java@v1

Hygiene checks for Java projects (Maven + Gradle). Adopt it with:

extends:
  - alint://bundled/java@v1

Gated with when: facts.has_java (true if any Java build manifest exists anywhere in the tree) plus a per-rule scope_filter: { has_ancestor: [pom.xml, build.gradle, build.gradle.kts] } on per-file content rules so they only apply to files inside a Java module — useful in polyglot monorepos where Java modules sit alongside Rust / Node / Python subdirectories.

Build outputs (target/ for Maven, build/ for Gradle) are checked with git_tracked_only: true so a developer’s locally-built artefacts don’t trigger the rule — only committed contents do, which is the actual hygiene we care about.

Rules

`java-manifest-exists`

kind: file_exists
level: error
when: facts.has_java
policy: https://maven.apache.org/guides/introduction/introduction-to-the-pom.html

Java project: pom.xml (Maven) or build.gradle / build.gradle.kts (Gradle) at the root is required.

`java-build-wrapper-committed`

kind: file_exists
level: info
when: facts.has_java
policy: https://docs.gradle.org/current/userguide/gradle_wrapper.html

A committed build wrapper (mvnw for Maven, gradlew for Gradle) lets contributors and CI build the project without pre-installing the right Maven / Gradle version.

`java-no-tracked-target`

kind: dir_absent
level: error
when: facts.has_java

Maven’s target/ is a build directory and shouldn’t be committed. Add target/ to your .gitignore.

`java-no-tracked-build`

kind: dir_absent
level: error
when: facts.has_java

Gradle’s build/ is a build directory and shouldn’t be committed. Add build/ to your .gitignore.

`java-no-class-files`

kind: file_absent
level: error
when: facts.has_java

Compiled .class files don’t belong in version control. Build them from the .java sources instead.

`java-sources-pascal-case`

kind: filename_case
level: warning
when: facts.has_java

Java filenames should match the public class name (PascalCase).

`java-sources-final-newline`

kind: final_newline
level: info
when: facts.has_java

`java-sources-no-trailing-whitespace`

kind: no_trailing_whitespace
level: info
when: facts.has_java

`java-sources-no-bidi`

kind: no_bidi_controls
level: error
when: facts.has_java
policy: https://trojansource.codes/

Trojan Source (CVE-2021-42574): bidi override chars in Java sources are rejected.

`java-sources-no-zero-width`

kind: no_zero_width_chars
level: error
when: facts.has_java

Zero-width characters in Java sources are rejected (review hazard).

Source

The full ruleset definition is committed at crates/alint-dsl/rulesets/v1/java.yml in the alint repo (the snapshot below is generated verbatim from that file).

# alint://bundled/java@v1
#
# Hygiene checks for Java projects (Maven + Gradle). Adopt it
# with:
#
#     extends:
#       - alint://bundled/java@v1
#
# Gated with `when: facts.has_java` (true if any Java build
# manifest exists anywhere in the tree) plus a per-rule
# `scope_filter: { has_ancestor: [pom.xml, build.gradle,
# build.gradle.kts] }` on per-file content rules so they only
# apply to files inside a Java module — useful in polyglot
# monorepos where Java modules sit alongside Rust / Node /
# Python subdirectories.
#
# Build outputs (`target/` for Maven, `build/` for Gradle) are
# checked with `git_tracked_only: true` so a developer's
# locally-built artefacts don't trigger the rule — only
# committed contents do, which is the actual hygiene we care
# about.

version: 1

facts:
  - id: has_java
    any_file_exists:
      - pom.xml
      - "**/pom.xml"
      - build.gradle
      - "**/build.gradle"
      - build.gradle.kts
      - "**/build.gradle.kts"
      - settings.gradle
      - "**/settings.gradle"
      - settings.gradle.kts
      - "**/settings.gradle.kts"

rules:
  # --- Manifest -----------------------------------------------------
  - id: java-manifest-exists
    when: facts.has_java
    # Maven (`pom.xml`) or Gradle (Groovy or Kotlin DSL). Either
    # is fine; mixed setups are unusual but valid.
    kind: file_exists
    paths:
      - pom.xml
      - build.gradle
      - build.gradle.kts
    root_only: true
    level: error
    message: >-
      Java project: `pom.xml` (Maven) or `build.gradle` /
      `build.gradle.kts` (Gradle) at the root is required.
    policy_url: "https://maven.apache.org/guides/introduction/introduction-to-the-pom.html"

  # --- Wrapper scripts for reproducible builds ----------------------
  - id: java-build-wrapper-committed
    when: facts.has_java
    # `mvnw` (Maven Wrapper) or `gradlew` (Gradle Wrapper) make
    # CI builds and contributor onboarding deterministic. Either
    # script suffices.
    kind: file_exists
    paths:
      - mvnw
      - gradlew
    root_only: true
    level: info
    message: >-
      A committed build wrapper (`mvnw` for Maven, `gradlew` for
      Gradle) lets contributors and CI build the project without
      pre-installing the right Maven / Gradle version.
    policy_url: "https://docs.gradle.org/current/userguide/gradle_wrapper.html"

  # --- Build outputs must not be committed --------------------------
  # We use `git_tracked_only: true` here so the rule only fires
  # if `target/` is *committed* — a developer's locally-built
  # `target/` (gitignored, no tracked content) is silently OK.
  # Same shape for Gradle's `build/`.
  - id: java-no-tracked-target
    when: facts.has_java
    kind: dir_absent
    paths: "**/target"
    git_tracked_only: true
    level: error
    message: >-
      Maven's `target/` is a build directory and shouldn't be
      committed. Add `target/` to your `.gitignore`.

  - id: java-no-tracked-build
    when: facts.has_java
    kind: dir_absent
    paths: "**/build"
    git_tracked_only: true
    level: error
    message: >-
      Gradle's `build/` is a build directory and shouldn't be
      committed. Add `build/` to your `.gitignore`.

  - id: java-no-class-files
    when: facts.has_java
    kind: file_absent
    paths: "**/*.class"
    git_tracked_only: true
    level: error
    message: >-
      Compiled `.class` files don't belong in version control.
      Build them from the `.java` sources instead.

  # --- Source-file conventions --------------------------------------
  - id: java-sources-pascal-case
    when: facts.has_java
    # Java's class-file convention: every public top-level type
    # lives in a file named after it, in PascalCase. Some
    # repositories ship `package-info.java` / `module-info.java`
    # (lowercase, snake-shaped) — those are the only standard
    # exceptions, so we exclude them.
    kind: filename_case
    paths:
      include: ["**/*.java"]
      exclude:
        - "**/package-info.java"
        - "**/module-info.java"
    case: pascal
    level: warning
    message: "Java filenames should match the public class name (PascalCase)."

  - id: java-sources-final-newline
    when: facts.has_java
    kind: final_newline
    paths: "**/*.java"
    scope_filter:
      has_ancestor: [pom.xml, build.gradle, build.gradle.kts]
    level: info
    fix:
      file_append_final_newline: {}

  - id: java-sources-no-trailing-whitespace
    when: facts.has_java
    kind: no_trailing_whitespace
    paths: "**/*.java"
    scope_filter:
      has_ancestor: [pom.xml, build.gradle, build.gradle.kts]
    level: info
    fix:
      file_trim_trailing_whitespace: {}

  # --- Trojan Source defense on Java sources ------------------------
  - id: java-sources-no-bidi
    when: facts.has_java
    kind: no_bidi_controls
    paths: "**/*.java"
    scope_filter:
      has_ancestor: [pom.xml, build.gradle, build.gradle.kts]
    level: error
    message: "Trojan Source (CVE-2021-42574): bidi override chars in Java sources are rejected."
    policy_url: "https://trojansource.codes/"

  - id: java-sources-no-zero-width
    when: facts.has_java
    kind: no_zero_width_chars
    paths: "**/*.java"
    scope_filter:
      has_ancestor: [pom.xml, build.gradle, build.gradle.kts]
    level: error
    message: "Zero-width characters in Java sources are rejected (review hazard)."