Pros of SpotBugs

• Lightweight and focused specifically on Java bytecode analysis
• Can be easily integrated into build processes and IDEs
• Free and open-source with a large community of contributors

Cons of SpotBugs

• Limited to Java language analysis only
• Less comprehensive in terms of overall code quality metrics
• Requires more manual configuration compared to SonarQube's out-of-the-box setup

Code Comparison

SpotBugs configuration (in Maven pom.xml):

<plugin>
  <groupId>com.github.spotbugs</groupId>
  <artifactId>spotbugs-maven-plugin</artifactId>
  <version>4.5.0.0</version>
</plugin>

SonarQube configuration (in Maven pom.xml):

<plugin>
  <groupId>org.sonarsource.scanner.maven</groupId>
  <artifactId>sonar-maven-plugin</artifactId>
  <version>3.9.1.2184</version>
</plugin>

Both tools can be integrated into Maven builds, but SonarQube offers a more comprehensive analysis across multiple languages and metrics, while SpotBugs focuses specifically on Java bytecode analysis for finding bugs.

Pros of PMD

• Lightweight and easy to integrate into existing build processes
• Supports multiple programming languages beyond Java
• Highly customizable with user-defined rules

Cons of PMD

• Less comprehensive analysis compared to SonarQube
• Limited reporting and visualization capabilities
• Requires more manual configuration for advanced use cases

Code Comparison

PMD rule definition:

<rule name="AvoidUsingHardCodedIP"
      language="java"
      message="Avoid using hardcoded IP addresses"
      class="net.sourceforge.pmd.lang.rule.XPathRule">
    <description>
        Avoid using hardcoded IP addresses in code.
    </description>
    <priority>3</priority>
    <properties>
        <property name="xpath">
            <value>
                //Literal[matches(@Image, "^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$")]
            </value>
        </property>
    </properties>
</rule>

SonarQube rule definition:

@Rule(key = "S1313")
public class HardcodedIpAddressCheck extends IssuableSubscriptionVisitor {
    private static final String MESSAGE = "Make this IP '%s' address configurable.";
    private static final Pattern IP = Pattern.compile("^(?:[0-9]{1,3}\\.){3}[0-9]{1,3}$");

    @Override
    public List<Tree.Kind> nodesToVisit() {
        return ImmutableList.of(Tree.Kind.STRING_LITERAL);
    }

    @Override
    public void visitNode(Tree tree) {
        LiteralTree literal = (LiteralTree) tree;
        if (IP.matcher(LiteralUtils.trimQuotes(literal.value())).matches()) {
            reportIssue(literal, String.format(MESSAGE, literal.value()));
        }
    }
}

Pros of Checkstyle

• Lightweight and focused solely on Java code style checking
• Highly customizable with extensive rule sets
• Easy integration with build tools like Maven and Gradle

Cons of Checkstyle

• Limited to Java language only
• Lacks advanced static code analysis features
• No built-in reporting or visualization tools

Code Comparison

Checkstyle configuration example:

<module name="Checker">
  <module name="TreeWalker">
    <module name="AvoidStarImport"/>
    <module name="ConstantName"/>
  </module>
</module>

SonarQube configuration example:

sonar.projectKey=my:project
sonar.projectName=My project
sonar.projectVersion=1.0
sonar.sources=src
sonar.java.binaries=target/classes

Summary

Checkstyle is a lightweight, Java-specific code style checker that excels in customization and easy integration with build tools. It's ideal for projects focused solely on Java code style enforcement. However, it lacks the comprehensive static code analysis and multi-language support offered by SonarQube.

SonarQube, on the other hand, provides a more robust solution for code quality management across multiple languages, with advanced static analysis features and built-in reporting tools. It's better suited for larger projects or organizations requiring a more comprehensive code quality platform.

Pros of detekt

• Lightweight and focused specifically on Kotlin static code analysis
• Easy integration with Gradle and Maven build systems
• Highly customizable with the ability to write custom rules

Cons of detekt

• Limited to Kotlin language analysis only
• Smaller community and fewer out-of-the-box rules compared to SonarQube
• Less comprehensive reporting and visualization features

Code Comparison

detekt configuration example:

detekt {
    config = files("$projectDir/config/detekt.yml")
    buildUponDefaultConfig = true
    allRules = false
}

SonarQube configuration example:

sonar.projectKey=my:project
sonar.sources=src
sonar.java.binaries=build/classes
sonar.kotlin.detekt.reportPaths=build/reports/detekt/detekt.xml

Summary

detekt is a lightweight, Kotlin-specific static code analysis tool that integrates easily with build systems. It offers high customizability but has a narrower focus compared to SonarQube. SonarQube, on the other hand, provides a more comprehensive analysis across multiple languages and offers advanced reporting features, but may be considered heavier and more complex to set up for smaller projects.