tomcat - Grails war 无法部署 java.lang.NoClassDefFoundError 和 SLF4J : Class path contains multiple SLF4J bindings

Question

当我使用 grails run-app 时，我的应用程序工作正常，但是当尝试使用带有 run-war 的 war 文件运行时，我收到以下错误:

我已经在堆栈上尝试了这里提出的一些解决方案，但没有一个解决了问题。

跟踪中显示的包/类来 self 的一个域类:

nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf

gneellaan = package 和 Ecf = domain class

|Running Grails application
Error |
SLF4J: Class path contains multiple SLF4J bindings.
Error |
SLF4J: Found binding in [jar:file:/C:/grails-2.4.2/dist/grails-plugin-log4j-2.4.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
Error |
SLF4J: Found binding in [jar:file:/C:/Grails/gneellaan/target/work/tomcat/webapps/gneellaan/WEB-INF/lib/grails-plugin-log4j-2.4.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
Error |
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Error |
SLF4J: Actual binding is of type [org.slf4j.impl.GrailsSlf4jLoggerFactory]
2014-10-23 14:28:08,255 [localhost-startStop-1] ERROR context.ContextLoader  - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.lang.Class.forName(Class.java:340)
    ... 4 more
Caused by: java.lang.ClassNotFoundException: gneellaan.Ecf
    ... 5 more
2014-10-23 14:28:08,257 [localhost-startStop-1] ERROR context.GrailsContextLoaderListener  - Error initializing the application: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.lang.Class.forName(Class.java:340)
    ... 4 more
Caused by: java.lang.ClassNotFoundException: gneellaan.Ecf
    ... 5 more
2014-10-23 14:28:08,258 [localhost-startStop-1] ERROR context.GrailsContextLoaderListener  - Error initializing Grails: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.lang.Class.forName(Class.java:340)
    ... 4 more
Caused by: java.lang.ClassNotFoundException: gneellaan.Ecf
    ... 5 more
Exception sending context initialized event to listener instance of class org.codehaus.groovy.grails.web.context.GrailsContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'grailsApplication' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NoClassDefFoundError: gneellaan/Ecf
    at java.lang.Class.forName(Class.java:340)
    ... 4 more
Caused by: java.lang.ClassNotFoundException: gneellaan.Ecf
    ... 5 more
Error listenerStart
Context [/gneellaan] startup failed due to previous errors
The web application [/gneellaan] registered the JDBC driver [org.h2.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
The web application [/gneellaan] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
The web application [/gneellaan] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
|Server running. Browse to http://localhost:9091/gneellaan
|Server running. Browse to http://localhost:9091/gneellaan

Answer 1

正确 - 这是一个类路径问题，Slf4j 消息是可忽略的警告。 java.lang.ClassNotFoundException 和 java.lang.NoClassDefFoundError 之间有很大的区别。 ClassNotFoundException 本身很简单 - 类路径中没有包含该类或资源的 jar 文件或目录。修复类路径，或向其中添加缺少的库，然后继续。

但是 NoClassDefFoundError(将导致 ClassNotFoundException)更难修复。它表示找到了命名的类，但是在加载它时，它没有满足依赖关系。这个在使用Grails、Maven、Gradle等集成依赖管理的时候应该是比较少见的，判断你的依赖的依赖是什么，并包含进去。但是，当我们将查找配置为不通过依赖关系图递归，或者排除一个或多个我们认为可以安全排除的 jar 时，就会发生这种情况。

我猜 gneellaan.Ecf 是您的类(class) - 在 Google 中恰好有 1 个结果，就是这个问题(从技术上讲，这是两个词，但我仍然称其为 Googlewhack ).如果它是第 3 方库，您可以使用像 http://mvnrepository.com/ 这样的网站确定依赖关系(例如 http://mvnrepository.com/artifact/io.hawt/hawtio-util/1.4.27 )。但是你有源头，所以不难找到原因。如果该类中发生了很多事情，请尝试注释掉你能注释掉的内容，确保所有内容仍然可以编译，但删除你能删除的内容。