codeguard-java

Java Codeguard Gate

Goal: turn "looks fine" into repeatable tool evidence, and honestly distinguish pass, fail, unverifiable, and planned.

Start in 30 seconds

1. At the repository root, confirm that pom.xml`, `build.gradle or the target file exists.
2. Detect tools:mvn --version。
3. First check read-only:mvn -q javadoc:jar -DskipTests。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform safely fixable items:mvn -q spotless:apply。
6. Rerun lint, and execute the project's existing test/build gates.

You can directly propose:

• "Check this Java project, don't modify anything first, and give me a classification of lint failures."
• "Only fix Java formatting issues; list semantic issues first."
• "Verify Java lint, test, and build evidence before committing."

Capability Boundaries

✅ Good at handling

1. Based on .java and project markers to identify the Java workspace.
2. Run mvn -q javadoc:jar -DskipTests and retain exit codes, scope, and tool versions.
3. Distinguish formatting, static rules, configuration, dependency, and environment-related failures.
4. Use mvn -q spotless:apply to handle reversible issues and rescan.
5. Report local results layered with CI/build/test evidence.

⚠️ Requires conditions

1. The target tool must be installed and its version compatible with project constraints.
2. Must be executed from the correct repository or module root directory.
3. If the project has custom configuration, the committed configuration prevails.
4. Whether generated code, vendor, and cache directories are scanned must follow repository rules.

❌ Not applicable

1. Do not treat formatter passing as compilation, test, or security audit passing.
2. Do not silently install tools, upgrade dependencies, or modify team rules.
3. Do not use suppress/ignore/raising thresholds to hide real problems.
4. Do not claim "check passed" when tools or configuration are missing.

When to use

• The user requests checking or fixing Java code style.
• AI modified .java, and pre-commit verification is needed.
• CI shows failures related to mvn -q javadoc:jar -DskipTests .
• Need to determine whether an issue can be fixed automatically or must be handled manually.

When not to use

• The main task is learning language syntax, framework design, or business modeling; use the corresponding language professional skill instead.
• The main task is dependency vulnerabilities, security audits, or license governance; use dedicated security skills.
• When the user only asks to explain an error and there is no project context, provide a local explanation first and do not claim the repository is all green.

Data and Security

This skill does not collect, upload, send, or store user code and credentials. By default it only reads local repository configuration and runs local tools; it does not install dependencies online, and does not record tokens, passwords, or private source code. Before any automatic fix, inspect the diff first; destructive or large-scale changes must be explicitly confirmed by the user.

Execution Contract

Item	Current Fact
Status	stable(since Codeguard V0.1)
File Extensions	.java
Project Markers	pom.xml, build.gradle
Onboarding Configuration	pom.xml, build.gradle, build.gradle.kts, settings.gradle
Tooling Readiness	Built into the toolchain or declared by the project
Detection Command	使用命令查找与项目配置检查
lint	mvn -q javadoc:jar -DskipTests
format/fix	mvn -q spotless:apply
Project-level gate	mvn -q javadoc:jar -DskipTests

Standard Workflow

Step 1: Determine the Real Scope

Confirm the repository root, module roots, generated directories, vendor directories, and user-specified files. For multi-module projects, list the modules to be scanned first; do not guess based on the current directory.

Step 2: Read the Project Contract

Read pom.xml, build.gradle, build.gradle.kts, settings.gradle and the actual commands in CI. Repository configuration takes precedence over the examples in this skill; if the two conflict, report the difference first.

Step 3: Detect Tools and Versions

Run 对应工具 --version. Missing tools, incompatible versions, or configurations that fail to load are all recorded as "unable to verify", not as passing.

Step 4: Execute Read-Only Checks

Run mvn -q javadoc:jar -DskipTests, recording the command, working directory, exit code, tool version, and the first actionable error.

Step 5: Classify Failures

Type	Typical Signal	Handling
Formatting	Indentation, whitespace, import order	Allow formatter, then check the diff
Static Rules	unused, complexity, naming, dangerous APIs	Minimal semantic fixes, no batch guessing
Configuration	parser/config/schema not found	Fix onboarding or report prerequisites
Environment	command not found, version conflicts	Report installation/version requirements, do not install silently
Internal Tool Errors	crash, timeout, parser exceptions	Preserve the raw evidence, narrow the reproduction scope

Step 6: Controlled Fixes

Prefer running mvn -q spotless:apply. Only handle issues that are certain and reversible; dependency upgrades, rule exemptions, generated files, and business-semantic changes must be explained separately.

Step 7: Verification Loop

Re-run the same lint command, then run the project's existing tests and build. Write "pass" only when the command, scope, and exit code are all clear; otherwise write "not run" or "unable to verify".

Rules

1. Re-verify with the same command: after fixing, the original command that triggered the failure must be re-run.
2. Layered evidence: report lint, format, compile, test, and security separately.
3. Minimal changes: no opportunistic refactoring, do not expand style fixes into business rewrites.
4. Configuration first: do not override the project's existing ignore, dialect, target, or version constraints.
5. No fabrication: tools not run, configurations not seen, and platforms not verified must be clearly marked.

Output Template

Java Codeguard 结果
- 范围：<仓库/模块/文件>
- 工具：<名称与版本>
- 命令：<实际命令>
- 状态：PASS / FAIL / UNVERIFIED / PLANNED
- 发现：<按格式/规则/配置/环境分类>
- 修改：<文件与原因；无修改写 none>
- 复验：<命令、退出码>
- 未验证：<测试/构建/平台差异>

Gotchas

1. Missing tools are not a pass — must output UNVERIFIED and a clear preparation method.
2. A formatter is not a linter — all-green formatting cannot cover up static rule or compilation errors.
3. Root directory determines the result — running in the wrong module may miss detections or load the wrong configuration.
4. Placeholders are not literal arguments — {file} must be replaced with real, authorized paths.
5. Auto-fixes may expand the diff — after fixing, review the diff first, then run the regression gate.
6. Generated and vendor directories require an explicit policy — do not arbitrarily scan or modify third-party content across the whole repository.

Domain pitfalls and fixes

1. Domain pitfall — mvn compile does not run the Javadoc gate; when the release chain fails, you must run it separately mvn javadoc:jar。
2. Domain pitfall — the JDK version changes doclint strictness; local and CI must use the same major version.

When information is insufficient

Do not just say "please provide more information." First give a safe read-only inspection plan, and list the specific items that still need confirmation:

1. Repository/module root directory;
2. Target tool and version;
3. Project configuration files;
4. The authoritative command in CI;
5. Whether auto-fixes are allowed.

FAQ

Q1: If the tool is not installed, can we conclude the code is fine? No. The status must be UNVERIFIED。

Q2: Can ignore or suppression be added automatically? No. An exemption is only allowed when the user explicitly accepts it and the reason is documented.

Q3: Why does it still fail after formatting? The formatter only covers formatting; static rules, configuration, compilation, and tests still need to be handled separately.

Q4: Should generated code be scanned? By default, follow the repository configuration; if there is no rule, exclude generated/vendor first, then explain to the user.

Q5: How can I avoid changing too much at once? Fix in batches by failure category and file first, and re-run the original command and review the diff for each batch.

Q6: If it passes locally, can I say CI will pass? No. You also need to align CI's version, environment variables, operating system, and command scope.

Load resources on demand

• When encountering exit codes, failure classifications, or exemption decisions, read references/rules/gate-rules.md。
• When you need to verify the language's registry, toolchain, and project configuration, read references/tooling/toolchain.md。
• When you need copyable task examples, read by scenario examples/, and there is no need to load them all at once.