After looking into the new features in Java 13, let’s continue with my series of Java new features with Java 14.

JEP 361: Switch Expressions

The changes around the Switch expressions from Java 12 and Java 13 are no longer preview! In summary, we can now do something like:

int numLetters = switch (day) {
    case MONDAY, FRIDAY, SUNDAY -> 6;
    case TUESDAY                -> 7;
    case THURSDAY, SATURDAY     -> 8;
    case WEDNESDAY              -> 9;
    default      -> {
        int result = foo(day); // some function
        yield result;
    }
};

JEP 368: Text Blocks (Second Preview)

To extend the text blocks capabilities from Java 13, text blocks now have two new escape sequences:

• \: to indicate the end of the line, so that a new line character is not introduced
• \s: to indicate a single space (can be used in traditional strings)

Example:

String text = """
{
    "name" : "Foo", \
    "surname" : "Buu" \s
}
""";

Additional methods:

• String::stripIndent(): used to strip away incidental white space from the text block content
• String::translateEscapes(): used to translate escape sequences
• String::formatted(Object… args): simplify value substitution in the text block

JEP 305: Pattern Matching for instanceof (Preview)

Another super enhancement in regards of user experience! The usage of the instanceof statement. Before, we had to do something like:

if (obj instanceof String) {
    String s = (String) obj;
    // use s
}

Now, we can simply do:

if (obj instanceof String s) {
    // can use s here
} else {
    // can't use s here
}

JEP 359: Records (Preview)

Are you bored of having to define the fields, getters and setters every time for a POJO class? Something like:

public class Person {
    private String name;
    private int age;

    public Person(String name, int age) { 
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

In Java 14, there is a new record statement that will ease the above by simply doing:

public record Person(String name, int age) { };

A really nice addition based on Kotlin!

JEP 358: Helpful NullPointerExceptions

Having this code in production:

a.b.c.i = 99;

When throwing a null pointer exception and we would see something like:

Exception in thread "main" java.lang.NullPointerException
    at Prog.main(Prog.java:5)

But… what is the field that is null? a or b or c? Now, the JVM will include more helpful information to help in these situations. The new message will look like as:

Exception in thread "main" java.lang.NullPointerException: 
        Cannot assign field "i" because "b" is null
    at Prog.main(Prog.java:5)

JEP 349: JFR Event Streaming

Previously, to get the JFR events, we had to dump the full content of the jfr file and read it. Now, we can read the events asynchronously, simply doing:

try (var rs = new RecordingStream()) {
  rs.enable("jdk.CPULoad").withPeriod(Duration.ofSeconds(1));
  rs.enable("jdk.JavaMonitorEnter").withThreshold(Duration.ofMillis(10));
  rs.onEvent("jdk.CPULoad", event -> {
    System.out.println(event.getFloat("machineTotal"));
  });
  rs.onEvent("jdk.JavaMonitorEnter", event -> {
    System.out.println(event.getClass("monitorClass"));
  });
  rs.start();
}

JEP 370: Foreign-Memory Access API (Incubator)

Introduce an API to allow Java programs to safely and efficiently access foreign memory outside of the Java heap.

This feature is really well described in Baeldung.

JEP 345: NUMA-Aware Memory Allocation for G1

Improve G1 performance on large machines by implementing NUMA-aware memory allocation.

ZGC garbage collector is now supported on Windows and macOS

The Z Garbage Collector, a scalable, low-latency garbage collector, was first introduced in Java 11 as an experimental feature. Initially, the only supported platform was Linux/x64, and now is supported on Windows and macOS.