菜单
Detect a Maven/Gradle project's REAL current Java level (by its declared bytecode target, not the build toolchain) and dispatch to the matching one-LTS bump hop (8->11, 11->17, 17->21, 21->25). Use as the entry point: it decides the hop and whether the project should be bumped at all.
用 Codex 或 Claude 帮你安装 复制这段 Prompt，粘贴到 Codex、Claude 或其他助手里，让它检查 Skill 页面并帮你完成安装。
基于 SOC 职业分类
| name | detect-java-version |
| description | Detect a Maven/Gradle project's REAL current Java level (by its declared bytecode target, not the build toolchain) and dispatch to the matching one-LTS bump hop (8->11, 11->17, 17->21, 21->25). Use as the entry point: it decides the hop and whether the project should be bumped at all. |
A project's build toolchain (the JDK Gradle/Maven builds with) is NOT its bytecode target (the Java version it emits). Many libraries deliberately build with a new JDK but pin old bytecode for consumer reach (OpenTelemetry instrumentation, Gradle plugins, SDKs). Dispatching on the toolchain mislabels these and tries an impossible/harmful bump. So always detect the real level first.
detect_java_version.sh <repo> <sha> -> JSON. It reads, across ALL modules, the declared bytecode target
(precedence: options.release / <maven.compiler.release> > source/targetCompatibility / <source> /
jvmTarget > the toolchain languageVersion), and reports:
detected, the MIN bytecode target across modules (the true current Java level).low_target, TRUE if a bytecode target is pinned BELOW the toolchain, OR modules target different levels
(multi-target), OR a java-gradle-plugin is applied. These are deliberate-low-target projects.bumpable, TRUE only if a clean single target below the latest LTS AND not low_target.hop_to, the next LTS above detected.bumpable: false -> NOT_A_BUMP (record + stop). Bumping its bytecode would regress its consumers; it
is not a migration target. Do NOT score it as a failed bump.detected's LTS bracket: 8->11, 11->17, 17->21, or 21->25
(build JDKs are the LTS rungs; a non-LTS detected level brackets down, e.g. 14 -> the 11->17 hop).The orchestrator run_repo.sh <repo> <sha> <slug> does both: detect -> NOT_A_BUMP or dispatch.
Discover and expand the training dataset of real GitHub repos used to evaluate and harden the bump-java-version skill. Find FRESH unique Maven or Gradle projects that declare a given Java LTS (8/11/17/21), dedupe them against the corpus we already have, and validate which actually compile into baselines. Use when growing the corpus, filling a Java-version gap (e.g. need more J17/J21 baselines), or adding a build tool (Gradle). Harness tooling — NOT the portable bump-java-version skill.
Migrate a Maven or Gradle project one Java LTS step from Java 11 to Java 17: it must compile under JDK 17, conserve every previously-passing test, and raise the effective compiler target to 17, using only standard tools (JDKs, Maven or Gradle, OpenRewrite recipes from Maven Central; no project-specific scripts). Use for an 11→17 Java LTS bump.
Migrate a Maven or Gradle project one Java LTS step from Java 17 to Java 21: it must compile under JDK 21, conserve every previously-passing test, and raise the effective compiler target to 21, using only standard tools (JDKs, Maven or Gradle, OpenRewrite recipes from Maven Central; no project-specific scripts). Use for a 17→21 Java LTS bump.
Migrate a Maven or Gradle project one Java LTS step from Java 21 to Java 25: it must compile under JDK 25, conserve every previously-passing test, and raise the effective compiler target to 25, using only standard tools (JDKs, Maven or Gradle, OpenRewrite recipes from Maven Central; no project-specific scripts). Use for a 21→25 Java LTS bump.
Migrate a Maven or Gradle project one Java LTS step from Java 8 to Java 11: it must compile under JDK 11, conserve every previously-passing test, and raise the effective compiler target to 11, using only standard tools (JDKs, Maven or Gradle, OpenRewrite recipes from Maven Central; no project-specific scripts). Use for an 8→11 Java LTS bump.
Migrate a Maven or Gradle project from one Java LTS to the next (8->11, 11->17, 17->21, 21->25) so it still compiles under the new JDK and previously-passing tests still pass — via OpenRewrite recipes, using only standard tools (JDKs, Maven or Gradle, and OpenRewrite recipes from Maven Central; no project-specific scripts). Use when upgrading or bumping the Java version of a Maven or Gradle project, modernizing to a newer JDK or LTS, or performing the Spring Boot 1->2 / 2->3 and javax->jakarta migration that a Java upgrade requires.