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此版本仍在开发中，尚未视为稳定版。如需最新稳定版本，请使用 Spring Boot 4.0.4！ |
Dockerfiles
虽然只需在 Dockerfile 中添加几行代码，即可将 Spring Boot 的 uber jar 转换为 Docker 镜像，但使用分层功能将生成一个经过优化的镜像。
当你创建一个包含分层索引文件的 jar 时，spring-boot-jarmode-tools jar 会被作为依赖项添加到你的 jar 中。
当该 jar 位于类路径上时，你可以以一种特殊模式启动应用程序，使得引导代码能够运行与你的应用程序完全不同的内容，例如用于提取分层的工具。
你可以通过以下方式以 tools jar 模式启动你的 jar 文件：
$ java -Djarmode=tools -jar my-app.jar这将产生以下输出：
Usage: java -Djarmode=tools -jar my-app.jar Available commands: extract Extract the contents from the jar list-layers List layers from the jar that can be extracted help Help about any command
extract 命令可用于轻松将应用程序拆分为多个层，以便添加到 Dockerfile 中。
以下是使用 Dockerfile 的 jarmode 示例。
# Perform the extraction in a separate builder container
FROM bellsoft/liberica-openjre-debian:25-cds AS builder
WORKDIR /builder
# This points to the built jar file in the target folder
# Adjust this to 'build/libs/*.jar' if you're using Gradle
ARG JAR_FILE=target/*.jar
# Copy the jar file to the working directory and rename it to application.jar
COPY ${JAR_FILE} application.jar
# Extract the jar file using an efficient layout
RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
# This is the runtime container
FROM bellsoft/liberica-openjre-debian:25-cds
WORKDIR /application
# Copy the extracted jar contents from the builder container into the working directory in the runtime container
# Every copy step creates a new docker layer
# This allows docker to only pull the changes it really needs
COPY --from=builder /builder/extracted/dependencies/ ./
COPY --from=builder /builder/extracted/spring-boot-loader/ ./
COPY --from=builder /builder/extracted/snapshot-dependencies/ ./
COPY --from=builder /builder/extracted/application/ ./
# Start the application jar - this is not the uber jar used by the builder
# This jar only contains application code and references to the extracted jar files
# This layout is efficient to start up and AOT cache (and CDS) friendly
ENTRYPOINT ["java", "-jar", "application.jar"]假设上述 Dockerfile 位于当前目录中，您可以使用 docker build . 构建 Docker 镜像，也可以选择性地指定应用程序 JAR 文件的路径，如下例所示：
$ docker build --build-arg JAR_FILE=path/to/myapp.jar .这是一个多阶段的 Dockerfile。
构建阶段（builder stage）会提取后续所需的目录。
每个 COPY 指令都对应于 jarmode 提取的层。
当然，也可以在不使用 Dockerfile 的情况下编写 jarmode。
你可以结合使用 unzip 和 mv 命令将内容移动到正确的层，但 jarmode 简化了这一过程。
此外，jarmode 创建的布局开箱即用地支持 AOT 缓存（以及 CDS）。
AOT 缓存
| 如果使用的是 Java < 24，AOT 缓存不可用。 您必须使用 CDS 替代。 |
如果你想额外启用AOT 缓存，可以使用以下 Dockerfile：
# Perform the extraction in a separate builder container
FROM bellsoft/liberica-openjre-debian:25-cds AS builder
WORKDIR /builder
# This points to the built jar file in the target folder
# Adjust this to 'build/libs/*.jar' if you're using Gradle
ARG JAR_FILE=target/*.jar
# Copy the jar file to the working directory and rename it to application.jar
COPY ${JAR_FILE} application.jar
# Extract the jar file using an efficient layout
RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
# This is the runtime container
FROM bellsoft/liberica-openjre-debian:25-cds
WORKDIR /application
# Copy the extracted jar contents from the builder container into the working directory in the runtime container
# Every copy step creates a new docker layer
# This allows docker to only pull the changes it really needs
COPY --from=builder /builder/extracted/dependencies/ ./
COPY --from=builder /builder/extracted/spring-boot-loader/ ./
COPY --from=builder /builder/extracted/snapshot-dependencies/ ./
COPY --from=builder /builder/extracted/application/ ./
# Execute the AOT cache training run
RUN java -XX:AOTCacheOutput=app.aot -Dspring.context.exit=onRefresh -jar application.jar
# Start the application jar with AOT cache enabled - this is not the uber jar used by the builder
# This jar only contains application code and references to the extracted jar files
# This layout is efficient to start up and AOT cache friendly
ENTRYPOINT ["java", "-XX:AOTCache=app.aot", "-jar", "application.jar"]这与上面的 Dockerfile 基本相同。
作为最后几步，它通过一次训练运行创建 AOT 缓存文件，并将 AOT 缓存参数传递给 java -jar。
CDS
| 如果您使用的是 Java 24 或更高版本，请使用 AOT 缓存代替 CDS。 |
如果你想额外启用CDS，可以使用以下Dockerfile：
# Perform the extraction in a separate builder container
FROM bellsoft/liberica-openjre-debian:25-cds AS builder
WORKDIR /builder
# This points to the built jar file in the target folder
# Adjust this to 'build/libs/*.jar' if you're using Gradle
ARG JAR_FILE=target/*.jar
# Copy the jar file to the working directory and rename it to application.jar
COPY ${JAR_FILE} application.jar
# Extract the jar file using an efficient layout
RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
# This is the runtime container
FROM bellsoft/liberica-openjre-debian:25-cds
WORKDIR /application
# Copy the extracted jar contents from the builder container into the working directory in the runtime container
# Every copy step creates a new docker layer
# This allows docker to only pull the changes it really needs
COPY --from=builder /builder/extracted/dependencies/ ./
COPY --from=builder /builder/extracted/spring-boot-loader/ ./
COPY --from=builder /builder/extracted/snapshot-dependencies/ ./
COPY --from=builder /builder/extracted/application/ ./
# Execute the CDS training run
RUN java -XX:ArchiveClassesAtExit=application.jsa -Dspring.context.exit=onRefresh -jar application.jar
# Start the application jar with CDS enabled - this is not the uber jar used by the builder
# This jar only contains application code and references to the extracted jar files
# This layout is efficient to start up and CDS friendly
ENTRYPOINT ["java", "-XX:SharedArchiveFile=application.jsa", "-jar", "application.jar"]这与上面的 Dockerfile 基本相同。
作为最后几步，它通过一次训练运行创建 CDS 归档，并将 CDS 参数传递给 java -jar。