Master Java Code Quality: CheckStyle, PMD, FindBugs & SonarLint

1. Alibaba Java Coding Guidelines

1.1 Overview

Alibaba Java Coding Guidelines focuses on Java code conventions, providing real‑time inspection and categorizing violations as Blocker, Critical, or Major, many of which can be auto‑fixed.

1.2 Scanning Scope

OOP rules

Concurrency handling

Control statements

Naming conventions

Constant definitions

Comment standards

1.3 Installation

File > Settings > Plugins > Marketplace

– search “Alibaba Java Coding Guidelines”, install and restart.

1.4 Usage

1.1 Run

(1) Tools > Alibaba Coding Guidelines > Scan

(2) Right‑click in editor or project view and choose “Coding Guidelines Scan”.

1.5 Toolbar Functions

Rerun Inspection

– re‑run the scan Close – close the AJCG panel Expand All – expand result tree Collapse All – collapse result tree Go Pre Problem – previous issue Go Next Problem – next issue

Group by Severity

Group by Directory

Filter Resolved Items

Autoscroll to Source

Export

– export results as XML or HTML Edit Settings – edit plugin settings

2. CheckStyle

2.1 Overview

CheckStyle checks coding style and format, such as naming, Javadoc, whitespace, method length, duplicate code, and unused imports, helping developers follow style guidelines; it has limited bug‑detection capability.

2.2 Installation

File > Settings > Plugins > Marketplace

– search “CheckStyle”, install and restart.

2.3 Usage

After installation, the plugin shows style violations in the editor; most issues are related to indentation and formatting.

3. PMD

3.1 Overview

PMD focuses on security‑related coding rules and provides data‑flow and path analysis. It supports custom rules and detects potential bugs, dead code, misuse of String/StringBuffer, complex expressions, duplicated code, object creation inside loops, and resource leaks.

3.2 Installation

File > Settings > Plugins > Marketplace

– search “PMDPlugin”, install and restart.

3.3 Usage

Run via Tools > Run PMD to scan the whole project, or right‑click a file/package and choose “Run PMD” for a selected scope.

Result panel shows rule sets, custom rules, and detected issues. Configuration can be opened via File > Settings > Other Settings > PMD.

4. FindBugs

4.1 Overview

FindBugs detects runtime bugs such as null‑pointer dereferences, unreleased resources, and incorrect string comparisons, providing suggestions for fixes.

4.2 Installation

File > Settings > Plugins > Marketplace

– search “FindBugs”, install and restart.

4.3 Usage

Analyze a file, package, module, or whole project via right‑click and selecting the appropriate scope.

The result panel lists issues; clicking an item jumps to the offending code.

5. SonarLint

5.1 Overview

SonarLint extends static analysis beyond bugs to code quality, dependencies, coupling, and complexity, offering richer rules than FindBugs.

5.2 Installation

File > Settings > Plugins > Marketplace

– search “SonarLint”, install and restart.

5.3 Usage

Right‑click a project or file and run SonarLint; issues appear in the report with suggested fixes. The plugin can also be linked to a SonarQube server for server‑side analysis.

Configure server connection and project selection via the plugin settings.

Conclusion

For coding‑style checks, use Alibaba Java Coding Guidelines.

For bug detection, combine PMD, FindBugs, and SonarLint; PMD offers strong custom‑rule support, FindBugs excels at bug discovery, and SonarLint provides comprehensive quality rules.