Java.util Package in Java

The java.util package is one of the most widely used packages in the Java programming language. It provides a set of utility classes that support data structures, date and time manipulation, random number generation, event handling, and other commonly used functionalities in Java programs.

• Provides a rich Collection Framework (List, Set, Map) for data handling.
• Includes utility classes (Collections, Arrays) for sorting and searching.
• Offers Date, Calendar, and Random for time and random operations.
• Supports Properties for configuration management.
• Contains concurrent and legacy classes for compatibility.

Package Declaration

import java. util.*;

This single import statement allows access to all classes and interfaces inside the java.util package.

import java.util.*;

public class GFG{

    public static void main(String[] args){

        // Using ArrayList
        List<String> names = new ArrayList<>();
        names.add("Alice");
        names.add("Bob");
        names.add("Charlie");

        // Using Collections utility class
        Collections.sort(names);
        System.out.println("Sorted Names: " + names);

        // Simulated user input
        String userName = "User";
        System.out.println("Hello, " + userName + "!");
    }
}

Sorted Names: [Alice, Bob, Charlie]
Hello, User!

Commonly Used Classes and Interfaces in java.util

Sub-packages of java.util

java.util vs java.lang