Docker部署Spring Boot 3应用报错：无法访问jar文件

问题场景 #

在M1 MacBook上部署Spring Boot 3应用到Docker容器，运行容器时出现以下错误：

docker run -p 8080:8080 myapp_backend:0.0.1
Error: Unable to access jarfile /app.jar

相关文件及日志 #

Dockerfile内容 #

FROM maven:3.8.4-openjdk-17 AS build-stage
WORKDIR /app
COPY pom.xml .
RUN mvn dependency:go-offline

COPY ./src ./src
RUN mvn clean install -Dmaven.test.skip=true

# Stage 2
FROM openjdk:17-jdk-slim AS production-stage
WORKDIR /app
COPY --from=build-stage /app/target/*.jar app.jar

EXPOSE 8080

ENTRYPOINT ["java", "-jar", "/app.jar"]

Docker构建日志 #

> docker build -t myapp_backend:0.0.1 .      
[+] Building 3.2s (15/15) FINISHED                                                                                                                   docker:rancher-desktop
 => [internal] load build definition from Dockerfile                                                                                                                   0.0s
 => => transferring dockerfile: 735B                                                                                                                                   0.0s
 => [internal] load .dockerignore                                                                                                                                      0.0s
 => => transferring context: 2B                                                                                                                                        0.0s
 => [internal] load metadata for docker.io/library/openjdk:17-jdk-slim                                                                                                 3.2s
 => [internal] load metadata for docker.io/library/maven:3.8.4-openjdk-17                                                                                              3.2s
 => [build-stage 1/6] FROM docker.io/library/maven:3.8.4-openjdk-17@sha256:7106ce47b5c226ee21bac386cb706ff9f3db7ac2f15e251e3aa491fcbfc30028                            0.0s
 => [production-stage 1/3] FROM docker.io/library/openjdk:17-jdk-slim@sha256:aaa3b3cb27e3e520b8f116863d0580c438ed55ecfa0bc126b41f68c3f62f9774                          0.0s
 => [internal] load build context                                                                                                                                      0.0s
 => => transferring context: 1.64kB                                                                                                                                    0.0s
 => CACHED [production-stage 2/3] WORKDIR /app                                                                                                                         0.0s
 => CACHED [build-stage 2/6] WORKDIR /app                                                                                                                              0.0s
 => CACHED [build-stage 3/6] COPY pom.xml .                                                                                                                            0.0s
 => CACHED [build-stage 4/6] RUN mvn dependency:go-offline                                                                                                             0.0s
 => CACHED [build-stage 5/6] COPY ./src ./src                                                                                                                          0.0s
 => CACHED [build-stage 6/6] RUN mvn clean install -Dmaven.test.skip=true                                                                                              0.0s
 => CACHED [production-stage 3/3] COPY --from=build-stage /app/target/*.jar app.jar                                                                                    0.0s
 => exporting to image                                                                                                                                                 0.0s
 => => exporting layers                                                                                                                                                0.0s
 => => writing image sha256:f5ca156d9ebda2118100dc1d75ec6240f3e9c283686ea51599cad313bf5744c8                                                                           0.0s
 => => naming to docker.io/library/myapp_backend:0.0.1                                                                                                           0.0s

解决方案 #

1. 修正jar文件路径错误 #

Dockerfile中production-stage的工作目录是/app，复制jar时指定的是当前目录的app.jar，因此实际路径为/app/app.jar，但ENTRYPOINT中写的是根目录下的/app.jar，导致找不到文件。修改ENTRYPOINT为以下任意一种：

# 使用相对路径（推荐，基于WORKDIR）
ENTRYPOINT ["java", "-jar", "app.jar"]

# 或者使用完整绝对路径
ENTRYPOINT ["java", "-jar", "/app/app.jar"]

2. 刷新构建缓存，确认jar生成 #

构建日志中所有步骤都显示CACHED，说明缓存未更新，可能Maven构建未实际生成jar文件。执行以下命令重新构建（禁用缓存）：

docker build --no-cache -t myapp_backend:0.0.1 .

同时检查本地项目的target目录是否存在生成的jar文件，确认mvn clean install -Dmaven.test.skip=true命令执行成功。

3. M1架构适配（可选） #

M1是ARM架构，若使用的基础镜像是AMD64架构，可能存在兼容性问题。可以在Dockerfile开头指定平台：

FROM --platform=linux/arm64 maven:3.8.4-openjdk-17 AS build-stage
FROM --platform=linux/arm64 openjdk:17-jdk-slim AS production-stage

或者构建时指定平台参数：

docker build --platform=linux/arm64 -t myapp_backend:0.0.1 .

内容的提问来源于stack exchange，提问作者demiglace