Java is a powerful, high-level, object-oriented programming language created in 1995 by Sun Microsystems (later purchased by Oracle). It has been the go-to language for coding across a variety of platforms, from desktop to mobile and from the web to the cloud. Although Java was originally designed for computer applications, it has since been used for large-scale, enterprise applications for a wide range of businesses. Because of its widespread use, many developers, hobbyists, and organizations have started to use Java to develop their own applications.
What is Java?
Java is a class-based, object-oriented programming language. It is a general-purpose programming language that is extremely popular among web applications and cloud developers due to its ability to deploy in virtually any environment. Java was designed to be much simpler and easier to learn and use than more complex programming languages, making it ideal for beginners. It also supports concurrent programming, and its features help with debugging and improving the overall development process.
Benefits of Learning Java
The biggest benefit of learning Java is that it is open source and free. The code itself is free to use and can be used on multiple platforms, from desktop to mobile and from the web to the cloud. It leverages a vast array of libraries and APIs that can be integrated into your development to create robust applications quickly and efficiently. Additionally, Java facilitates the development of high-performance applications through the use of memory management and optimization techniques.
History of Java
Java was initially released in 1995. It was designed as a core component of Sun Microsystems’ programming environment, Java Development Kit (JDK). It quickly became popular among web and server-side developers since it combines the benefits of both low level C/C++ languages as well as high-level programming languages such as Visual Basic. It gained even more traction after Sun released the Java Runtime Environment (JRE) in 1997, which enabled developers to easily deploy and execute Java programs on multiple platforms.
Popular Java Applications
Java has been used widely by both small and large organizations for developing web and enterprise applications. Major companies like eBay, LinkedIn, Google, and Amazon are amongst the many organizations that make extensive use of Java for their applications. Additionally, Java can also be used for developing embedded devices, games, and enterprise systems for business users.
Java Development Tools
There are several tools available to assist in Java development, such as the various versions of Eclipse IDE and IntelliJ IDEA. These tools help to automate much of the development process, granting developers with increased productivity. Additionally, there are numerous libraries and frameworks available for developers to use in order to rapidly produce their desired application or system. Some of the major frameworks are Spring and Hibernate.
Writing Your First Java Program
Writing your first program in Java can be quite the experience for first time developers. To begin with, you’ll need to have the necessary Java software development kit extracted onto your computer. This kit is available for free online from Oracle, or from any other developer friendly websites. Once you have downloaded it from its location, you’ll need to set up your environment with a few jars. These jars contain some of the most commonly used APIs on the web, allowing you to develop your first Java program.
Java Syntax Basics
Java follows a C-style syntax and uses syntax similar to C/C++ and other popular programming languages. Common keywords include ‘class’, ‘interface’ and ‘package’ as well as standard operator symbols. All source code is written in text editors such as Notepad++. Once written, code has to be compiled by the compiler provided in the Java Development Kit (JDK). Following compilation, the code is run in an interpreter based environment.
Working with Variables and Data Types
When writing Java programs you must declare variables that represent data or objects within the program. Variables come in different data types such as int (integers) or char (character). Different data types hold different amounts of data, so choosing the appropriate data type is essential when writing Java programs. Additionally, being able to correctly assign values to variables is an important concept when working with variables in Java.
Working with Operators and Expressions
Operators are used in all programming languages, including Java. Operators are symbols that tell the compiler or interpreter to perform specific operations on the variables or values within the program. There are several types of operators: arithmetic, logical, assignment, bitwise, etc. Arithmetic operators are used for simple calculations like addition, subtraction, etc. Logical operators are used to compare two statements and create a single statement from them. Assignment operators are used to assign a value to a variable within the program Lastly, bitwise operators are used to perform operations on individual bits within a data type.
Control Flow Statements
Control Flow Statements are used to control when certain lines of code are executed. In Java, this is done with keywords such as ‘if’, ‘for’, ‘while’, ‘switch’, etc. Conditional statements such as ‘if’ check if a certain condition is true or false and if it is true, then the source code runs a certain statement or block; if not then it moves onto the next statement or block. The loop operator ‘for’ on the other hand will execute a certain statement multiple times until a certain condition has been met. Lastly, ‘switch’ is used as an alternative to ‘if’ when there are multiple possible outcomes.
Object-Oriented Programming in Java
Object-oriented programming (OOP) is a programming technique related to classes and objects. Objects are used as containers that contain data as properties and behavior as methods. Classes are blueprints or templates used to create objects from; think of them as a blueprint for a house – you can create multiple houses that all look different but have the same basic blueprint template. OOP helps software developers create more robust programs because objects can be reused to create new programs quickly.
Exception Handling in Java
In Java Exception handling allows developers to handle errors and other exceptions gracefully without crashing their application. Exceptions are treated like any other object in Java so they can be passed around like any other object. Exceptions in Java provide end users with useful information when something goes wrong during runtime while still allowing the user application to continue functioning without disruption.
Generics and Collections in Java
Generics add flexibility when working with classes and collections. A generic class is one that does not accept parameters at compile time but instead uses type parameters which are recognized only at runtime; this feature allows developers to create classes that can handle objects of any type. Additionally, collections provide control over large sets of data or objects; collections is an efficient way of managing an application’s resources by storing them in objects called collections which are capable of organizing them into different useful kinds.
Building Graphical User Interfaces (GUIs) with Swing
Streams, Files, and I/O
Input/output (I/O) operations allow application developers access a wide variety of data sources such as network protocols or files stored on disk or even files stored on another system over a network connection; stream classes provide readers and writers that make these operations simpler by abstracting away all the complicated details of working with files stored on multiple locations. Additionally, files stored on disk can be handled using classes available in the java.io package allowing developers access files on the file system.
Advanced Topics in Java Programming
Advanced topics in Java programming include multi-threading tools such as Synchronized Collections and Futures; debugging tools such as debugging options available with Eclipse IDE; internationalization options allowing applications to support different languages; creating custom Data Structures using Abstract Data Types; utilizing annotations which can be used to add additional functionality to an existing class; building web services using Remote Method Invocation (RMI). Additionally, developers can also build web applications using custom servlets or use different frameworks such as Struts or Spring MVC.