Implementation:SeleniumHQ Selenium ModuleGenerator

Knowledge Sources	SeleniumHQ_Selenium
Domains	WebDriver, Build_Tooling
Last Updated	2026-02-12 00:00 GMT

Overview

ModuleGenerator is a Bazel build tool that generates Java Platform Module System (JPMS) module-info.class descriptors for Selenium JAR artifacts.

Description

The ModuleGenerator class automates the creation of Java module descriptors (module-info.class) for Selenium's modular JAR files. It works by:

1. Accepting an input JAR, a module name, and configuration flags (exports, hides, uses, opens-to, module-path).
2. Running the JDK's jdeps tool with --generate-module-info to produce an initial module-info.java from the input JAR.
3. Parsing the generated module-info.java using JavaParser to obtain the module declaration AST.
4. Customizing the module declaration by setting the module name, open status, exported/hidden packages, uses directives (including those detected by scanning for ServiceLoader.load() calls via ASM bytecode analysis), and opens directives.
5. Compiling the final module descriptor to bytecode using ByteBuddy's ASM ClassWriter and ModuleVisitor.
6. Writing the resulting module-info.class into an output JAR.

The tool also handles automatic module name normalization (stripping processed_ prefixes added by Bazel), marks non-Selenium/non-JDK modules as static (so users can optionally exclude transitive dependencies), and infers packages from class entries in the input JAR (including multi-release JAR support).

Usage

This tool is invoked as part of the Bazel build pipeline for Selenium's Java bindings. It is not intended for direct end-user invocation. It is called with command-line flags to produce a module-info JAR that is merged with the main artifact JAR during the build process.

Code Reference

Source Location

• Repository: SeleniumHQ_Selenium
• File: java/src/dev/selenium/tools/modules/ModuleGenerator.java

Signature

public class ModuleGenerator {

    public static void main(String[] args) throws IOException

    private static Collection<String> readServicesFromClasses(Path inJar)

    private static Set<String> inferPackages(Path inJar)

    private static class MyModuleVisitor extends VoidVisitorAdapter<Void> {
        MyModuleVisitor(ClassLoader classLoader, Set<String> packages,
                        Set<String> excluded, ModuleVisitor byteBuddyVisitor)
        public void visit(ModuleRequiresDirective n, Void arg)
        public void visit(ModuleExportsDirective n, Void arg)
        public void visit(ModuleProvidesDirective n, Void arg)
        public void visit(ModuleUsesDirective n, Void arg)
        public void visit(ModuleOpensDirective n, Void arg)
    }
}

Import

import dev.selenium.tools.modules.ModuleGenerator;

I/O Contract

Inputs (Command-Line Flags)

Flag	Type	Required	Description
--in	Path	Yes	Path to the input JAR to analyze
--output	Path	Yes	Path for the output JAR containing module-info.class
--module-name	String	Yes	The Java module name to assign (e.g., org.seleniumhq.selenium.api)
--module-path	Path	No (repeatable)	JARs to include on the module path for jdeps analysis
--exports	String	No (repeatable)	Package names to export; if omitted, all packages except hidden ones are exported
--hides	String	No (repeatable)	Package names to hide (not export)
--uses	String	No (repeatable)	Fully-qualified service interface names for uses directives
--is-open	Boolean	No	Whether the module is an open module
--open-to	String	No (repeatable)	Module names to open all exported packages to
--opens-to	String String	No (repeatable)	Package and target module for specific opens directives

Output

Artifact	Description
Output JAR	A JAR containing a single module-info.class with the generated JPMS module descriptor

Usage Examples

# Typical invocation via Bazel (conceptual, not run directly):
java -cp <classpath> dev.selenium.tools.modules.ModuleGenerator \
  --in bazel-bin/java/src/org/openqa/selenium/libapi.jar \
  --output bazel-bin/java/src/org/openqa/selenium/module-info.jar \
  --module-name org.seleniumhq.selenium.api \
  --module-path third_party/guava.jar \
  --exports org.openqa.selenium \
  --exports org.openqa.selenium.logging \
  --hides org.openqa.selenium.internal \
  --uses org.openqa.selenium.remote.locator.CustomLocator

Related Pages

• SeleniumHQ_Selenium_Bazel_Build_And_Go_Wrapper - Bazel build and Go wrapper tooling
• SeleniumHQ_Selenium_CdpClientGenerator - Another Java code generation build tool
• SeleniumHQ_Selenium_Architecture - Overall Selenium architecture