1. Introduction

Finding the minimum element in a List is a frequent requirement in Java. This can be achieved using the Collections.min() method or by utilizing Java 8 streams. This tutorial will guide you on how to find the minimum element in a List employing both techniques.

2. Program Steps

1. Import the necessary libraries.

2. Create a List of integers.

3. Find the minimum element using the Collections.min() method.

4. Find the minimum element using Java 8 stream’s min() method.

5. Output the results.

3. Code Program

// Step 1: Import the necessary libraries
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Optional;

public class FindMinInList {

    public static void main(String[] args) {

        // Step 2: Create a List of integers
        List<Integer> numbers = Arrays.asList(1, 3, 7, 9, 12, 5);

        // Step 3: Find the minimum element using the Collections.min() method
        Integer minNumberUsingCollections = Collections.min(numbers);

        // Step 4: Find the minimum element using Java 8 stream’s min() method
        Optional<Integer> minNumberUsingStream = numbers.stream().min(Integer::compare);

        // Step 5: Output the results
        System.out.println("Minimum number using Collections.min(): " + minNumberUsingCollections);
        System.out.println("Minimum number using Stream.min(): " + (minNumberUsingStream.isPresent() ? minNumberUsingStream.get() : "List is empty"));
    }
}

Output:

Minimum number using Collections.min(): 1
Minimum number using Stream.min(): 1

4. Step By Step Explanation

Step 1: Import the required classes and interfaces from Java libraries.

Step 2: Instantiate a List of integers with some values.

Step 3: Utilize the Collections.min() method to find the minimum element in the list.

Step 4: Employ the Java 8 stream’s min() method along with Integer::compare to find the minimum element in the list. The min() method returns an Optional, hence it's important to handle the scenario where the List is empty.

Step 5: Display the minimum number determined by both methods to the console.