Java Next!

A Peek Under The Hood

#(int x, int y)(x * y)
Callable<String> c = () -> "done";
module jpms {
	requires more.work;
	exports migration.challenges;
}
module java.sql {
	requires transitive java.logging
	requires transitive java.xml
	uses java.sql.Driver
	exports java.sql
	exports javax.sql
	exports javax.transaction.xa
}
module java.sql {
	requires transitive java.logging
	requires transitive java.xml
}
module java.sql {
	exports java.sql
	exports javax.sql
	exports javax.transaction.xa
}
module java.sql {
	uses java.sql.Driver
}

module mysql.driver {
	provides java.sql.Driver
		with com.mysql.MySQLDriver;
}

List<Driver> drivers = new ArrayList<>();
ServiceLoader
	.load(Driver.class)
	.forEach(drivers::add);
# create image
$ jlink
	--output awesome-app
	--module-path $JAVA_HOME/jmods:mods
	--add-modules com.awesome.app
	--launcher awesome=com.awesome.app
# [ship image]
# use image
awesome-app/bin/awesome
var users = new ArrayList<User>();
URL codefx = new URL("http://codefx.org");
URLConnection connection = codefx.openConnection();
Reader reader = new BufferedReader(
	new InputStreamReader(
		connection.getInputStream()));
No no = new No();
AmountIncrease<BigDecimal> more =
	new BigDecimalAmountIncrease();
HorizontalConnection<LinePosition, LinePosition>
	jumping =
		new HorizontalLinePositionConnection();
Variable variable = new Constant(5);
List<String> names = List.of("Max", "Maria");
var codefx = new URL("http://codefx.org");
var connection = codefx.openConnection();
var reader = new BufferedReader(
	new InputStreamReader(
		connection.getInputStream()));
var no = new No();
var more = new BigDecimalAmountIncrease();
var jumping = new HorizontalLinePositionConnection();
var variable = new Constant(5);
var names = List.of("Max", "Maria");
rhetoricalQuestion.answer(yes -> "see my point?");
java HelloWorld.java
java HelloJava11.java
java --source 11 hello-java-11
#!/opt/jdk-11/bin/java --source 11
# from current directory:
./hello-java-11
# from PATH:
hello-java-11
DayOfWeek day = // ...
int numLetters = switch (day) {
	case MONDAY, FRIDAY, SUNDAY -> 6;
	case TUESDAY -> 7;
	case THURSDAY, SATURDAY -> 8;
	case WEDNESDAY -> 9;
};
int numLetters = switch (day) {
	case MONDAY, FRIDAY, SUNDAY -> 6;
	case TUESDAY -> 7;
	case THURSDAY, SATURDAY -> 8;
	case WEDNESDAY -> 9;
};
if (condition)
    result = doThis();
else
    result = doThat();
result = condition
	? doThis()
	: doThat();
int numLetters = switch (day) {
	case MONDAY, FRIDAY, SUNDAY: break 6;
	case TUESDAY: break 7;
	case THURSDAY, SATURDAY: break 8;
	case WEDNESDAY: break 9;
};
String html = """
	<html>
		<body>
			<p>"Hello, text blocks!"</p>
		</body>
	</html>
	"""
String html = """
	<html>
		<body>
			<p>"Hello, text blocks!"</p>
		</body>
	</html>
	"""
expected_damage = chance * damage
Object value = // ...
String formatted = switch (value) {
	case Integer i -> String.format("int %d", i);
	case Byte b    -> String.format("byte %d", b);
	case Long l    -> String.format("long %d", l);
	case Double d  -> String.format("double %f", d);
	case String s  -> String.format("String %s", s);
	default        -> "unknown " + value.toString();
};
public int eval(Node n) {
	return switch(n) {
		case IntNode(int i) -> i;
		case NegNode(Node n) -> -eval(n);
		case AddNode(Node left, Node right) ->
			eval(left) + eval(right);
	};
}
public record Range(int low, int high) {

	// compiler generates:
	//  * constructor, deconstructor
	//  * equals/hashCode/toString
	//  * accessors low(), high()

}
public record Range(int low, int high) {

	// compiler knows signature and assigns to fields
	public Range {
		if (low > high)
			throw new IllegalArgumentException();
	}

	public void setLow(int low) {
		if (low > this.high)
			throw new IllegalArgumentException();
		this.low = low;
	}

}
class ListWrapper<E> implements List<E> {

    private List<E> list;

    public int size() -> list.size();
    public T get(int index) -> list.get(index);
	public int indexOf(E el) = list::indexOf;

}
String regex = \"\+(\d*[.])?\d"
String yaml = \"""
	name: "Positive number"
	regex: "\+(\d*[.])?\d"
	""";
public value Range {

	// implicitly final
	private int low;
	private int high;

	// you write:
	//  * constructor, static factories
	//  * equals/hashCode/toString
	//  * accessors, etc.

}
public value Range {
	private int low;
	private int high;
}
List<int> ids = new ArrayList<>();

Java Next!

New Releases, Amber, Valhalla, and More Goodies

Lots to talk about!

Versions and features

Java 8

The core of Java 8

Project Lambda

Project Lambda

Projects…​

Java 9

The core of Java 9

Java Module System

Delaying Java since 2008!

JAR Hell is bad, mkay?

Modules

Module Declaration

Reliable Configuration

Strong Encapsulation

Feature Glance

Services

Loading Services

JLink

Application Image

More JLink Features

More JPMS Features

More About JPMS

Even More About JPMS

Project Jigsaw

Project Jigsaw

Java 9 history

Java 9 history

Projects…​

Java 10

The core of Java 10

Local-Variable Type Inference

Less typing, but still strongly typed

Type Duplication

Type Duplication

Type Deduplication

Rules of var

Rules of var

What About Readability?

Aligned Variable Names

What About Readability?

More on var

Even more on var

Project Amber

Java 11

The core of Java 11

Scripting Java

Faster feedback with fewer tools

Launching A Single Source File

Background

Use Cases

Scripts

Arbitrary File Names

Shebang Support

Isn’t that awesome?

Java 11

Java 12

The core of 12

Preview Feature

Switch Expression

Expression vs Statement

Expression vs Statement

Expression vs Statement

Arrow vs Colon

Arrow vs Colon

Switch Evolution

More about switch

Project Amber

Java 13

The core of 13

Text Block Sneak

Project Amber

The new world

The new world

What’s OpenJDK?

OpenJDK vs Oracle JDK

OpenJDK vs Oracle JDK

Projects…

Projects…

Rules of `var`

Rules of `var`

More on `var`

Even more on `var`