Technology loves acronyms. GUI for graphical user interface. DLL for dynamic link library. FIFO for first in, first out.  So, what does WORA in Java mean?

Is it some secret code that only programmers understand? If not, then what does it mean and why is it important?

WORA stands for write once, run anywhere.

An alternative acronym is WORE, which stands for write once, run everywhere. Both acronyms refer to Java’s ability to run on any device regardless of the operating system or hardware components.

Why Call Java WORA?

Java is an object-oriented programming language. It is designed as a class-based language that relies on as few dependencies as possible so it can run on any platform.

Java is a compiled language that operates in the Java Virtual Machine (JVM). That makes Java portable code, meaning the same code can run on all computers regardless of the operating system or hardware.

Making Java work as a portable code requires more than just writing lines of code. It requires that Java source code be compiled and run in the Java Virtual Machine.

Java source code uses a compiler that creates a java program file (*.java) and converts it into class files that contain bytecodes. Bytecodes are platform-independent, but cannot execute unless they are operating in a JVM.

The process of converting source code to bytecodes to run in a JVM is what gives Java its WORA capability.

What Is Java Virtual Machine?

Java Virtual Machine (JVM) provides the runtime environment in which Java bytecode files are executed.  Operating as a virtual machine within the confines of the physical platform means that a JVM is not platform-independent.

If operating in a Windows environment, the JVM must be compatible with the appropriate release of Windows.  The same rule applies in an iOS or Unix/Linux environment.

Because the JVM is platform dependent, it is aware of the specific requirements of the physical platform, which means it cannot operate as a WORA application.

It depends on the operating system’s kernel, which varies from OS to OS. The JVM takes the bytecode and translates it into machine language and executes the machine-language instructions.

Java can only operate within a JVM environment. If it weren’t for JVM, Java would not be able to operate as a write once, run anywhere language.

What Is a Java Compiler?

Most programming languages compile before runtime or ahead of time (AOT). Java compilers convert source code into bytecodes before runtime.

Java also has the ability to compile at runtime or just-in-time (JIT). The JIT compiler is part of the Java Runtime Environment and is designed to improve the performance of Java applications.

Female programmer working on new project.

The standard Java operation uses the JVM to load the compiled Java bytecodes (*.class files) at runtime and convert them into machine code using an interpreter.

Alternatively, the JIT compiler can be enabled, which analyzes the method calls in the *.class files and compiles them into a more efficient machine code.

The JVM then loads the compiled code instead of interpreting it.  By executing the optimized code, the Java application should run faster.

As with most technology, compilers have improved. The JIT compiler, unlike other compilers, improves the performance of existing programs.

That means that code written years ago can run faster when compiled with the latest JIT compiler. However, the JIT compiler increases the unpredictability and complexity of a Java program, making it more difficult to troubleshoot.

JIT compilers also require more memory than the ahead-of-time compiled code. As a result, large Java applications use AOT compilers.

Java, an Internet Language

Java has become known as the programming language for internet applications.  Server-side applications are written in Java because of its general-purpose capabilities and its  web-based programming features such as:

  • Cross-Platform Support: Java’s architecture creates cross-platform capabilities.  Combining Java source code with Java’s runtime Environment and virtual machine enables Java programs to operate on any platform.
  • Internet Protocol Support: Java has a number of classes that support internet protocols such as HTTP, FTP, IP, TCP-IP and SMTP.  Integrated support for various protocols shortens the time to market for web applications.
  • HTML Support: Most web pages use HTML to create pages for user interaction.  Java provides HTML support, including the ability to parse and create HTML documents.  This support makes creating web applications much simpler.
  • API Support: Java has a class of APIs that retrieves values from specified fields and creates objects that result in methods for achieving desired functionality, saving coding time and increasing application flexibility.
  • XML Parsing Support: Java has specific APIs that read XML data and create XML documents, which allows data sharing across applications.
  • Web Services Support: Any web-based application relies on web services to function.  Java includes features that make it easier to implement these web services.

Programming support for multiple web-based features reduces the time it takes to create and deliver web applications. That’s why Java has become the programming language for internet applications.

Why Java?

Java may be associated with web development, but it is used in a variety of other environments such as:

  • Android apps. Java is the default language for Android apps, opening the door to the development of mobile applications.
  • Finance programs. The financial services industry uses Java for both its server- and client-side web applications. Use Java for the financial sector’s simulation and modeling.
  • Point of sale systems. Whether the point-of-sale system is a physical card acceptance terminal or an e-commerce solution, Java provides a portable code solution. Applications need to run on different hardware devices, so Java’s WORA capabilities are in demand.

Because Java provides access to tested libraries, debuggers, and monitoring tools, it remains one of the top programming languages.

Learning Java can be the first step in finding a career that has meaning and purpose. With its diverse applications, Java gives you the freedom to choose a career that is right for you. Discover the software development program powered by Woz U and begin your journey to a rewarding career.

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