Keynote

Original name

Keynote

Author(s)

Jiří Pinkas

Length

41:46

Date

12-11-2023

Language

Czech 🇨🇿

Rating

⭐⭐⭐☆☆

  • ✅ Compared to the previous year, the speaker less pushed what we must do.

  • ✅ More of time spent with upcoming Spring Boot and Java features.

  • ✅ Spring Modulith was mentioned.

  • ⛔ The data shown should be accompanied with the previous year data.

  • ⛔ I missed more detailed explanation on why popularity of some technologies suddenly dropped.

"Application servers seem are not dead yet."

Usage statistics

  • Java version: Java 8 (31%), Java 11 (28%), java 17 (19%), Java 18 and newer (6%), Kotlin (6%), Groovy (5%), Java 7 and older (3%), Scala (2%)

  • JRE/JDK distribution: Oracle Java (30%), Generic OpenJDK (21%), AdoptOpenJdk (15%), other (10%), Amazon Corretto (10%), Azul Zulu (5%), GraalVM (4%), IBM Semeru JDK (4%), OpenLogic JDK (2%)

    • 63% of companies plan to add additional Java developers, 28% are not sure and 9% said no.

  • Microservices:: Microservices (32%), Monolith (22%), Modular Monolith (12%), SOA (10%), Desktop App (7%), Mobile App (7%), Serverless (7%), other (3%)

  • Framework:

    • Spring Boot (59%), Other (24%), Quarkus (8%), Micronaut (6%), Vert.x (1%)

  • PaaS: AWS (22%), Microsoft Azure (15%), none (14%), IBM Cloud (13%), Red Hat Openshift (12%), Google Cloud Platform (8%), Oracle Cloud Platform (3%), other (3%), VMWare Tanzu (2%), Alibaba Cloud (2%), SAP Cloud Platform (2%), Pivotal Cloud Foundry (1%)

  • Application server: Tomcat (44%), WebSphere (13%), Jetty (10%), JBoss (9%), none (8%), WebLogic (6%), other (5%), WebLogic (7%), GlassFish (4%)

    • Application servers seem are not dead yet.

  • IDE: IntelliJ Idea (42%), Eclipse (27%), VSCode (22%), Netbeans (5%), other (3%), Browser-based IDE (1%)

  • Build tool: Most of the people use Maven but Spring Boot defaults to Gradle

Java 17-21 features

  • Virtual Threads (supported as of Spring Boot 3.2)

  • Language improvement

  • Performance improvement

  • JEP 431: Sequenced Collections

    Before:

    var last = list.get(list.size() - 1);

    After:

    var last = list.getLast();

  • Record Patterns and Pattern Matching + instanceof

    public void print(Object o) {
    if (o instanceofPosition(int x, int y)) {
        System.out.printf("o is a position: %d/%d%n", x, y);
    } else if (o instanceof String s) {
        System.out.printf("o is a string: %s%n", s);
    } else {
        System.out.printf("o is something else:  %s%n", o);
    }
}
    public void print(Object o) {
    switch (o) {
        case Position(int x, int y) -> System.out.printf("o is a position: %d/%d%n", x, y);
        case String s               -> System.out.printf("o is a string: %s%n", s);
        default                     -> System.out.printf("o is something else:  %s%n", o);
    }
}
    Object obj = getObject();

switch (obj) {
    case String s when s.length() > 5 -> System.out.println(s.toUpperCase());
    case String s                     -> System.out.println(s.toLowerCase());
    case Integer i                    -> System.out.println(i * i);
    case Position(int x, int y)       -> System.out.println(x + "/" + y);
    default                           -> {}
}

  • New String methods:

    • String.indexOf(String str, int beginIndex, int endIndex) - searches the specified substring in a subrange of the string.

    • String.indexOf(char ch, int beginIndex, int endIndex) - searches the specified character in a subrange of the string.

    • String.splitWithDelimiters (String regex, int limit) - splits the string at substrings matched by the regular expression and returns an array of all parts and splitting strings. The string is split at most limit-1 times, i.e., the last element of the array could be further divisible.

  • New StringBuilder/StringBuffer methods: Both StringBuilder and StringBuffer have been extended by the following two methods:

    • repeat (CharSequence cs, int count) - appends to the StringBuilder or StringBuffer the string cscount times.

    • repeat (int code Point, int count) - appends the specified Unicode code point to the StringBuilder or StringBuffer - count times. A variable or constant of type char can also be passed as code point.

  • New Math clamp function.

Spring Boot 3.1 features

Spring Boot 3.2 features