JavaLand2021: Eine-Reise-durch-die-JDKs-JavaLand

Folien vom Vortrag auf der JavaLand2021.

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1. @stgerberding Eine Reise durch die JDKs Sandra Gerberding – smartsteuer GmbH
2. @stgerberding T ourguide Software-Entwicklerin: Java Web Anwendungen Continuous Integration Software-Architektur T witter: 
 @stgerberding Blog: 
 http://sandra.gerberding.blog E-Mail: 
 sandra.gerberding@smartsteuer.de Speaker Deck: 
 https://speakerdeck.com/sandrag Sandra Gerberding 2
3. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 3 JDK 15
4. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 4 JDK 15
5. @stgerberding JDK9 JShell Jigsaw Private methods in interfaces Immutable Collections … und mehr … 5
6. @stgerberding JDK 9 - Jigsaw module tax.calculation { exports de.gerberding.tax.calculation.api ; } module tax.client { requires tax.calculation ; } module tax.calculation module tax.client package 
 …tax.calculation.implementation package 
 …tax.calculation.api package 
 …tax.client module-info.java module-info.java 6
7. @stgerberding JDK 9 - JShell jshell> Pattern.compile("(\\d{2})\\.(\\d{2})\\.(\\d{4})") ; $1 ==> (\d{2})\.(\d{2})\.(\d{4} ) | created scratch variable $1 : Patter n jshell> $1.matcher("02.09.2020") ; $2 ==> java.util.regex.Matcher[pattern=(\d{2})\.(\d{2})\.(\d{4}) region=0,10 lastmatch= ] | created scratch variable $2 : Matche r jshell> $2.matches( ) $3 ==> tru e | created scratch variable $3 : boolea n jshell> for (int group = 0; group <= $2.groupCount(); group++) { ...> System.out.println("group " + group + ": " + $2.group(group)) ; ...> } group 0: 02.09.202 0 group 1: 0 2 group 2: 0 9 group 3: 2020 7
8. @stgerberding JDK 9 - JShell jshell> /list -al l s1 : import java.io.* ; s2 : import java.math.* ; s3 : import java.net.* ; s4 : import java.nio.file.* ; s5 : import java.util.* ; s6 : import java.util.concurrent.* ; s7 : import java.util.function.* ; s8 : import java.util.prefs.* ; s9 : import java.util.regex.* ; s10 : import java.util.stream.* ; 1 : Pattern.compile("(\\d{2})\\.(\\d{2})\\.(\\d{4})") ; 2 : $1.matcher("02.09.2020") ; 3 : $2.matches( ) 4 : for (int group = 0; group <= $2.groupCount(); group++) { System.out.println("group " + group + ": " + $2.group(group)) ; } https://docs.oracle.com/javase/9/jshell/toc.htm 8
9. @stgerberding JDK 9 - Private Methods in Interfaces public interface UserService { boolean isAllowed (User user, Right right) ; default List<Right> getRights (final User user) { final List<Right> userRights = new ArrayList<>() ; user.getRoles ().forEach ((Role role) -> { userRights.addAll(role.getRights()) ; }) ; return userRights ; } } public interface UserService { boolean isAllowed (User user, Right right) ; default List<Right> getRights (final User user) { final List<Right> userRights = new ArrayList<>() ; addAllUserRights (user, userRights) ; return userRights ; } private void addAllUserRights (final User user, final List<Right> userRights) { user.getRoles ().forEach ((Role role) -> { userRights.addAll(role.getRights()) ; }) ; } } 9
10. @stgerberding JDK 9 - Immutable Collections final List<String> immutableLanguages = List.of ("Groovy", "Kotlin", "Java"); final List<String> languagesShort = Collections.unmodifiableLis t (Arrays.asList ("Groovy", "Kotlin", "Java")); final List<String> languages = new ArrayList<>() ; languages.add ("Groovy") ; languages.add ("Kotlin") ; languages.add ("Java") ; final List<String> unmodifiableLanguages = Collections.unmodifiableList (languages); final Map<Series, String> starTrekVessels = new HashMap<>() ; starTrekVessels.put (STAR_TREK, "NCC-1701") ; starTrekVessels.put (STAR_TREK_NG, "NCC-1701-D") ; starTrekVessels.put (STAR_TREK_VOYAGER, "NCC-74656") ; starTrekVessels.put (STAR_TREK_DS9, "NX-74205") ; final Map<Series, String> unmodifiableVessels = Collections.unmodifiableMap (starTrekVessels); final Map<Series, String> immutableVessels = Map.of (STAR_TREK, "NCC-1701" , STAR_TREK_NG, "NCC-1701-D" , STAR_TREK_VOYAGER, "NCC-74656" , STAR_TREK_DS9, "NX-74205"); JDK 8 JDK 9 JDK 8 JDK 9 List Map 10
11. @stgerberding JDK 9 … und mehr … - 2 neue Interfaces im Process API - java.jang.ProcessHandle - Java.jang.ProcessHandleInfo - Verbesserung von try with Resources - Completable Future API - Support delays and timeouts - Unicode 8 - String Optimierung (Speicherplatz) - JavaDoc erzeugt HTML 5 - Unterstützung von PKC512 in Keystores - Diamond Operator in anonymen Classes - Und mehr … https://docs.oracle.com/javase/9/whatsnew/toc.htm 11
12. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 12 JDK 15
13. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 13 JDK 15
14. @stgerberding JDK10 Reserved T ype „var“ Release Docker Support Collections … und mehr … 14
15. @stgerberding JDK 10 - Reserved T ype „var“ public class VarDemo { final var memberVariable = "Wej Qap!" ; public static void main (final String[] args) { var localVariable; // QoHbe' SuS ! String var; var personsVar = new ArrayList<>(); // ArrayList<Object> != List<Person> List<Person> persons = new ArrayList<>() ; var authorVar = getAuthor (); // Return value: Person? Author? …? Person author = getAuthor () ; } } var message = "Hello World!"; // String message = "Hello World!"; message = 1234; var person = new Person ("Gene", "Roddenberry"); 15
16. @stgerberding JDK 10 - Docker Support Host RAM Docker Container RAM JVM in Docker Container RAM 32 GByte 6 GByte 8 GByte Standard Wert 25% des Hosts Vor JDK 10 JVM in Docker Container RAM 1,5 GByte Standard Wert 25% des Docker Containers Ab JDK 10 Aus Designgründen sind die Größen nicht proportional dargestellt. 16
17. @stgerberding JDK 10 - Docker Support Host CPUs Docker Container CPUs JVM in Docker Container CPUs 6 CPUs 3 CPUs 6 CPUs Standard Wert 100% des Hosts Vor JDK 10 JVM in Docker Container CPUs 3 CPUs Standard Wert 100% des Docker Containers Ab JDK 10 17
18. @stgerberding JDK 10 - Collections final List<String> names = getNames () ; final List<String> immutableCopyOfNames = List.copyOf (names) ; System.out.println ("immutableCopyOfList type: " + immutableCopyOfNames.getClass ()) ; final Set<String> colors = getColors () ; final Set<String> immutableCopyOfColors = Set.copyOf (colors) ; System.out.println ("immutableCopyOfSet type: " + immutableCopyOfColors.getClass ()) ; final Map<String, Long> personAgeMapping = getPersonsAge () ; final Map<String, Long> immutableCopyOfMap = Map.copyOf (personAgeMapping) ; System.out.println ("immutableCopyOfMap type: " + immutableCopyOfMap.getClass ()) ; final List<String> immutableNames = names.stream ().collect (Collectors.toUnmodifiableList ()) ; System.out.println ("immutableNames type: " + immutableNames.getClass ()); immutableCopyOfList type: class java.util.ImmutableCollections$List N immutableCopyOfSet type: class java.util.ImmutableCollections$Set N immutableCopyOfMap type: class java.util.ImmutableCollections$Map N immutableNames type: class java.util.ImmutableCollections$ListN Console 18
19. @stgerberding JDK 10… und mehr … - Optional Erweiterung - Optional.orElseThrow () - JavaDoc Erweiterungen (css ..) - javah entfernt - Und mehr … https://www.oracle.com/java/technologies/javase/10-relnote-issues.html 19
20. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 20 JDK 15
21. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 21 JDK 15
22. @stgerberding JDK11 
 L TS API Änderungen JCMD / Flight Recorder HTTP Client Collections … und mehr … 22
23. @stgerberding JDK 11 - String - API Änderungen System.out.println ("Character: " + Character.toString (65)) ; System.out.println ("•".repeat (20)) ; final String blank = " " ; System.out.println ("'" + blank + "'.isBlank: " + blank.isBlank ()) ; System.out.println ("'" + blank + "'.isEmpty: " + blank.isEmpty ()) ; System.out.println ("•".repeat (20)) ; final String string = " \u205Fnaked\u205F " ; System.out.println ("strip String: '" + string.strip () + "'") ; System.out.println ("trim String: '" + string.trim () + "'") ; System.out.println ("•".repeat (20)) ; "a\nb\nc\nd\ne\nf".lines ().forEach (line -> System.out.println ("line = " + line)); Character: A ••••••••••••••••••• • ' '.isBlank: tru e ' '.isEmpty: fals e ••••••••••••••••••• • strip String: 'naked ' trim String: ' naked  ' ••••••••••••••••••• • line = a line = b line = c 23
24. @stgerberding JDK 11 - HTTP Client final URL url = new URL ("https://swapi.dev/api/planets/2/") ; final HttpURLConnection connection = (HttpURLConnection) url.openConnection () ; connection.setRequestMethod ("GET") ; connection.setRequestProperty ("Accept", "application/json") ; final int responseCode = connection.getResponseCode () ; final Map<String, List<String>> headers = connection.getHeaderFields () ; final BufferedReader in = new BufferedReader (new InputStreamReader (connection.getInputStream ())) ; String inputLine ; final StringBuilder responseBody = new StringBuilder () ; while ((inputLine = in.readLine ()) != null) { responseBody.append (inputLine) ; } in.close () ; connection.disconnect () ; System.out.println ("Status: " + responseCode) ; System.out.println ("Body: " + responseBody) ; System.out.println ("Headers: " + headers); JDK 8 altes API 24
25. @stgerberding final URI uri = new URI ("https://swapi.dev/api/planets/1/") ; final HttpRequest request = HttpRequest.newBuilder (uri).GET ().build () ; final HttpResponse.BodyHandler<String> bodyHandler = HttpResponse.BodyHandlers.ofString () ; final HttpClient httpClient = HttpClient.newBuilder ().build () ; final HttpResponse<String> response = httpClient.send (request, bodyHandler) ; final int responseCode = response.statusCode () ; final String responseBody = response.body () ; final HttpHeaders headers = response.headers () ; System.out.println ("Status: " + responseCode) ; System.out.println ("Body: " + responseBody) ; System.out.println ("Headers: " + headers.map ()); JDK 11 - HTTP Client JDK 11 neues API 25
26. @stgerberding JDK 11… und mehr … - T ransport Layer Security (TLS) 1.3 - „var“ Erweiterung - auch als Lambda Parameter - Unicode 10 - Applet, JavaFX … nicht mehr Bestandteil vom JDK 11 - Und mehr … https://www.oracle.com/java/technologies/javase/jdk-11-relnote.html 26
27. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 27 JDK 15
28. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 28 JDK 15
29. @stgerberding JDK12 Switch Expression … und mehr … Preview 29
30. @stgerberding JDK 12 … und mehr … - Kleine Änderungen - Unicode 11 https://www.oracle.com/java/technologies/javase/12-relnote-issues.html 30
31. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 31 JDK 15
32. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 32 JDK 15
33. @stgerberding JDK13 Switch Expression T ext Blocks … und mehr … Preview Preview 33
34. @stgerberding JDK 13 … und mehr … - FileSystems API hat 3 neue Methods - newFileSystem(Path) - newFileSystem(Path, Map<String, ?>) - newFileSystem(Path, Map<String, ?>, ClassLoader) - Unicode 12.1 - Und mehr … https://www.oracle.com/java/technologies/javase/13-relnote-issues.html 34
35. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 35 JDK 15
36. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 36 JDK 15
37. @stgerberding JDK14 Switch Expression Records … und mehr … Preview 37
38. @stgerberding JDK 14 - Switch Expressions public String findGalaxyQuadrant (final Species species) { String quadrant ; switch (species) { case KLINGONS : case ROMULANS : quadrant = "Beta quadrant" ; break ; case FERENGI : case VULCANS : case HUMANS : quadrant = "Alpha quadrant" ; break ; default : quadrant = "unknown quadrant" ; break ; } return quadrant ; } public String findGalaxyQuadrant (final Species species) { String quadrant ; switch (species) { case KLINGONS , ROMULANS -> quadrant = "Beta quadrant" ; case FERENGI , VULCANS , HUMANS -> quadrant = "Alpha quadrant" ; default -> quadrant = "unknown quadrant" ; } return quadrant ; } public String findGalaxyQuadrant (final Species species) { return switch (species) { case KLINGONS , ROMULANS -> "Beta quadrant" ; case FERENGI , VULCANS , HUMANS -> "Alpha quadrant" ; default -> "unknown quadrant" ; } ; } enum Species { KLINGONS, ROMULANS, FERENGI, VULCANS, HUMANS, BOR G } Classic Switch Statement New Switch Statement New Switch Expression 38
39. @stgerberding JDK 14 - Switch Expressions public String findGalaxyQuadrant (final Species species) { switch (species) { case KLINGONS , ROMULANS -> { return "Beta quadrant"; } case FERENGI , VULCANS , HUMANS -> { return "Alpha quadrant"; } default -> { return "unknown quadrant"; } } } public int computeNumberOfIndividuals (final Species species) { return switch (species) { case KLINGONS -> { final int individualsAlpha = calculateIndividualsPerQuadrant (KLINGONS, "Alpha") ; final int individualsBeta = calculateIndividualsPerQuadrant (KLINGONS, "Beta") ; yield individualsAlpha + individualsBeta ; } case HUMANS -> calculateIndividualsPerQuadrant (HUMANS, "Alpha") ; default -> 0 ; } ; } New Switch Statement with return New Switch Expression with yield 39
40. @stgerberding JDK 14 … und mehr … - Detaillierte NullPointerException Message mit JVM Option aktivierbar - TLS Erweiterungen - Und mehr … https://www.oracle.com/java/technologies/javase/14-relnote-issues.html 40
41. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 41 JDK 15
42. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 42 JDK 15
43. @stgerberding JDK15 Records Pattern Matching for instanceof T ext Blocks … und mehr … Preview Preview 43
44. @stgerberding JDK 15 - T ext Blocks final String exampleText = "Das ist ein\n" + " \"Beispiel\" Text!\n" + "Das ist ein etwas längerer Text und ich möchte ihn nur in der 'IDE' umbrechen. "; final String exampleText = "" " Das ist ei n "Beispiel" Text ! Das ist ein etwas längerer Text \ und ich möchte ihn nur in der 'IDE' umbrechen. \s"""; 'Das ist ei n "Beispiel" Text ! Das ist ein etwas längerer Text und ich möchte ihn nur in der 'IDE' umbrechen. ' Console 44
45. @stgerberding public record Cube (int height, int width, int depth) { } public final class Cube { private final int height ; private final int width ; private final int depth ; public Cube (int height, int width, int depth) { this.height = height ; this.width = width ; this.depth = depth ; } public int getHeight () { return height ; } public int getWidth () { return width ; } public int getDepth () { return depth ; } @Overrid e public boolean equals (Object o) { if (this == o) return true ; if (o == null || getClass () != o.getClass ()) { return false; } Cube cube = (Cube) o ; return height == cube.height & & width == cube.width & & depth == cube.depth ; } @Overrid e public int hashCode () { return Objects.hash (height, width, depth) ; } @Overrid e public String toString () { return "Cube {" + "height=" + height + ", width=" + width + ", depth=" + depth + '}' ; } } JDK 15 - Records Preview Syntax Struktur 45
46. @stgerberding public record Cube (int height, int width, int depth) implements Body { private final static int DENSITY = 3 ; public Cube () { this (1, 1, 1) ; } @Overrid e public int volume () { return height () * width () * depth () ; } } JDK 15 - Records Preview Syntax 46
47. @stgerberding JDK 15 … und mehr … - CharSequence Erweiterung - Default Method CharSequence.isEmpty () - Sealed Classes Preview - Hidden Classes - Unicode 13.0 - Nashorn Engine ist nicht mehr Bestandteil des JDKs - TLS Erweiterungen - Und mehr … https://www.oracle.com/java/technologies/javase/15-relnote-issues.html 47
48. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 48 JDK 15
49. @stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 49 JDK 15
50. @stgerberding Ausblick JDK 16 - Migrate from Mercurial to git - Migrate to GitHub - Pattern Matching for instanceof - Records - Sealed Classes (Second Preview) - Und mehr … http://openjdk.java.net/projects/jdk/16/ 50
51. @stgerberding Vielen Dank fürs Zuhören! Zeichnungen: Sandra Gerberding 51
52. @stgerberding Bonus Folien Zeichnungen: Sandra Gerberding 52
53. @stgerberding HttpResponse<String> response = HttpClient.newBuilder( ) .authenticator(new Authenticator () { @Overrid e protected PasswordAuthentication getPasswordAuthentication() { return new PasswordAuthentication ( "username" , "password".toCharArray()) ; } }).build( ) .send(request, HttpResponse.BodyHandlers.ofString ()); CompletableFuture<HttpResponse<String>> response3 = HttpClient.newBuilder( ) .build( ) .sendAsync(request, HttpResponse.BodyHandlers.ofString()); JDK 11 - HTTP Client Connection mit Authenticator HttpClient.newBuilder ().build ().sendAsync (request, HttpResponse.BodyHandlers.ofString () ) .thenApply (response -> { System.out.println (response.statusCode ()) ; return response ; } ) .thenApply (HttpResponse::body ) .thenAccept (System.out::println); Asynchronous Connection 53