Installation and Setup

1. Downloading Java:

   • Visit the official Oracle website to download the latest Java Development Kit (JDK). Alternatively, you can use open-source distributions like OpenJDK.

2. Installation:

   • Windows: Run the downloaded installer and follow the on-screen instructions to install the JDK.
   • macOS: Use the installer package or Homebrew to install Java.
     

     brew install openjdk

   • Linux: Install Java using the package manager. For example, on Ubuntu:
     

     sudo apt update

     sudo apt install openjdk-11-jdk


3. Setting Up the Environment:

   • Environment Variables: Set up environment variables to ensure the Java compiler and runtime are accessible from the command line.
     • On Windows, add JAVA_HOME and update the PATH variable.
     • On macOS and Linux, add the following lines to your .bashrc or .zshrc file:
       

       export JAVA_HOME=/path/to/jdk

       export PATH=$JAVA_HOME/bin:$PATH


4. Verifying Installation:

   • Verify the installation by running:
     

     java -version

     javac -version


Writing Your First Java Program

1. Hello World Program:

   • Create a new file named HelloWorld.java and add the following code:
     

     public class HelloWorld {

     public static void main(String[] args) {
System.out.println("Hello, World!");
}
}


2. Compiling the Program:

   • Compile the program using the javac command:
     

     javac HelloWorld.java

3. Running the Program:

   • Run the compiled bytecode using the java command:
     

     java HelloWorld

Using Java

1. Developing Applications:

   • IDE Support: Use Integrated Development Environments (IDEs) like IntelliJ IDEA, Eclipse, or NetBeans for enhanced productivity, debugging, and code completion features.
   • Build Tools: Utilize build tools such as Maven or Gradle to manage project dependencies, build processes, and deployments.

2. Key Concepts:

   • Classes and Objects: Define classes to create objects, encapsulating data and behavior.
   • Inheritance: Use inheritance to create a hierarchy of classes that share common behavior.
   • Interfaces and Abstract Classes: Define interfaces and abstract classes to establish contracts for what a class can do, without dictating how it should do it.

3. Advanced Features:

   • Generics: Use generics to create classes, interfaces, and methods with type parameters for stronger type checks at compile time.
   • Lambda Expressions and Streams: Simplify functional programming with lambda expressions and use the Streams API for operations on collections.