我试图在我的NiFi安装中安装自定义NAR控制器服务包,但在启动过程中出现此错误。即使它作为依赖项包含在内,它的行为似乎也无法从RecordReaderFactory中找到nifi-record-serialization-service-api类:

<dependency>
   <groupId>org.apache.nifi</groupId>
   <artifactId>nifi-record-serialization-service-api</artifactId>
   <version>1.9.0</version>
</dependency>


这是项目:
https://github.com/adamfisher/nifi-zonefile-record-serialization-service

运行maven install会成功构建NAR。只是当我启动NiFi时,会出现此错误。我很确定这是Maven POM配置问题。我只是不使用Java太多,希望有人可以阐明为什么它找不到所需的依赖类?

nifi-app.log:

2019-03-02 15:22:15,245 INFO [main] org.apache.nifi.web.server.JettyServer Loading WAR: D:\nifi\NIFI-1~2.0\.\work\nar\framework\nifi-framework-nar-1.9.0.nar-unpacked\NAR-INF\bundled-dependencies\nifi-web-error-1.9.0.war with context path set to /
2019-03-02 15:22:15,261 INFO [main] org.apache.nifi.web.server.JettyServer Running in HTTP mode; host headers not restricted
2019-03-02 15:22:16,386 ERROR [main] org.apache.nifi.NiFi Failure to launch NiFi due to java.lang.NoClassDefFoundError: org/apache/nifi/serialization/RecordReaderFactory
java.lang.NoClassDefFoundError: org/apache/nifi/serialization/RecordReaderFactory
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:370)
    at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
    at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
    at org.apache.nifi.nar.StandardExtensionDiscoveringManager.loadExtensions(StandardExtensionDiscoveringManager.java:152)
    at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:127)
    at org.apache.nifi.nar.StandardExtensionDiscoveringManager.discoverExtensions(StandardExtensionDiscoveringManager.java:113)
    at org.apache.nifi.web.server.JettyServer.start(JettyServer.java:925)
    at org.apache.nifi.NiFi.<init>(NiFi.java:158)
    at org.apache.nifi.NiFi.<init>(NiFi.java:72)
    at org.apache.nifi.NiFi.main(NiFi.java:297)
Caused by: java.lang.ClassNotFoundException: org.apache.nifi.serialization.RecordReaderFactory
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 23 common frames omitted
2019-03-02 15:22:16,387 INFO [Thread-1] org.apache.nifi.NiFi Initiating shutdown of Jetty web server...
2019-03-02 15:22:16,387 INFO [Thread-1] org.apache.nifi.NiFi Jetty web server shutdown completed (nicely or otherwise).

最佳答案

NAR依赖项在运行时用于创建父类加载器链。所以在你的例子中

nifi-zonefile-record-serialization-service-nar->(取决于)

nifi-zonefile-record-serialization-service-api-nar->(取决于)

nifi-标准服务-api-nar

在运行的应用程序中,当从服务NAR实例化记录读取器的实例时,它需要加载来自服务API的实现的接口NAR,然后需要加载来自标准服务API的RecordReader接口NAR。

关于java - 启动期间的Apache NiFi自定义NAR NoClassDefFoundError,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/54963492/

10-09 09:51