@stgerberding Eine Reise durch die JDKs Sandra Gerberding – smartsteuer GmbH

@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

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 3

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 4

@stgerberding JDK9 JShell Jigsaw Private methods in interfaces Immutable Collections … und mehr … 5

@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

@stgerberding JDK 9 - Jigsaw package de.gerberding.tax.calculation.api ; import de.gerberding.tax.calculation.implementation.SimpleTaxCalculator ; public interface TaxCalculator { double computeVAT (double netPrice, double vatRate) ; double computeGrossPrice (double netPrice, double vatRate) ; static TaxCalculator createSimpleTaxCalculator () { return new SimpleTaxCalculator () ; } } package de.gerberding.tax.calculation.implementation ; import de.gerberding.tax.calculation.api.TaxCalculator ; public class SimpleTaxCalculator implements TaxCalculator { @Overrid e public double computeVAT (final double netPrice, final double vatRate) { return (netPrice / 100) * vatRate ; } @Overrid e public double computeGrossPrice (final double netPrice, final double vatRate) { return netPrice + computeVAT (netPrice, vatRate) ; } } module tax.calculation { exports de.gerberding.tax.calculation.api ; } 7

@stgerberding JDK 9 - Jigsaw public class TaxCalculatorClient { public static void main (final String[] args) { final TaxCalculator taxCalculator = new SimpleTaxCalculator () ; final double vat = taxCalculator.computeVAT (15.95, 19.00) ; final double grossPrice = taxCalculator.computeGrossPrice (20.45, 7) ; System.out.println ("---------- Tax Calculator ——————") ; System.out.println ("netPrice = 15.95 and vatRate = 19 => vat = " + vat) ; System.out.println ("netPrice = 20.45 and vatRate = 7 => grossPrice = " + grossPrice) ; } } module tax.client { requires tax.calculation ; } public class TaxCalculatorClient { public static void main (final String[] args) { final TaxCalculator taxCalculator = TaxCalculator.createSimpleTaxCalculator () ; final double vat = taxCalculator.computeVAT (15.95, 19.00) ; final double grossPrice = taxCalculator.computeGrossPrice (20.45, 7) ; System.out.println ("---------- Tax Calculator ------------") ; System.out.println ("netPrice = 15.95 and vatRate = 19 => vat = " + vat) ; System.out.println ("netPrice = 20.45 and vatRate = 7 => grossPrice = " + grossPrice) ; } } 8

@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 9

@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 10

@stgerberding JDK 9 - Private Methods in Interfaces public interface UserService { boolean isAllowed (User user, Right right) ; default List getRights (final User user) { final List 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 getRights (final User user) { final List userRights = new ArrayList<>() ; addAllUserRights (user, userRights) ; return userRights ; } private void addAllUserRights (final User user, final List userRights) { user.getRoles ().forEach ((Role role) -> { userRights.addAll(role.getRights()) ; }) ; } } 11

@stgerberding JDK 9 - Immutable Collections final List immutableLanguages = List.of ("Groovy", "Kotlin", "Java"); final List languagesShort = Collections.unmodifiableLis t (Arrays.asList ("Groovy", "Kotlin", "Java")); final List languages = new ArrayList<>() ; languages.add ("Groovy") ; languages.add ("Kotlin") ; languages.add ("Java") ; final List unmodifiableLanguages = Collections.unmodifiableList (languages); final Map 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 unmodifiableVessels = Collections.unmodifiableMap (starTrekVessels); final Map 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 12

@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 13

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 14

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 15

@stgerberding JDK10 Reserved T ype „var“ Release Docker Support Collections … und mehr … 16

@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 != List List 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"); 17

@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. 18

@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 19

@stgerberding JDK 10 - Collections final List names = getNames () ; final List immutableCopyOfNames = List.copyOf (names) ; System.out.println ("immutableCopyOfList type: " + immutableCopyOfNames.getClass ()) ; final Set colors = getColors () ; final Set immutableCopyOfColors = Set.copyOf (colors) ; System.out.println ("immutableCopyOfSet type: " + immutableCopyOfColors.getClass ()) ; final Map personAgeMapping = getPersonsAge () ; final Map immutableCopyOfMap = Map.copyOf (personAgeMapping) ; System.out.println ("immutableCopyOfMap type: " + immutableCopyOfMap.getClass ()) ; final List 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 20

@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 21

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 22

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 23

@stgerberding JDK11 
 L TS API Änderungen JCMD / Flight Recorder HTTP Client Collections … und mehr … 24

@stgerberding JDK 11 - JCMD/Flight Recorder sandragerberding@MacBook-Pro demo % jcmd 18743 VM.flag s 18743 : -XX:-BytecodeVerificationLocal -XX:-BytecodeVerificationRemote -XX:CICompilerCount=12 -XX:ConcGCThreads=3 -XX:G1ConcRefinementThreads=13 -XX:G1HeapRegionSize=4194304 -XX:GCDrainStackTargetSize=64 -XX:InitialHeapSize=1073741824 -XX:+ManagementServer -XX:MarkStackSize=4194304 -XX:MaxHeapSize=17179869184 -XX:MaxNewSize=10305404928 -XX:MinHeapDeltaBytes=4194304 -XX:NonNMethodCodeHeapSize=12163472 -XX:NonProfiledCodeHeapSize=239494768 -XX:ProfiledCodeHeapSize=0 -XX:ReservedCodeCacheSize=251658240 -XX:+SegmentedCodeCache -XX:TieredStopAtLevel=1 -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseG1GC 25

@stgerberding JDK 11 - JCMD/Flight Recorder 26

@stgerberding JDK 11 - JCMD/Flight Recorder 27

@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 28

@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> 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 29

@stgerberding final URI uri = new URI ("https://swapi.dev/api/planets/1/") ; final HttpRequest request = HttpRequest.newBuilder (uri).GET ().build () ; final HttpResponse.BodyHandler bodyHandler = HttpResponse.BodyHandlers.ofString () ; final HttpClient httpClient = HttpClient.newBuilder ().build () ; final HttpResponse 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 30

@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 31

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 32

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 33

@stgerberding JDK12 Switch Expression … und mehr … Preview 34

@stgerberding JDK 12 … und mehr … - Kleine Änderungen - Unicode 11 https://www.oracle.com/java/technologies/javase/12-relnote-issues.html 35

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 36

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 37

@stgerberding JDK13 Switch Expression T ext Blocks … und mehr … Preview Preview 38

@stgerberding JDK 13 … und mehr … - FileSystems API hat 3 neue Methods - newFileSystem(Path) - newFileSystem(Path, Map) - newFileSystem(Path, Map, ClassLoader) - Unicode 12.1 - Und mehr … https://www.oracle.com/java/technologies/javase/13-relnote-issues.html 39

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 40

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 41

@stgerberding JDK14 Switch Expression Records … und mehr … Preview 42

@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 43

@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 44

@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 45

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 46

@stgerberding JDK 8 JDK 9 JDK 10 JDK 11 JDK 12 JDK 13 JDK 14 47

@stgerberding JDK15 Records Pattern Matching for instanceof T ext Blocks … und mehr … Preview Preview 48

@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 49

@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 50

@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 51

@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 52

@stgerberding JDK 15 … und mehr … - CharSequence Erweiterung - Default Method CharSequence.isEmpty () - Hidden Classes - Unicode 13.0 - Nashorn Engine ist nicht mehr Bestandteil es JDKs - TLS Erweiterungen - Und mehr … https://www.oracle.com/java/technologies/javase/15-relnote-issues.html 53

@stgerberding Ausblick JDK 16 - Migrate from Mercurial to git - Migrate to GitHub - Pattern Matching of instanceof - Records - Sealed Classes (Second Preview) - Und mehr … http://openjdk.java.net/projects/jdk/16/ 54

@stgerberding Vielen Dank fürs Zuhören! Zeichnungen: Sandra Gerberding 55

@stgerberding Bonus Folien Zeichnungen: Sandra Gerberding 56

@stgerberding HttpResponse response = HttpClient.newBuilder( ) .authenticator(new Authenticator () { @Overrid e protected PasswordAuthentication getPasswordAuthentication() { return new PasswordAuthentication ( "username" , "password".toCharArray()) ; } }).build( ) .send(request, HttpResponse.BodyHandlers.ofString ()); CompletableFuture> 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 57