部署SpringBoot镜像至AWS集群时遇ClassNotFoundException问题求助

问题描述 #

开发SpringBoot应用，已通过Docker完成容器化并推送至AWS ECR，但部署镜像创建AWS集群服务运行任务时出现错误，日志如下：

Caused by: java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/boot/SpringApplication
at com.portfolio.quizapp.QuizappApplication.main(QuizappApplication.java:10)

已尝试调整依赖、更换版本及添加其他依赖，均未解决问题，当前pom.xml内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.portfolio</groupId>
    <artifactId>quizapp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>quizapp</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
        
    <start-class>com.portfolio.quizapp.QuizappApplication</start-class>
    </properties>
    <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-surefire-plugin -->
<dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.1.2</version>
</dependency>

    </dependencies>

    <build>
        <plugins>
                <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
            <!-- <mainClass>com.portfolio.quizapp.QuizappApplication</mainClass>
            <layout>JAR</layout> -->
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
                <executions>
    <execution>
        <goals>
            <goal>repackage</goal>
        </goals>
    </execution>
</executions>
            </plugin>
        </plugins>
    </build>

</project>

解决方案 #

1. 移除错误的依赖配置 #

pom.xml的<dependencies>节点下包含了maven-surefire-plugin依赖，这是Maven插件，不属于项目依赖，直接删除这段：

<!-- https://mvnrepository.com/artifact/org.apache.maven.plugins/maven-surefire-plugin -->
<dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.1.2</version>
</dependency>

2. 修正spring-boot-maven-plugin配置 #

取消注释插件中的mainClass和layout配置，确保构建出包含所有依赖的可执行JAR：

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <mainClass>com.portfolio.quizapp.QuizappApplication</mainClass>
        <layout>JAR</layout>
        <excludes>
            <exclude>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </exclude>
        </excludes>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
    </executions>
</plugin>

3. 重新构建并推送镜像 #

执行以下命令构建可执行JAR：

mvn clean package

然后重新构建Docker镜像，推送到AWS ECR。

4. 检查Dockerfile正确性 #

确保Dockerfile使用java -jar启动可执行JAR，示例如下：

FROM openjdk:17-jdk-slim
WORKDIR /app
COPY target/quizapp-0.0.1-SNAPSHOT.jar app.jar
ENTRYPOINT ["java","-jar","/app/app.jar"]

内容的提问来源于stack exchange，提问作者Fu Chang