Learning Java - History, Background & Why You Need Java

#Introduction

With your environment ready from episode 0, it is time to understand where Java comes from and why this language is so important. Episode 1 traces the history of Java — from a small project at Sun Microsystems to the language powering billions of devices and most of the world's enterprise systems.

Understanding the history is not mere nostalgia. The evolution of Java explains many technical decisions you will encounter throughout the series: why bytecode exists, why the LTS release model exists, and why the ecosystem is so large. With this context, every following concept feels more meaningful.

#The Beginnings of Java at Sun Microsystems

#The Green Project and the Write Once Run Anywhere Philosophy

Java was born from the Green Project, led by James Gosling at Sun Microsystems in the early 1990s. Initially designed for consumer electronic devices under the name Oak, the language was later renamed Java and publicly released in 1995.

Its big promise was Write Once, Run Anywhere (WORA): code compiled into bytecode can run on any platform as long as a JVM exists. This is what made Java revolutionary — applications no longer needed to be recompiled for every operating system.

#Why Java Was Needed Back Then

In the 1990s, applications had to be rewritten for every platform. The web was just starting to grow and needed interactive content. Java provided two answers: portability through the JVM and execution in the browser through Java Applets, making it the most popular language in the early days of the internet.

#Evolution of the Java Platform: from JDK 1.0 to JDK 21 LTS

#The Early Generations and Maturity

JDK 1.0 was released in 1996 with around 250 classes. JDK 1.2 in 1998 introduced the Collections Framework, Swing, and the J2SE, J2EE, and J2ME editions. Java 5 in 2004 added generics, annotations, and the enhanced for loop, which changed the way everyday code was written.

#The Modern Era and LTS

Java 8 in 2014 brought lambdas and the Stream API, which revolutionized programming style. Java 9 introduced JPMS (the module system) and jshell. Java 11 became the first LTS under Oracle's new release model. Java 17 brought sealed classes and pattern matching. JDK 21 in 2023 added virtual threads and record patterns as LTS features.

The following command shows the JDK version currently in use:

java -version
java --version

java -version shows detailed version information, while java --version shows a one-line summary. Both are useful for confirming which version is being used.

#The Modern Release Model: Six-Month Cadence and Two-Year LTS

#Six-Monthly Feature Releases

Since 2018, Java has adopted a time-based release model: a feature release every six months, in March and September. Version numbers increase sequentially — 21, 22, 23, and so on — without major-minor numbering.

#An LTS Every Two Years

Every two years, one release is designated as an LTS (Long-Term Support) release, supported for a longer period in production. JDK 21 is the current LTS, replacing JDK 17. For developers of production applications, choosing an LTS version is the safest decision because of the guarantee of security updates and stability.

Maret + September: rilis fitur setiap 6 bulan
Dua tahunan: versi LTS, misalnya 17 dan 21

#Problems Solved and Comparison with Traditional Approaches

#Portable Bytecode vs Native Compilation

The traditional approach compiles code into platform-specific machine instructions. Java solved portability with bytecode executed by the JVM. There is a trade-off: the JVM adds an abstraction layer, but compensates with a JIT compiler that makes execution fast.

#Automatic Memory Management vs Manual

Languages such as C and C++ require developers to allocate and free memory manually. Java uses automatic garbage collection: objects that are no longer referenced are cleaned up by the JVM itself. This eliminates a dangerous class of bugs such as memory leaks and dangling pointers.

#A Class Ecosystem for Enterprise and Cloud-Native

Java has the largest ecosystem for enterprise: Spring, Jakarta EE, Hibernate, and thousands of libraries on Maven Central. For web applications, mobile (Android), and microservices, Java is a top choice because of its stability and broad community support.

#Why Java Is Still Relevant for Modern Backend

#Cloud-Native and Performance

Java keeps adapting to the cloud era. Native images via GraalVM, virtual threads for high concurrency, and lightweight frameworks such as Quarkus keep Java competitive for cloud-native applications. Many financial, e-commerce, and large platform companies still run on Java.

#Stability and Long-Term Investment

Strong backward compatibility means code written ten years ago can still run on the latest JDK. For companies, this means a safe investment. The combination of performance, ecosystem, and stability is what has kept Java alive for more than two decades.

#Where Java Is Used Today

#Segments Dominated by Java

Java is present in almost every sector: enterprise applications, banking and financial services, e-commerce, transportation systems, and billions of Android devices. Consistently, Java ranks at the top of the most popular programming languages in the world.

perbankan & layanan keuangan
e-commerce & logistik
platform cloud & big data
aplikasi Android

#Java in the AI and Cloud Era

Java is also adapting to new trends: native images via GraalVM simplify lightweight deployment, virtual threads improve the efficiency of cloud services, and many data and AI platforms run on the JVM. The foundation you learn throughout this series is your capital for building in that era.

#Closing

Episode 1 explains why Java became one of the most important languages in the world: born at Sun Microsystems with the Write Once Run Anywhere philosophy, evolved from JDK 1.0 to JDK 21 LTS, using a six-month release model with two-year LTS releases, and solving problems of portability and memory management.

Key takeaways:

• Java was born from the Green Project at Sun Microsystems with the WORA philosophy.
• The evolution runs from JDK 1.0 to JDK 21 LTS, which is the current standard.
• Modern release model: six-monthly features and two-year LTS.
• Bytecode on the JVM solves portability; garbage collection handles memory.
• The huge ecosystem keeps Java relevant for enterprise and cloud-native.

In the next episode, episode 2, we will discuss core concepts and main architecture — the compilation process from source code to bytecode, the JVM architecture with the class loader, bytecode verifier, JIT compiler, and garbage collector, the roles of JDK, JRE, and JVM, the standard project structure, and classpath, module path, and JPMS. These are the technical foundations working behind every Java program.