Java11 New Features

You can find the video in the following two URLs:
https://youtu.be/zggphqAcUvw
https://youtu.be/ViL0flSGrGY

1. New Features
Haim Michael
June 4
th
, 2019
All logos, trade marks and brand names used in this presentation belong
to the respective owners.
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Java 11
1st Part https://youtu.be/zggphqAcUvw
2nd Part https://youtu.be/ViL0flSGrGY

2. © 1996-2018 All Rights Reserved.
Haim Michael Introduction
●Snowboarding. Learning. Coding. Teaching. More
than 20 years of Practical Experience.
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3. © 1996-2018 All Rights Reserved.
Haim Michael Introduction
●Professional Certifications
Zend Certified Engineer in PHP
Certified Java Professional
Certified Java EE Web Component Developer
OMG Certified UML Professional
●MBA (cum laude) from Tel-Aviv University
Information Systems Management
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4. © 2008 Haim Michael 20151026
Oracle JDK is not Free
As of Java 11, the Oracle JDK would no longer be free
for commercial use.
The Open JDK continues to be free. We can use it
instead. However, we won't get nor security updates
and nor any update at all.

5. © 2008 Haim Michael 20151026
Running Java File
We can avoid the compilation phase. We can compile
and execute in one command. We use the java
command. It will implicitly compile without saving the
.class file.

6. © 2008 Haim Michael 20151026
Running Java File

7. © 2008 Haim Michael 20151026
Java String Methods
The isBlank() method checks whether the string is
an empty string, meaning... whether the string solely
includes zero or more blanks. String with only white
characters is treated as a blank string.
public class Program {
public static void main(String args[]) {
var a = "";
var b = " ";
System.out.println(a.isBlank());
System.out.println(b.isBlank());
}
}

8. © 2008 Haim Michael 20151026
Java String Methods
The lines() method returns a reference for a stream
of strings that are substrings we received after splitting
by lines.
public class Program {
public static void main(String args[]) {
var a = "we\nlove\njava\nand\nkotlin";
var stream = a.lines();
stream.forEach(str->System.out.println(str));
}
}

9. © 2008 Haim Michael 20151026
Java String Methods
The strip(), stripLeading() and the
stripTrailing methods remove white spaces from
the beginning, the ending and the remr of the string. It
is a 'Unicode-Aware' evolution of trim();
public class Program {
public static void main(String args[]) {
var a = " we love kotlin ";
var b = a.strip();
System.out.println("###"+b+"###");
}
}

10. © 2008 Haim Michael 20151026
Java String Methods
The repeat() method repeats the string on which it is
invoked the number of times it receives.
public class Program {
public static void main(String args[]) {
var a = "love ";
var b = a.repeat(2);
System.out.println(b);
}
}

11. © 2008 Haim Michael 20151026
Using var in Lambda Expressions
As of Java 11 we can use the var keyword within
lambda expressions.
interface Calculation {
public int calc(int a,int b);
}
public class Program {
public static void main(String args[]) {
Calculation f = (var a, var b)-> a+b;
System.out.println(f.calc(4,5));
}
}

12. © 2008 Haim Michael 20151026
Using var in Lambda Expressions
When using var in a lambda expression we must use
it on all parameters and we cannot mix it with using
specific types.

13. © 2008 Haim Michael 20151026
Inner Classes Access Control
Code written in methods defined inside inner class can
access members of the outer class, even if these
members are private.
class Outer
{
private void a() {}
class Inner {
void b() {
a();
}
}
}

14. © 2008 Haim Michael 20151026
Inner Classes Access Control
As of Java 11, there are new methods in Class class
that assist us with getting information about the created
nest. These methods include the following:
getNestHost(), getNestMembers() and
isNestemateOf().

15. © 2008 Haim Michael 20151026
Epsilon
As of Java 11, the JVM has an experimental feature
that allows us to run the JVM without any actual
memory reclamation.
The goal is to provide a completely passive garbage
collector implementation with a bounded allocation limit
and the lowest latency overhead possible.
https://openjdk.java.net/jeps/318

16. © 2008 Haim Michael 20151026
Deprecated Modules Removal
As of Java 11, Java EE and CORBA modules that
were already marked as deprecated in Java 9 are now
completely removed.
java.xml.ws
java.xml.bind
java.activation
java.xml.ws.annotation
java.corba
java.transaction
java.se.ee
jdk.xml.ws
jdk.xml.bind

17. © 2008 Haim Michael 20151026
Flight Recorder
The Flight Recorder is a profiling tool with a negligible
overhead below 1%. This extra ordinary overhead
allows us to use it even in production.
The Flight Recorder, also known as JFR, used to be a
commercial add-on in Oracle JDK. It was recently open
sourced.

18. © 2008 Haim Michael 20151026
Flight Recorder
Using the jps command we can get the process id of
our Java program.

19. © 2008 Haim Michael 20151026
Flight Recorder
Using the jcmd command we can perform various
commands, such as jcmd 43659 JFR.start

20. © 2008 Haim Michael 20151026
Flight Recorder
Using the jcmd command together with JFR.dump we
can dump all data to a textual file we choose its name
and it location on our computer.

21. © 2008 Haim Michael 20151026
Flight Recorder
There are various possibilities to process the new
created data file.
https://github.com/lhotari/jfr-report-tool

22. © 2008 Haim Michael 20151026
The HTTP Client
As of Java 11, the HTTP Client API is more
standardized.
The new API supports both HTTP/1.1 and HTTP/2.
The new API also supports HTML5 WebSockets.

23. © 2008 Haim Michael 20151026
The HTTP Client
As of Java 11, the HTTP Client API is more
standardized. The new API supports both HTTP/1.1
and HTTP/2. The new API also supports HTML5
WebSockets.

24. © 2008 Haim Michael 20151026
The HTTP Client
package com.lifemichael.samples;
import java.io.IOException;
import java.net.http.*;
import java.net.*;
import java.net.http.HttpResponse.*;
public class HTTPClientDemo {
public static void main(String args[]) {
HttpClient httpClient = HttpClient.newBuilder().build();

25. © 2008 Haim Michael 20151026
The HTTP Client
HttpRequest request = HttpRequest.newBuilder() .uri(URI.create(
"http://www.abelski.com/courses/dom/lib_doc.xml"))
.GET()
.build();
try {
HttpResponse<String> response = httpClient.send(
request, BodyHandlers.ofString());
System.out.println(response.body());
System.out.println(response.statusCode());
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

26. © 2008 Haim Michael 20151026
The HTTP Client
The new HTTP Client allows us to initiate an
asynchronous HTTP request.
HttpClient
.sendAsync(request,BodyHandlers.ofString())
.thenAccept(response -> {
System.out.println(response.body());
//..
});

27. © 2008 Haim Michael 20151026
The HTTP Client
The new HTTP Client supports the WebSocket
protocol.
HttpClient httpClient = HttpClient.newBuilder()
.executor(executor).build();
Builder webSocketBuilder = httpClient.newWebSocketBuilder();
WebSocket webSocket = webSocketBuilder
.buildAsync(
URI.create("wss://echo.websocket.org"), … ).join();

28. © 2008 Haim Michael 20151026
Nashorn is Deprecated
As of Java 11, the Nashorn JavaScript engine and
APIs are deprecated. Most likely, in future versions of
the JDK.

29. © 2008 Haim Michael 20151026
The ZGC Scalable Low Latency GC
As of Java 11, we can use the ZGC. This new GC is
available as an experimental feature.
ZGC is a scalable low latency garbage collector. It
performs the expensive work concurrently without
stopping the execution of application threads for more
than 10ms.

30. © 2008 Haim Michael 20151026
The ZGC Scalable Low Latency GC
ZGC is suitable especially for applications that require
low latency and/or use a very large heap (multi-
terabytes).

31. © 2008 Haim Michael 20151026
Files Reading and Writing
Java 11 introduces two new methods that significantly
assist with reading and writing strings from and to files.
readString()
writeString()

32. © 2008 Haim Michael 20151026
Files Reading and Writing
public class FilesReadingDemo {
public static void main(String args[]) {
try {
Path path = FileSystems.getDefault()
.getPath(".", "welove.txt");
String str = Files.readString(path);
System.out.println(str);
} catch (IOException e) {
e.printStackTrace();
}
}

33. © 2008 Haim Michael 20151026
Files Reading and Writing
public class FilesWritingDemo {
public static void main(String args[]) {
Path path = FileSystems.getDefault()
.getPath(".", "welove.txt");
try {
Files.writeString(path,
"we love php", StandardOpenOption.APPEND);
} catch (IOException e) {
e.printStackTrace();
}
}
}

34. © 2008 Haim Michael 20151026
Q&A
Thanks for attending our meetup! I hope you enjoyed! I
will be more than happy to get feedback.
Haim Michael
[email protected]
0546655837