Java LongStream min() Method

The min() method in Java, part of the java.util.stream.LongStream interface, is used to find the minimum element in the stream. This method is useful when you need to determine the lowest value in a stream of long values.

Table of Contents

1. Introduction
2. min() Method Syntax
3. Understanding min()
4. Examples
   • Basic Usage
   • Using min() with Filtered Streams
5. Real-World Use Case
6. Conclusion

Introduction

The min() method is a terminal operation that returns an OptionalLong describing the minimum element of the stream, or an empty OptionalLong if the stream is empty. This method is particularly useful for finding the lowest value in a stream of long values.

min() Method Syntax

The syntax for the min() method is as follows:

OptionalLong min()

Parameters:

• This method does not take any parameters.

Returns:

• An OptionalLong describing the minimum element of the stream, or an empty OptionalLong if the stream is empty.

Throws:

• This method does not throw any exceptions.

Understanding min()

The min() method processes each element of the stream to determine the minimum value. If the stream is empty, it returns an empty OptionalLong. If the stream contains elements, it returns an OptionalLong containing the minimum value.

Examples

Basic Usage

To demonstrate the basic usage of min(), we will create a LongStream and use min() to find the minimum element.

Example

import java.util.OptionalLong;
import java.util.stream.LongStream;

public class MinExample {
    public static void main(String[] args) {
        LongStream stream = LongStream.of(1L, 2L, 3L, 4L, 5L);

        // Use min() to find the minimum element
        OptionalLong minElement = stream.min();

        // Print the minimum element if present
        minElement.ifPresent(System.out::println);
    }
}

Output:

1

Using min() with Filtered Streams

This example shows how to use min() in combination with filtering to find the minimum value among elements that match a specific condition.

Example

import java.util.OptionalLong;
import java.util.stream.LongStream;

public class MinWithFilterExample {
    public static void main(String[] args) {
        LongStream stream = LongStream.of(10L, 20L, 30L, 40L, 50L);

        // Use min() to find the minimum element greater than 25
        OptionalLong minElement = stream.filter(n -> n > 25).min();

        // Print the minimum element if present
        minElement.ifPresent(System.out::println);
    }
}

Output:

30

Real-World Use Case

Finding the Minimum Transaction Amount

In real-world applications, the min() method can be used to find the lowest transaction amount from a stream of transaction values.

Example

import java.util.OptionalLong;
import java.util.stream.LongStream;

public class MinTransactionExample {
    public static void main(String[] args) {
        LongStream transactionAmounts = LongStream.of(1000L, 2000L, 1500L, 3000L, 2500L);

        // Use min() to find the lowest transaction amount
        OptionalLong minTransaction = transactionAmounts.min();

        // Print the lowest transaction amount if present
        minTransaction.ifPresent(amount -> System.out.println("Lowest Transaction Amount: " + amount));
    }
}

Output:

Lowest Transaction Amount: 1000

Conclusion

The LongStream.min() method is used to find the minimum element in the stream. This method is particularly useful for determining the lowest value in a stream of long values. By understanding and using this method, you can efficiently manage and process streams of values in your Java applications, ensuring that the minimum value is correctly identified.