How to Compile and Run a Java Program on Mac

What are the steps to compile and run a Java program on my Mac?

Compiling and running a Java program on your Mac involves setting up the Java Development Kit (JDK), writing your Java code, compiling it into bytecode, and then executing it using the Java Virtual Machine (JVM).

// Sample Java program
public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
} // Save as HelloWorld.java

// Compilation command in terminal:
$ javac HelloWorld.java

// Execution command in terminal:
$ java HelloWorld

Causes

• Java Development Kit (JDK) is not installed.
• Incorrect path settings in your system environment variables.
• Mistakes in your Java code prevent successful compilation.

Solutions

• Download and install the latest JDK from the official Oracle website or adopt OpenJDK.
• Set your JAVA_HOME environment variable correctly to point to the JDK installation directory.
• Use a text editor like TextWrangler or Visual Studio Code to write your Java code, ensuring correct syntax and structure.

Mistake: Forgetting to save the Java file with the '.java' extension.

Solution: Ensure you save your file with the appropriate naming, e.g., HelloWorld.java.

Mistake: Running the program from a different directory than where the file is saved.

Solution: Navigate to the directory where your Java file is located using the 'cd' command before compiling or running.

Mistake: Missing the JDK installation or incorrect version.

Solution: Verify that the JDK is installed by running 'java -version' and 'javac -version' in your terminal.