11 Most Occurred SonarQube Issues in Java Projects

SonarQube is an industry-leading tool for automating code review and monitoring code quality in many programming languages, including Java. In this article, we explore the most common SonarQube issues in Java code, providing examples and best practices for avoiding and resolving these issues.

1. Code Duplication

Code duplication occurs when identical or similar code blocks are used across different parts of the application. These repeated blocks of code increase complexity, make the code harder to maintain, and may lead to inconsistencies or errors.

Example:

public int task1(int a, int b) {
    return a + b;
}

public int task2(int a, int b) {
    int sum = a  + b;
    return sum;
}

In this example, the task2 method duplicates the addition operation from the task1 method.

Solution: Refactor the code to eliminate duplicate logic, using shared methods or classes to improve reusability and maintainability.

public int task1(int a, int b) {
    return a + b;
}

public int task2(int a, int b) {
    return task1(a, b);
}

2. Unnecessary Imports

Extraneous import statements increase complexity and reduce the readability of the code…