StreamCalculator Project

Overview

The StreamCalculator project is a Java application that demonstrates the use of Java Streams for functional programming. It provides a series of utility methods for manipulating lists of integers through various functional operations like filtering, mapping, sorting, and reducing. The project includes both an incomplete implementation (StreamCalculator.java) and a fully implemented solution (StreamCalculator_solution.java).

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Features

Core Functionality

• Stream Conversion

  • getStream() - Converts a list of integers into a stream.
  • getList() - Retrieves the list of integers.

• Stream Operations

  • Sorting: Sort the list in ascending order.
  • Filtering: Filter integers within a specific range.
  • Mapping: Add a constant value to each element of the list.
  • Reduction:
    • sum() - Calculates the sum of all integers.
    • product() - Calculates the product of all integers.

• Utility Methods

  • print(String separator) - Prints the list with elements separated by a given delimiter.

• Composed Operations

  • addAndSum(Integer value) - Adds a constant value to each integer in the list and computes the sum.

Bonus

• sumParallel() - Computes the sum of integers using parallel streams for improved performance with large datasets.

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Files

StreamCalculator.java

This is a skeleton implementation of the project, containing placeholders and comments for each required feature. It serves as a template for the assignment.

StreamCalculator_solution.java

This file contains the complete implementation of all required functionalities, including bonus features. It serves as a reference for the expected behavior.

.gitignore

The .gitignore file ensures that IDE-specific and temporary files are excluded from version control. It includes configurations for IntelliJ IDEA, Eclipse, NetBeans, VS Code, and common temporary files like .DS_Store.

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How to Run

1. Compile the Solution: Ensure you have the Java Development Kit (JDK) installed.

   javac StreamCalculator_solution.java

2. Run the Application:

   java StreamCalculator_solution

3. The program will:

   • Validate the correctness of methods.
   • Demonstrate the use of filtering, mapping, and reducing operations.
   • Test the sumParallel method with a list of 100 randomly generated integers.

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Requirements

• Java Version: JDK 8 or later (for Stream API support).
• IDE Support: Compatible with IntelliJ IDEA, Eclipse, or any Java-capable editor.

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Example Usage

Input

List<Integer> numbers = Arrays.asList(17, 11, 19, 13, 43, 37, 41, 31, 29, 97, 5, 3, 7, 23);
StreamCalculator_solution calc = new StreamCalculator_solution(numbers);
calc.filter(2, 30);
calc.print(", ");

Output

17, 11, 19, 13, 29, 5, 3, 7,

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Contribution

This project is designed for educational purposes, encouraging hands-on learning with Java Streams. If you have ideas for enhancements, feel free to contribute by submitting a pull request.

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License

This project is open source and available under the MIT License.