Agent Skills › nixopus/nixopus › java-deploy

java-deploy

GitHub

用于构建和部署Java应用，支持Maven/Gradle及Spring Boot等框架。涵盖版本检测、构建命令、端口识别、Dockerfile生成及缓存优化，适用于Java项目的发布流程。

api/skills/java-deploy/SKILL.md nixopus/nixopus

Trigger Scenarios

需要构建或部署Java项目时检测到pom.xml或build.gradle文件

Install

npx skills add nixopus/nixopus --skill java-deploy -g -y

More Options

Non-standard path

npx skills add https://github.com/nixopus/nixopus/tree/master/api/skills/java-deploy -g -y

Use without installing

npx skills use nixopus/nixopus@java-deploy

指定 Agent (Claude Code)

npx skills add nixopus/nixopus --skill java-deploy -a claude-code -g -y

安装 repo 全部 skill

npx skills add nixopus/nixopus --all -g -y

预览 repo 内 skill

npx skills add nixopus/nixopus --list

SKILL.md

Frontmatter

{
    "name": "java-deploy",
    "metadata": {
        "version": "1.0"
    },
    "description": "Build and deploy Java applications — Maven, Gradle, Spring Boot, version detection, and Dockerfile patterns. Use when deploying a Java project, or when pom.xml or build.gradle is detected."
}

Java Deployment

Detection

Project is Java if:

Maven: pom.xml exists at the root
Gradle: gradlew or build.gradle / build.gradle.kts exists at the root

Versions

Java / JDK

pom.xml → maven.compiler.source or maven.compiler.target
build.gradle → sourceCompatibility or JavaLanguageVersion
.sdkmanrc or .java-version file
Defaults to 21

Gradle

Read from gradle/wrapper/gradle-wrapper.properties → distributionUrl.

Build

Maven

mvn -B package -DskipTests
Output: target/<artifact-id>-<version>.jar
Spring Boot: target/*.jar (fat JAR)
Offline deps: mvn -B dependency:go-offline for layer caching

Gradle

./gradlew build -x test (prefer wrapper when gradlew exists)
Use --no-daemon in Docker
Output: build/libs/<name>-<version>.jar
Spring Boot: build/libs/*.jar (fat JAR)
Warm deps: ./gradlew dependencies --no-daemon for layer caching

Start Command

java -jar <jar-file>
Spring Boot: java -jar app.jar

Port Detection

server.port in application.properties or application.yml
PORT or SERVER_PORT environment
Spring Boot default: 8080
Default: 8080

Framework Detection

Dependency / config	Framework
`spring-boot-starter-web`	Spring Boot
`spring-boot-starter-webflux`	Spring Boot (reactive)
`quarkus`	Quarkus
`micronaut`	Micronaut
`jakarta.servlet`	Jakarta EE / Servlet

Spring Boot

Fat JAR includes embedded Tomcat
Config: application.properties, application.yml, application-*.yml

Install Stage Optimization

Maven: pom.xml, pom.xml children (multi-module)
Gradle: build.gradle, build.gradle.kts, settings.gradle, gradlew, gradle/wrapper/*
Then: src/

Caching

Use BuildKit cache mounts:

Gradle:

RUN --mount=type=cache,target=/root/.gradle \
    ./gradlew build -x test --no-daemon

Maven:

RUN --mount=type=cache,target=/root/.m2/repository \
    mvn -B package -DskipTests

Base Images

Stage	Image
Build (Maven)	`eclipse-temurin:21-jdk-alpine` or `maven:3-eclipse-temurin-21`
Build (Gradle)	`eclipse-temurin:21-jdk-alpine`
Runtime	`eclipse-temurin:21-jre-alpine` or `amazoncorretto:21-alpine`

Use JRE (not JDK) for runtime.

Dockerfile Patterns

Maven + Spring Boot

FROM eclipse-temurin:21-jdk-alpine AS build
WORKDIR /app
COPY pom.xml ./
RUN mvn -B dependency:go-offline
COPY src ./src
RUN mvn -B package -DskipTests

FROM eclipse-temurin:21-jre-alpine
WORKDIR /app
COPY --from=build /app/target/*.jar app.jar
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]

Gradle + Spring Boot

FROM eclipse-temurin:21-jdk-alpine AS build
WORKDIR /app
COPY gradlew ./
COPY gradle gradle
COPY build.gradle settings.gradle ./
RUN ./gradlew dependencies --no-daemon
COPY src ./src
RUN ./gradlew build -x test --no-daemon

FROM eclipse-temurin:21-jre-alpine
WORKDIR /app
COPY --from=build /app/build/libs/*.jar app.jar
EXPOSE 8080
ENTRYPOINT ["java", "-jar", "app.jar"]

Simple Maven (no Spring Boot)

FROM eclipse-temurin:21-jdk-alpine AS build
WORKDIR /app
COPY pom.xml ./
RUN mvn -B dependency:go-offline
COPY src ./src
RUN mvn -B package -DskipTests

FROM eclipse-temurin:21-jre-alpine
WORKDIR /app
COPY --from=build /app/target/*.jar app.jar
EXPOSE 8080
CMD ["java", "-jar", "app.jar"]

Gotchas

Gradle wrapper gradlew must have execute permission — add RUN chmod +x gradlew in the Dockerfile if builds fail with permission denied
--no-daemon is essential for Gradle in Docker — the daemon persists between builds, wastes memory, and can hang
Spring Boot fat JAR glob target/*.jar may match multiple JARs (sources, javadoc) — use maven-jar-plugin with a fixed finalName or be specific with the path
Use JRE (not JDK) for the runtime stage — JDK adds ~200MB of unnecessary build tools
JAVA_TOOL_OPTIONS affects all stages including runtime — unset it after the build stage if used for build-only JVM flags