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我想在 SCP Neo 的现有 java 项目中使用 S/4 HANA SDK。有人建议我生成一个新项目，然后将我现有的代码移动到应用程序下生成的项目中。我使用 S/4 HANA SDK 教程步骤 2 中指定的架构师类型生成了一个新项目，并将现有代码复制到应用程序模块。当我尝试在 SCP Neo 中部署我的应用程序并尝试启动它时。它没有启动，在 SCP 日志中，我看到了以下错误。请指教如何解决？（我现有的也使用记录器）。

此致

弗雷德·Z

24 Feb 23:14:15 UTC - org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/s4scheduler-application]
2019 02 24 23:14:15#+00#ERROR#org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/s4scheduler-application]##anonymous#localhost-startStop-1#na#ogfigrvps3#s4schedulerapplication#web##na#na#na#na#Error configuring application listener of class [com.sap.cloud.sdk.s4hana.connectivity.ErpDestination] java.lang.LinkageError: loader constraint violation: when resolving method "org.slf4j.impl.StaticLoggerBinder.getLoggerFactory()Lorg/slf4j/ILoggerFactory;" the class loader "<unnamed>" (instance of org.apache.catalina.loader.ParallelWebappClassLoader@3b3235ca, child of java.net.URLClassLoader@61baa894) of the current class, org/slf4j/LoggerFactory, and the class loader "System" (instance of sun.misc.Launcher$AppClassLoader@277050dc, child of sun.misc.Launcher$ExtClassLoader@2b71fc7e, urls: 'file:/usr/lib/jvm/sapjvm_8/sapjvm_8/lib/jvmx.jar', 'file:/usr/lib/jvm/sapjvm_8/sapjvm_8/lib/tools.jar', 'file:/usr/sap/ljs/bin/jul-to-slf4j.jar', 'file:/usr/sap/ljs/bin/slf4j-api.jar', 'file:/usr/sap/ljs/bin/logback-classic.jar', 'file:/usr/sap/ljs/bin/logback-core.jar', 'file:/usr/sap/ljs/bin/logback-config/', 'file:/usr/sap/ljs/bin/com.sap.core.js.logging.jar', 'file:/usr/sap/ljs/bin/bootstrap.jar', 'file:/usr/sap/ljs/bin/tomcat-juli.jar') for the method's defining class, org/slf4j/impl/StaticLoggerBinder, have different Class objects for the type org/slf4j/ILoggerFactory used in the signature
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:418)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
at com.sap.cloud.sdk.cloudplatform.logging.CloudLoggerFactory.<clinit>(CloudLoggerFactory.java:21)
at com.sap.cloud.sdk.cloudplatform.connectivity.DestinationDeclarator.<clinit>(DestinationDeclarator.java:29)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:151)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4714)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5256)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:754)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:985)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1857)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:836)
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1 回答 1

1

解决方案

根据是否some.other.group.id:some-other-artifact-id在您的控制之下，您有两个选项，选项 1 是首选。

  1. 如果您可以更改 的依赖关系some-other-artifact-id，请删除任何具有 和 范围的具体记录器实现compile，provided并将它们替换为slf4j-api. 如有必要，例如对于测试，您可以在范围test或runtime. 这通常是库的最佳实践，因为库无法知道在使用该库构建的实际应用程序中使用了哪个实际记录器。

  2. 如果您无法直接控制依赖项，some-other-artifact-id则可以通过将以下内容添加到dependencies您的块中来删除依赖项pom.xml：

    <dependency>
    <groupId>some.other.group.id</groupId>
    <artifactId>some-other-artifact-id</artifactId>
    <exclusions>
        <exclusion>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
        </exclusion>
    </exclusions>
</dependency>

背景

依赖关系树的重要部分提取如下：

[INFO] --- maven-dependency-plugin:3.1.1:tree (default-cli) @ some-application ---
[INFO] some.group.id:some-artifact-id:jar:1.0
...
[INFO] +- org.slf4j:slf4j-api:jar:1.7.25:compile
[INFO] +- org.slf4j:jcl-over-slf4j:jar:1.7.25:runtime
[INFO] +- some.other.group.id:some-other-artifact-id:jar:1.0:compile
...
[INFO] |  +- org.apache.httpcomponents:httpclient:jar:4.5.6:compile
[INFO] |  |  \- commons-logging:commons-logging:jar:1.2:compile
...

你对你的类路径jcl-over-slf4j有commons-logging依赖。由于第一个是第二个的“插入式”替换，因此您现在基本上对相同的类有两组实现，这会导致运行时错误。

进一步阅读

于 2019-03-11T07:54:42.187 回答