Testing Exceptions in Java with JUnit 5

Alexander Obregon
9 min readMay 26, 2024
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Introduction

In modern software development, writing strong and reliable code is a very important skill. One of the key aspects of this is handling and testing exceptions correctly. In Java, exceptions are a fundamental part of error handling, and JUnit 5 provides powerful tools to test them effectively. This tutorial will guide you through the process of testing exceptions in your Java code using JUnit 5, covering various common scenarios with practical examples.

Understanding Exceptions in Java

What are Exceptions?

Exceptions in Java are events that disrupt the normal flow of a program’s execution. They provide a way to signal error conditions and handle them gracefully. When an exception occurs, the normal flow of the program is interrupted, and the runtime system attempts to find an appropriate exception handler. If an exception handler is found, control is transferred to that handler. Otherwise, the program terminates abnormally.

Checked Exceptions

Checked exceptions are exceptions that the Java compiler forces you to handle. They must be either caught or declared in the method signature using the throws keyword. Checked exceptions are typically used for conditions that are outside the…

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Alexander Obregon

Software Engineer, fervent coder & writer. Devoted to learning & assisting others. Connect on LinkedIn: https://www.linkedin.com/in/alexander-obregon-97849b229/