Java and Bazel

This page contains resources that help you use Bazel with Java projects. It links to a tutorial, build rules, and other information specific to building Java projects with Bazel.

Contents

Working with Bazel

The following resources will help you work with Bazel on Java projects:

Migrating to Bazel

If you currently build your Java projects with Maven, follow the steps in the migration guide to start building your Maven projects with Bazel:

Best practices

In addition to general Bazel best practices, below are best practices specific to Java projects.

Directory structure

Prefer Maven’s standard directory layout (sources under src/main/java, tests under src/test/java).

BUILD files

Follow these guidelines when creating your BUILD files:

  • Use one BUILD file per package containing Java sources.

  • Every BUILD file should contain one java_library rule that looks like this:

    java_library(
    name = "directory-name",
    srcs = glob(["*.java"]),
    deps = [...],
)

  • The name of the library should be the name of the directory containing the BUILD file.

  • The sources should be a non-recursive glob of all Java files in the directory.

  • Tests should be in a matching directory under src/test and depend on this library.

Java and new rules

Note: Creating new rules is for advanced build and test scenarios. You do not need it when getting started with Bazel.

The following modules, configuration fragments, and providers will help you extend Bazel’s capabilities when building your Java projects: