在类路径上找到多个绑定，并在类路径上检测到log4j-over-slf4j.jar和slf4j-log4j12.jar

Question

我正在使用Gradle作为构建工具，在部署过程中，我遇到了下面提到的一些问题。

Gradle构建任务没有问题，但是当我将其部署在tomcat8上时，它显示以下错误。

build.gradle依赖项文件如下：

dependencies {

    testCompile group: 'junit', name: 'junit', version: '4.12'

    compile group: 'javax.servlet', name: 'javax.servlet-api', version: '3.1.0'
    compile group: 'org.json', name: 'json', version: '20090211'

    // Apache Kafka Dependencies
    compile group: 'org.apache.kafka', name: 'kafka-clients', version: '2.0.0'
    compile group: 'org.apache.kafka', name: 'connect-json', version: '2.0.0'

    // Office365 authentication Dependencies
    compile group: 'com.microsoft.azure', name: 'adal4j', version: '1.6.0'
    runtime group: 'com.nimbusds', name: 'oauth2-oidc-sdk', version: '5.24.1'

    // Apache Hadoop HDFS Dependencies
    compile group: 'org.apache.hadoop', name: 'hadoop-hdfs', version: '2.9.1'
    compile group: 'org.apache.hadoop', name: 'hadoop-hdfs-client', version: '2.9.1'
    compile group: 'org.apache.hadoop', name: 'hadoop-common', version: '2.9.1'
    compile group: 'org.apache.hive', name: 'hive-jdbc', version: '2.3.3'

    // Spring Dependencies
    compile group: 'opensymphony', name: 'sitemesh', version: '2.4.2'
    compile group: 'org.springframework', name: 'spring-webmvc', version: '4.3.14.RELEASE'
    compile group: 'org.springframework', name: 'spring-tx', version: '4.3.14.RELEASE'

    // Mysql Connector Dependency
    compile group: 'mysql', name: 'mysql-connector-java', version: '6.0.6'

    // Apache Spark Dependencies
    compile group: 'com.databricks', name: 'spark-csv_2.11', version: '1.5.0'
    compile group: 'org.apache.spark', name: 'spark-sql_2.11', version: '2.3.0'
    compile group: 'org.apache.spark', name: 'spark-core_2.11', version: '2.3.0'
    compile group: 'com.fasterxml.jackson.module', name: 'jackson-module-scala_2.11', version: '2.8.8'

    // Apache Storm & Apache Kafka Consumer Dependencies
    compile group: 'org.apache.storm', name: 'storm-core', version: '1.2.0'
    compile group: 'org.apache.storm', name: 'storm-kafka', version: '1.2.0'
    compile group: 'org.apache.kafka', name: 'kafka_2.10', version: '0.9.0.1'

    // Elasticsearch Dependencies
    compile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version: '6.5.2'
    compile group: 'org.elasticsearch', name: 'elasticsearch', version: '6.5.2'
    //compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.11.1'
    //compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.11.1'
    //compile group: 'org.slf4j', name: 'slf4j-log4j12'
}   

错误信息：

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/sagarjoshi/opt/tomcat-analytics/apache-tomcat-8.0.53/webapps/analytics/WEB-INF/lib/slf4j-log4j12-1.7.25.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/sagarjoshi/opt/tomcat-analytics/apache-tomcat-8.0.53/webapps/analytics/WEB-INF/lib/log4j-slf4j-impl-2.8.2.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/sagarjoshi/opt/tomcat-analytics/apache-tomcat-8.0.53/webapps/analytics/WEB-INF/lib/logback-classic-1.0.9.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError. 
SLF4J: See also http://www.slf4j.org/codes.html#log4jDelegationLoop for more details.
17-Dec-2018 11:32:29.244 SEVERE [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.startInternal Error during ServletContainerInitializer processing
 javax.servlet.ServletException: Failed to instantiate WebApplicationInitializer class
    at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:155)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5352)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:755)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:731)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
    at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1730)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:485)
    at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:434)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
    at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
    at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
    at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
    at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
    at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
    at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:357)
    at sun.rmi.transport.Transport$1.run(Transport.java:200)
    at sun.rmi.transport.Transport$1.run(Transport.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
    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:748)

Answer 1

检查您的项目依赖项。 真的需要这么多编译依赖项吗？ 检查所有API并使用匹配范围。 可能runtime通常就足够了。

您的程序对日志API和桥接（log4和slf4j的logback）具有多个定义。 确定要使用哪一个，并相应地声明依赖项。 提供使用的日志记录API的配置。

请参阅slf4j-桥接如何工作。

如果您要标识具有不良瞬时依赖关系的项目，请使用gradle依赖关系树（请参阅gradle-检查依赖关系 ）

gradlew dependencies

可能在分析了依赖关系之后，您可能需要根据运行时环境排除一些依赖关系。 请参阅gradle-管理瞬态依赖项如何执行此操作。