November 2023 - Java Code Gists

Java Reflection API: Best Practices and Performance Considerations

November 20, 2023 by T Tak

Explore best practices and performance considerations for using the Java Reflection API, including practical Java code examples and insights into maintaining application integrity.

Advanced Singleton Implementations in Java: Thread-Safe and Bill Pugh Methods

November 20, 2023November 20, 2023 by T Tak

Explore advanced Singleton implementations in Java, including Thread-Safe and Bill Pugh methods, with code examples.

Implementing Singleton Design Pattern in Java: Lazy and Eager Initialization

November 20, 2023November 20, 2023 by T Tak

Learn about Lazy and Eager Initialization methods for implementing the Singleton pattern in Java.

Understanding Mockito.when(): Enhancing Java Unit Tests

November 20, 2023November 20, 2023 by T Tak

Explore the use of Mockito.when() in Java unit testing, a key method for stubbing and defining behaviors of mock objects in Mockito.

Mocking Dependencies in Unit Tests with Mockito: A Java Example

November 20, 2023November 20, 2023 by T Tak

Learn how to use Mockito to mock dependencies in Java unit tests, focusing on isolating the code under test from its complex dependencies.

Best Practices for Testing Excel File Generation in Java

November 20, 2023November 20, 2023 by T Tak

Testing Excel file generation in Java is an important task to ensure the accuracy and reliability of the data being output. The best way to approach this depends on the complexity of the Excel file you’re generating, but here are some general guidelines and best practices: 1. Unit Testing: Purpose: Verify that individual components (methods/classes) … Read more

Creating a Top-Level Folder in Java

November 20, 2023November 20, 2023 by T Tak

Introduction Creating a top-level folder in Java is a common task that can be easily accomplished using the standard Java I/O libraries. This article demonstrates how to create a top-level folder in Java if it does not already exist, using both the java.io.File class and the java.nio.file package. Using java.io.File

import java.io.File;

public class Main {
    public static void main(String[] args) {
        File folder = new File("TopLevelFolder");
        if (!folder.exists()) {
            boolean created = folder.mkdir();
            if (created) {
                System.out.println("Folder created successfully.");
            } else {
                System.out.println("Unable to create folder.");
            }
        } else {
            System.out.println("Folder already exists.");
        }
    }
}

import java.io.File;

public class Main {

public static void main(String[] args) {

File folder = new File("TopLevelFolder");

if (!folder.exists()) {

boolean created = folder.mkdir();

if (created) {

System.out.println("Folder created successfully.");

} else {

System.out.println("Unable to create folder.");

}

} else {

System.out.println("Folder already exists.");

}

Using java.nio.file (Recommended)

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;

public class Main {
    public static void main(String[] args) {
        Path path = Paths.get("TopLevelFolder");
        if (!Files.exists(path)) {
            try {
                Files.createDirectory(path);
                System.out.println("Folder created successfully.");
            } catch (IOException e) {
                System.out.println("Error occurred: " + e.getMessage());
            }
        } else {
            System.out.println("Folder already exists.");
        }
    }
}

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.io.IOException;

public class Main {

public static void main(String[] args) {

Path path = Paths.get("TopLevelFolder");

if (!Files.exists(path)) {

try {

Files.createDirectory(path);

System.out.println("Folder created successfully.");

} catch (IOException e) {

System.out.println("Error occurred: " + e.getMessage());

}

} else {

System.out.println("Folder already exists.");

}

Best Practices for Managing Test-Generated Files in JUnit

November 20, 2023November 20, 2023 by T Tak

Introduction In JUnit testing, managing files generated by tests is crucial for keeping projects organized and avoiding issues with version control. This article outlines best practices for where to store test-generated files in JUnit tests. 1. Using a Temporary Directory JUnit 5: Use the @TempDir annotation for creating a temporary directory that’s deleted post-testing. JUnit … Read more

Mastering Unit Testing with Mockito: A Beginner’s Guide

November 20, 2023November 20, 2023 by T Tak

Introduction Mockito is a powerful and flexible framework used in Java for creating and using mock objects in unit testing. It offers an easy-to-use API to simulate complex behaviors and interactions, making it a go-to tool for developers looking to implement effective unit testing strategies. This guide provides an introduction to Mockito, illustrating how to … Read more

Configuring Maven Environment: Setting MAVEN_OPTS and M2_HOME in Windows and Linux

November 20, 2023November 19, 2023 by T Tak

Introduction Apache Maven is an essential tool for building and managing Java-based projects. To optimize its performance and ensure its smooth operation, it’s important to correctly set the MAVEN_OPTS and M2_HOME environment variables in your development environment. This article provides a step-by-step guide on configuring these settings in both Windows and Linux systems. 1. Understanding … Read more