The document discusses the history and appeal of Java, noting its adoption by BT for a university initiative and its ongoing popularity due to simplicity, extensive tools, and a large talent pool. It also addresses criticisms of Java, such as verbosity and framework limitations, while highlighting optimistic developments in recent versions, including functional programming features and modularity advancements. The selection of Java for projects is justified by the availability of talent, especially in the context of emerging Java features suitable for microservices architecture.

1. Why Java ?
Omar Bashir
https://www.linkedin.com/in/obprofile/ @OmarBashir_40

2. Background
Language From Used Last Used For
C 1995 2006 Dedicated/
Embedded Apps
Java 1996 Current Enterprise Apps
C++ 1998 2012 Dedicated/
Enterprise Apps
C# 2008 2015 Enterprise Apps
Scala 2012 2017 Enterprise Apps

3. Initial Adoption
● Mandated by BT for their University Research
Initiative (URI) in 1996 as a PoC.
● C-style but safer than both C and C++.
● Simpler than C++.
● WORA (Write Once Run Anywhere).

4. Continued Appeal
● Simple and intuitive concepts.
● Extensive tool support.
● A large and growing ecosystem.
● A wide talent pool globally.

5. Criticisms
● Verbosity
– Too much text leading to developer fatigue.
● Footprint
– Heavyweight class library.
● Elegance
– Largely imperative code.
● Syntactic sugar
– Generic erasures.

6. Criticisms
● Uniformity
– Primitives vs. wrapper classes.
– Autoboxing.
● Exceptions
– Checked and unchecked.
● Frameworkitis
– The disease that a framework wants to do too much
for you or it does it in a way that you don't want but
you can't change it.

7. Optimism - Elegance
● Functional programming since Java 8.
– Lambda expressions.
– Stream API.
● Collections factory methods since Java 9.
– Set<Integer> ints = Set.of(1, 2, 3);
● Additional Stream API methods in Java 9.
– dropWhile, takeWhile, iterate, ofNullable.
● Enhancements in String API all along.

8. Optimism - Verbosity
● Local variable type inferencing from Java 10.
– Optimises over diamond operator.
● var list = new ArrayList<String>();
● Switch statement improvements from Java 12.
– Converted to expressions returning values.
– Breaks removed.
– Multiple options serialised on a single line.
● Text blocks from Java 13.
– Complex multi-line text can be specified between
triple quotes (“””).

9. public void executeNewSwitchExpression(String day){
String result = switch (day) {
case "M", "W", "F" ­> "MWF";
case "T", "TH", "S" ­> "TTS";
default ­> {
if(day.isEmpty())
break "Please insert a valid day.";
else
break "Looks like a Sunday.";
}
};
System.out.println(result);
}
Switch Expression

10. Optimism - Modularity
● Project Jigsaw – Java 9
– Create a module system for the language.
– Apply it to the JDK source.
– Modularize the JDK libraries.
– Update the runtime to support modularity.
– Create smaller runtime with a subset of JDK modules.
● Stronger encapsulation at jar level.
– Better control of service granularity.

11. Selecting Java for a Project
● Technology unification programme initiated in
2015.
– Kotlin v1.0 released in early 2016 limiting choice
between Java and Scala.
● Talent – key reason for choosing Java.
– 90 developers in 4 global location.
● Microservices architecture.
– Choosing an appropriate language for the service.
– Emerging Java features made it a strong contender.

12. Reflections

13. A Tale of Reversion – Early 2016
● A Scala based microservices application.
● Challenges,
– Long cycle time to implement idiomatic Scala code.
– Steeper learning curve.
– Small, fluid talent pool.
● Piloted Java 8 with existing team,
– Positive overall developer experience.

14. THE END