ArrayStoreException thrown
JDK11ea19
jshell> System.arraycopy(new int[0], 0, new double[0], 0, 0) | Exception java.lang.ArrayStoreException: arraycopy: type mismatch: can not copy int[] into double[]
setProperty(String, String)
So far changing java.home would make trouble but now it is not affect for the system, maybe...
Support Japanese new era.
It is introduced as NEWERA
Javaの新元号対応を試す。そして実用には問題がある - きしだのはてな
Boolean
parseBoolean
It become lettle faster to remove redundant null check, they said.
JDK10
public static boolean parseBoolean(String s) { return ((s != null) && s.equalsIgnoreCase("true")); }
JDK11
public static boolean parseBoolean(String s) { return "true".equalsIgnoreCase(s); }
I haven't confirmed it yet.
List
copyOf
copyOf that has introduced since Java10, it was wrong copying a subList. It could not be serialized. Now fixed.
Common initialize.
jshell> var list1 = List.of("a","b","c")
list1 ==> [a, b, c]
jshell> var list2=list1.subList(1,2)
list2 ==> [b]
jshell> var list3=List.copyOf(list2)
list3 ==> [b]
JDK11ea19
jshell> list2==list3 $13 ==> true jshell> new ObjectOutputStream(OutputStream.nullOutputStream()).writeObject(list3) | Exception java.io.NotSerializableException: java.util.ImmutableCollections$SubList | at ObjectOutputStream.writeObject0 (ObjectOutputStream.java:1185) | at ObjectOutputStream.writeObject (ObjectOutputStream.java:349) | at (#14:1)
JDK11ea20
jshell> list2==list3 $26 ==> false jshell> new ObjectOutputStream(OutputStream.nullOutputStream()).writeObject(list3) jshell>
TimSort
There are some bug, but fixed, maybe.
https://blog.satotaichi.info/timsort-was-broken/
