当我用Jenkins用Maven构建Spring Boot应用程序并执行JAR文件时，找不到类定义？

Question

• I suppose it can not find the class path. Because I can run the jar file JAR in a local environment of the IDE ( IntelliJ IDEA ). I use the code snippets below to print class path information.

  ClassLoader cl = ClassLoader.getSystemClassLoader(); URL[] urls = ((URLClassLoader)cl).getURLs(); if (urls == null || urls.length == 0) { System.out.println("Is this a empty classpath?"); } for(URL url: urls){ System.out.println("This is classpath:" + url.getFile()); }

When I click the Run button in IntelliJ IDEA, it can list all dependency class, such as, It's right.

This is classpath:/Users/admin/.m2/repository/org/springframework/boot/spring-boot-starter/1.5.10.RELEASE/spring-boot-starter-1.5.10.RELEASE.jar This is classpath:/Users/admin/.m2/repository/org/springframework/boot/spring-boot/1.5.10.RELEASE/spring-boot-1.5.10.RELEASE.jar

But when I run it locally, it just prints one message. It's just my JAR package directory. It's wrong.

• I read the documentation about the manifest file. It does contain a JAR file. Its location is main/resources directory. But it has no directory prefix. It's generated by IntelliJ IDEA automatically. And I unzip the JAR package to check the META-INF/MANIFEST.MF file. It also contains the Main-Class key.

  Manifest-Version: 1.0 Class-Path: spring-data-rest-core-2.6.10.RELEASE.jar mapstruct-1.1.0.F inal.jar logback-core-1.1.11.jar javax.transaction-api-1.2.jar

• I check my pom.xml file. It has the maven-jar-plugin configuration. I comment out classpathPrefix and classpathLayoutType. I consider it seems like no use.

  <plugin> <!-- Build an executable JAR --> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-jar-plugin</artifactId> <version>3.1.0</version> <configuration> <archive> <manifest> <addClasspath>true</addClasspath> <!--<classpathPrefix>lib/</classpathPrefix>--> <mainClass>com.hzlf.LetFunGoApplication</mainClass> <!--<classpathPrefix>/Users/admin/.m2/repository</classpathPrefix>--> <!--<classpathLayoutType>repository</classpathLayoutType>--> </manifest> </archive> </configuration> </plugin>

  I doubt it is a wrong configuration for this maven-jar-plugin. Its classPathPrefix is a relative path. How can I write it correctly about repository? My local Maven home directory is /Users/admin/.m2/ . In my Docker container, it's /root/.m2 .

• I use a Jenkinsfile to pull an image from Docker hub in my project. Here is my Jenkinsfile configuration. In the deliver.sh file, just to run the JAR package.

  pipeline { agent { docker { image 'maven:3-alpine' args '-v $HOME/.m2:/root/.m2' } } stages { stage('build') { steps { sh 'mvn --version' sh 'mvn clean package' } } stage('Test') { steps { sh 'mvn test' } post { always { junit 'target/surefire-reports/*.xml' } } } stage('Deliver') { steps { sh './jenkins/scripts/deliver.sh' } } } } This is error information. It confused me a long time.

  Error: A JNI error has occurred, please check your installation and try again Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/boot/autoconfigure/web/HttpMessageConverters at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) at java.lang.Class.privateGetMethodRecursive(Class.java:3048) at java.lang.Class.getMethod0(Class.java:3018) at java.lang.Class.getMethod(Class.java:1784) at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526) Caused by: java.lang.ClassNotFoundException: org.springframework.boot.autoconfigure.web.HttpMessageConverters at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 7 more [Pipeline] } [Pipe line] // stage [Pipeline] } $ docker stop --time=1 693b10dd721c5780761b00eef880b793f6fa2e94afb77e9ffbac9474360f8a5f $ docker rm -f 693b10dd721c5780761b00eef880b793f6fa2e94afb77e9ffbac9474360f8a5f [Pipeline] // withDockerContainer [Pipeline] } [Pipeline] // withEnv [Pipeline] } [Pipeline] // node [Pipeline] End of Pipeline ERROR: script returned exit code 1 Finished: FAILURE

  1 : https://docs.oracle.com/javase/tutorial/deployment/jar/manifestindex.html [2]: https://i.stack.imgur.com/CaMnb.png [3]: https://i.stack.imgur.com/kbVvJ.png

Answer 1

I resolve it by modifying my deliver.sh. I don't know the real reason, but it works. I just delete Test stage and Deliver stage. I guess it results from the 'post' option in deliver.sh.

pipeline {
    agent {
        docker {
            image 'maven:3-alpine'
            args '-v $HOME/.m2:/root/.m2'
        }
    }
    stages {
        stage('build') {
            steps {
                sh 'mvn --version'
                sh 'mvn clean package'
            }
        }
    }
}