In this tutorial, we will cover everything from the basics of Java syntax to advanced topics like object-oriented programming and exception handling. So, by the end of this tutorial, you will have a strong understanding of Java and be ready to start writing your own Java applications. Java the among the top names along with Silk, and since java was a unique name so most of them preferred it.
Java is the name of an island in Indonesia where the first coffee(named java coffee) was produced. And this name was chosen by James Gosling while having coffee near his office. Note that Java is just a name, not an acronym.
Java Terminology
Before learning Java, one must be familiar with these common terms of Java.
Java Virtual Machine(JVM): This is generally referred to as JVM. There are three execution phases of a program. They are written, compile and run the program.
Writing a program is done by a java programmer like you and me.
The compilation is done by the JAVAC compiler which is a primary Java compiler included in the Java development kit (JDK). It takes the Java program as input and generates bytecode as output.
In the Running phase of a program, JVM executes the bytecode generated by the compiler.
Now, we understood that the function of Java Virtual Machine is to execute the bytecode produced by the compiler. Every Operating System has a different JVM but the output they produce after the execution of bytecode is the same across all the operating systems. This is why Java is known as a platform-independent language.
Bytecode in the Development Process: As discussed, the Java c compiler of JDK compiles the java source code into bytecode so that it can be executed by JVM. It is saved as .class file by the compiler. To view the bytecode, a disassembler like java p can be used.
Java Development Kit(JDK): While we were using the term JDK when we learn about bytecode and JVM. So, as the name suggests, it is a complete Java development kit that includes everything including compiler, Java Runtime Environment (JRE), java debuggers, java docs, etc. For the program to execute in java, we need to install JDK on our computer in order to create, compile and run the java program.
Java Runtime Environment (JRE): JDK includes JRE. JRE installation on our computers allows the java program to run, however, we cannot compile it. JRE includes a browser, JVM, applet support, and plugins. For running the java program, a computer needs JRE.
Garbage Collector: In Java, programmers can’t delete the objects. To delete or recollect that memory JVM has a program called garbage collectors. Garbage Collectors can recollect the objects that are not referenced. So Java makes the life of a programmer easy by handling memory management. However, programmers should be careful about their code whether they are using objects that have been used for a long time. Because Garbage cannot recover the memory of objects being referenced.
People who write frontend code are referred to as frontend developers.
Frontend developers use technologies like HTML, CSS, and frontend JavaScript frameworks like React to write programs.
Backend development
Backend development mainly involves writing what is known as “business logic”—how information is passed between the frontend and backend.
The “backend” is the part of the software that the user cannot see. When a user clicks “login,” for example, they’re not able to see the database where their login data is stored.
In this sense, the backend is more abstract.
A backend web developer writes code that dictates how information flows, for example, between the user and the database.