Java fundamentals

The Java language is selected to create websites, mobile applications, custom software, electronic portals, etc., and is considered as one of the most popular programming languages ​​in the world nowaday. Many software developers had started with Java and still used it until now. Java is the default program in operating systems and has a huge influence to us.

What is Java?

Java is a high-level programming language, developed by Sun Microsystems, initiated by James Gosling and released in 1995 as a core component of the Java platform of Sun Microsystems (Java 1.0 [J2SE]). Java runs on many different platforms, such as Windows, Mac and different versions of UNIX.

Java is considered as a kind of object-oriented programming language (OOP) and class-based. Unlike normal programming languages, Java is designed to compile source code into bytecode instead of compiling source code into machine code or directly translating source code when running. After that, the bytecode will be implemented by the runtime environment.

Characteristics of Java

• Object-oriented: In Java, everything is Object. Java can be expanded because it is based on the Object model.
• Independent platform: Unlike many other programming languages ​​(C, C ++), when Java is compiled, it does not compile to a specific computer on any platform, instead of independent code bytes with platform. This Byte code is distributed on the web and translated by the Virtual Machine (JVM) on any platform it is running.
• Simple: Java is designed to be easy to learn. If you basically understand the concept of Java object-oriented programming, it is possible to learn this language very quickly.
• Security: With Java's security features, it allows the development of systems without viruses and forgeries. Authentication techniques based on public encryption.
• Neutral architecture: Java compiler creates an object file format that has a neutral architecture, making the compiled code can run on multiple processors, with the presence of the Java runtime system.
• Portable: Being a neutral and independent architecture is the most important feature when talking about the Portable aspect of Java. The Java compiler is written in ANSI C with a neat portable boundary, which is a POSIX subset (flexible operating system interface). You can bring the Java code byte to any platform.
• Powerful: Java attempts to eliminate error-prone situations by emphasizing mainly compile-time error checking and runtime checking.
• Multithreading: With Java's multithreading feature, you can write programs that can perform multiple tasks simultaneously. This feature allows developers to build interactive applications that can run smoothly.
• Interpretation: Java's Byte code is translated directly to the original platform and it is not stored anywhere.
• High performance: Using Just-In-Time compiler, Java allows execution with high performance, fast detection and debugging.
• Distributed: Java is designed for the distributed environment of the Internet.
• Flexibility: Java is considered more dynamic than C or C ++ because it is designed to adapt to a growing environment. Java programs can carry a large amount of run-time information, which is used to verify and resolve access to objects at runtime.
  JAVA application

Applications of Java

There are four main types of applications that can be created using the Java programming language:

• Standalone App
  
  It is also known as the Destop App or Windows-based App. An application that we need to install on each device such as media player, antivirus, ... AWT and Swing is used in Java to create Standalone App.
• Web App
  
  An application that runs on Server Side and creates Dynamic Page, is called Web App. Currently, Servlet, JSP, Struts, JSF technologies ... are used to create Web App in Java.
• Enterprise App
  A form application like Banking App, has the advantage of high security, load balancing (load balancing) and clustering. In java, EJB is used to create the Enterprise App.
• Mobile App
  
  This is the type of application created for mobile devices. Currently, Android and Java ME are used to create this type of application.

Objective of the course.

• Familiarize yourself with the Java language and know how to write Java programs.
• Know how to declare and use variables and data types.
• Using operators in Java
• Know and use some basic knowledge of the Java language such as:
  • Conditional statement.
  • Loop.
  • Array structure.
  • Strings and StringBuilder
  • Collections
• Method of arithmetic handling in Java
• Can write and use functions in Java.