Jul 21, 2022 By Team YoungWonks *
Java: Source code and Bytecode
Java, founded by James Gosling, appeared in May 1995. The first Java compiler was developed by Sun Microsystems. In case you are wondering what is a compiler, let’s understand how Java works.
- Java is developed to let the software engineers write platform independent code. This code, also known as source code, can be written on any machine (for example Linux, Windows or macOS).
- Since computers do not understand code written in English, Java provides a way to convert this code into machine understandable code called bytecode. This conversion is done by compiler that comes with the Java Development Kit (JDK).
- The important point to note here is that such compilers were available even before Java but they could not generate platform independent code. That means, apps or programs written in Java can run on any platform without the need to compile them again. This offers write once, run anywhere approach to the programmers.
- Running Java bytecode requires the machine to have Java Runtime Environment (JRE) that, behind the scenes, uses JVM (Java Virtual Machine) to run the bytecode.
- The programmer must have the Java Development Kit (JDK) on the system and the people who just need to run the bytecode must have Java Runtime Environment on the system. They can install the JDK if they want because it comes with JRE and development tools.
- That time, the Internet connectivity was very slow and in case you were supposed to fill a website form, the validation of this data required a round trip to the backend.
- If the validation failed, you had to fill the entire form again.
Every Java program must have its code organized in classes. Look at a very basic Java program:
In the above code, System.out.println(number); prints the data stored in the number variable.
Let’s observe the key differences in the syntax.
- Even though both the languages offer object-oriented programming (OOP), the Java programmer must write at least one class in the code.
For backend development (also known as server-side development), Java has a host of frameworks and this object-oriented programming language is widely used to develop enterprise level web applications. Some of the backend frameworks include
- It is a light weight scripting language
- It offers dynamic typing, object oriented programming support, client side validations and has many other features for web development
A set of instructions that can be scheduled for execution is called a thread. The process of running such threads simultaneously is known as multithreading.
- It keeps a queue of the tasks and executes them one by one
- When the external operation is done, the task is added again to the queue for further execution
- These two languages offer object-oriented programming approach for software development and web development
- Both of them make use of polymorphism to reuse code
For web development, you can read our following blogs:
- Introduction to Frontend Development https://www.youngwonks.com/blog/What-is-Back-End-Development
- HTML and CSS — Design and Build Websites https://www.youngwonks.com/blog/HTML-and-CSS-Design-and-build-websites
To get started with Java, you can read our following blog:
- Introduction to Java and Processing https://www.youngwonks.com/blog/Introduction-to-Java-and-Processing
*Contributors: Written by Rohit Budania; Lead image by Shivendra Singh