What is Package in Java - Types, Uses & Work

A package in Java is a namespace that groups related classes, interfaces, and sub-packages together. Packages help organize large codebases and prevent naming conflicts between classes.

Creating a Package

package com.uncodemy.app;

public class Student {
    void display() {
        System.out.println("Inside Student class");
    }
}

Using a Package

import com.uncodemy.app.Student;

public class Main {
    public static void main(String[] args) {
        Student s = new Student();
        s.display();
    }
}

Types of Packages

• Built-in Packages — provided by Java itself, such as java.util, java.io, and java.lang
• User-defined Packages — packages created by developers to organize their own classes

How Packages Work

• The package statement must be the first line in a Java source file
• Packages map to a directory structure on disk, matching the package name
• Classes in the same package can access each other without an explicit import
• Classes from other packages need to be imported using the import keyword

Why Use Packages?

• Avoids naming conflicts between classes with the same name in different modules
• Makes large applications easier to navigate and maintain
• Controls access using access modifiers alongside package boundaries