问题描述
我正在尝试将十年前编写的项目移植到Java 11。
经过几天的努力，我陷入了这个错误：
Caused by:
java.util.ServiceConfigurationError: org.apache.juli.logging.Log: org.eclipse.jetty.apache.jsp.JuliLog not a subtype
at java.base/java.util.ServiceLoader.fail(ServiceLoader.java:588)
at java.base/java.util.ServiceLoader$LazyClasspathLookupIterator.hasNextService(ServiceLoader.java:1236)
...
如果我通过其jar -xf和uberjar {rip} grep，我会同时看到JuliLog和juli.logging版本：
rg "JuliLog|juli\.logging"
jar/meta-inf/services/org.apache.juli.logging.Log
1:org.eclipse.jetty.apache.jsp.JuliLog
jar/meta-inf/maven/org.mortbay.jasper/apache-jsp/pom.xml
216: filter:="(osgi.serviceloader=org.apache.juli.logging.Log)";resolution:=optional;cardinality:=multiple,235: org.apache.juli.logging;version="${parsedVersion.majorVersion}.${parsedVersion.minorVersion}.${parsedVersion.incrementalVersion}",jar/meta-inf/maven/org.eclipse.jetty/apache-jsp/pom.xml
28: <Provide-Capability>osgi.serviceloader;osgi.serviceloader=javax.servlet.ServletContainerInitializer,osgi.serviceloader;osgi.serviceloader=org.apache.juli.logging.Log</Provide-Capability>
45: <exclude>meta-inf/services/org.apache.juli.logging.Log</exclude>
由此，对于同一groupId工件，我看到了不同的apache-jsp，但是事实证明一个是另一个的依赖项。
mvn dependency:tree | grep -i apache-jsp -C5
...
[INFO] +- org.eclipse.jetty:jetty-servlet:jar:9.4.31.v20200723:compile
[INFO] | \- org.eclipse.jetty:jetty-security:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:jetty-webapp:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:jetty-xml:jar:9.4.31.v20200723:compile
[INFO] | \- org.eclipse.jetty:jetty-util:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:apache-jsp:jar:9.4.31.v20200723:compile
[INFO] | +- org.eclipse.jetty.toolchain:jetty-schemas:jar:3.1.2:compile
[INFO] | +- org.mortbay.jasper:apache-jsp:jar:8.5.54:compile
[INFO] | | +- org.mortbay.jasper:apache-el:jar:8.5.54:compile
...
在pom中，我仅指定月食apache-jsp，这是为了防止与缺乏JSP支持（2020-09-15 10:08:50.037:INFO:oejw.StandardDescriptorProcessor:main: NO JSP Support for /my-application,did not find org.eclipse.jetty.jsp.JettyJspServlet）有关的错误
StackOverflow上的其他问题与对tomcat（either explicitly或via Spring）或gwt的依赖关系有关。我什么都没有，但是如果重要的话，我确实对其他码头缸有依赖性：
mvn dependency:tree | grep -i tomcat -C5
# no results
mvn dependency:tree | grep -i gwt -C5
# no results
mvn dependency:tree | grep -i jetty -C5
...
[INFO] +- org.eclipse.jetty:jetty-server:jar:9.4.31.v20200723:compile
[INFO] | +- org.eclipse.jetty:jetty-http:jar:9.4.31.v20200723:compile
[INFO] | \- org.eclipse.jetty:jetty-io:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:jetty-servlet:jar:9.4.31.v20200723:compile
[INFO] | \- org.eclipse.jetty:jetty-security:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:jetty-webapp:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:jetty-xml:jar:9.4.31.v20200723:compile
[INFO] | \- org.eclipse.jetty:jetty-util:jar:9.4.31.v20200723:compile
[INFO] +- org.eclipse.jetty:apache-jsp:jar:9.4.31.v20200723:compile
[INFO] | +- org.eclipse.jetty.toolchain:jetty-schemas:jar:3.1.2:compile
[INFO] | +- org.mortbay.jasper:apache-jsp:jar:8.5.54:compile
[INFO] | | +- org.mortbay.jasper:apache-el:jar:8.5.54:compile
[INFO] | | \- org.eclipse.jdt:ecj:jar:3.19.0:compile
[INFO] | \- org.eclipse.jetty:jetty-annotations:jar:9.4.31.v20200723:compile
[INFO] | +- org.eclipse.jetty:jetty-plus:jar:9.4.31.v20200723:compile
[INFO] | | \- org.eclipse.jetty:jetty-jndi:jar:9.4.31.v20200723:compile
...
其他解决方案被明确排除在项目中apache-jsp之外，但这正是提供我的JSP支持的原因，因此对我来说不起作用。
我以为我可以使用<exclusion>，但是mvn dependency:tree | grep -i juli -C5不会返回任何结果，所以我不确定如何在此处添加一个。
更新：多亏了Joakim，我能够<exclusion>整理一堆重复的类，从而大大清理了我的罐子，以至于我唯一的重复是about.html文件以及jmockit和junit之间的一些重叠：
mvn org.basepom.maven:duplicate-finder-maven-plugin:check
...
[INFO] Checking compile classpath
[INFO] Checking runtime classpath
[INFO] Checking test classpath
[WARNING] Found duplicate and different resources in [org.eclipse.jdt:ecj:3.19.0,org.eclipse.jetty.toolchain:jetty-schemas:3.1.2,org.eclipse.jetty:apache-jsp:9.4.31.v20200723,org.eclipse.jetty:jetty-annotations:9.4.31.v20200723,org.eclipse.jetty:jetty-http:9.4.31.v20200723,org.eclipse.jetty:jetty-io:9.4.31.v20200723,org.eclipse.jetty:jetty-jndi:9.4.31.v20200723,org.eclipse.jetty:jetty-plus:9.4.31.v20200723,org.eclipse.jetty:jetty-security:9.4.31.v20200723,org.eclipse.jetty:jetty-server:9.4.31.v20200723,org.eclipse.jetty:jetty-servlet:9.4.31.v20200723,org.eclipse.jetty:jetty-util:9.4.31.v20200723,org.eclipse.jetty:jetty-webapp:9.4.31.v20200723,org.eclipse.jetty:jetty-xml:9.4.31.v20200723,org.eclipse.jgit:org.eclipse.jgit:1.0.0.201106090707-r]:
[WARNING] about.html
[WARNING] Found duplicate and different resources in [org.eclipse.jdt:ecj:3.19.0,org.eclipse.jgit:org.eclipse.jgit:1.0.0.201106090707-r]:
[WARNING] about.html
[WARNING] Found duplicate and different classes in [com.googlecode.jmockit:jmockit:1.7,junit:junit:4.11]:
[WARNING] junit.framework.TestResult
[WARNING] org.junit.runner.Runner
[WARNING] Found duplicate and different resources in [org.eclipse.jdt:ecj:3.19.0,org.eclipse.jgit:org.eclipse.jgit:1.0.0.201106090707-r]:
[WARNING] about.html
...
不幸的是，这不能解决我的问题。
解决方法
您在类路径中和/或在多个ClassLoader位置中有多个org.apache.juli.logging.Log的副本的可能性很高，这令人感到困惑。
重要提示：您确实应该解决重复的类问题。
由于您正在使用Maven，请使用重复的类查找器插件之一。
请参阅：Find duplicated classes in classpath
选项B，一旦您解决了所有重复的类问题，将对nolog使用apache-jsp分类的工件。
https://search.maven.org/artifact/org.eclipse.jetty/apache-jsp/9.4.31.v20200723/jar
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>apache-jsp</artifactId>
<version>9.4.31.v20200723</version>
<classifier>nolog</classifier>
</dependency>