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

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

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@stgerberding
T
ourguide
Software-Entwicklerin:

Java Web Anwendungen

Continuous Integration

Software-Architektur

T
witter:
 
@stgerberding

Blog:
 
http://sandra.gerberding.blog

E-Mail:
 
[email protected]

Speaker Deck:
 
https://speakerdeck.com/sandrag
Sandra Gerberding
2

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
3
JDK 15

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JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
4
JDK 15

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

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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

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@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

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@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

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@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())
;

})
;

}

}
9

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@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
10

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@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

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

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

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JDK10
Reserved T
ype „var“
Release
Docker Support
Collections
… und mehr …
14

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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");
15

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@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

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@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

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@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
18

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@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

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
20
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
21
JDK 15

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JDK11
 
L
TS
API Änderungen
JCMD / Flight Recorder
HTTP Client
Collections
… und mehr …
22

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@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 ())
;

;

final String string = " \u205Fnaked\u205F "
;

System.out.println ("strip String: '" + string.strip () + "'")
;

System.out.println ("trim String: '" + string.trim () + "'")
;

;

"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

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@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
24

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@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 neues API
25

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@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

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
27
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
28
JDK 15

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JDK12
Switch Expression
… und mehr …
Preview
29

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@stgerberding
- Kleine Änderungen

- Unicode 11

30

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
31
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
32
JDK 15

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@stgerberding
JDK13
Switch Expression
T
ext Blocks
… und mehr …
Preview
Preview
33

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@stgerberding
- FileSystems API hat 3 neue Methods

- newFileSystem(Path)

- newFileSystem(Path, Map)

- newFileSystem(Path, Map, ClassLoader)

- Unicode 12.1

- Und mehr …

34

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
35
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
36
JDK 15

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JDK14
Switch Expression
Records
… und mehr …
Preview
37

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@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
;

}
{

String quadrant
;

switch (species)
{

case KLINGONS
,

ROMULANS -> quadrant = "Beta quadrant"
;

case FERENGI
,

VULCANS
,

HUMANS -> quadrant = "Alpha quadrant"
;

default -> quadrant = "unknown quadrant"
;

}

return quadrant
;

}
{

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
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@stgerberding
JDK 14 - Switch Expressions
{

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

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@stgerberding
- Detaillierte NullPointerException Message mit JVM Option aktivierbar

- TLS Erweiterungen

- Und mehr …

40

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
41
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
42
JDK 15

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@stgerberding
JDK15
Records
Pattern Matching for instanceof
T
ext Blocks
… und mehr …
Preview
Preview
43

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@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

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@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

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@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

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@stgerberding
- 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 …

47

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
48
JDK 15

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@stgerberding
JDK 8 JDK 9
JDK 10
JDK 11
JDK 12
JDK 13
JDK 14
49
JDK 15

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@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

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@stgerberding
Vielen Dank

fürs Zuhören!
Zeichnungen: Sandra Gerberding
51

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@stgerberding
Bonus Folien
Zeichnungen: Sandra Gerberding
52

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@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());
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

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

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

Sandra Gerberding
PRO

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

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

Sandra Gerberding PRO

More Decks by Sandra Gerberding

Other Decks in Programming

Featured

Transcript

Sandra Gerberding
PRO