[LOG4J2-1876] Unreliable checking for runtime dependencies

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.2
• Fix Version/s: 2.9.0
• Component/s: Core
• Epic Link: Log4j2 ergonomics
• Assignee: Mikael Ståldal
• Reporter: Mikael Ståldal
• Created: 11/Apr/17 12:25
• Updated: 25/Jun/17 21:11
• Resolved: 11/Apr/17 16:08

Description

If I include this in Maven POM:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.7</version>
    <scope>runtime</scope>
    <exclusions>
        <exclusion>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
        </exclusion>
    </exclusions>
</dependency>

I get this printed on STDERR on startup:

Unknown error checking for existence of class: com.fasterxml.jackson.databind.ObjectMapper
java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/Versioned
	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$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at org.apache.logging.log4j.util.LoaderUtil.loadClass(LoaderUtil.java:141)
	at org.apache.logging.log4j.util.LoaderUtil.isClassAvailable(LoaderUtil.java:115)
	at org.apache.logging.log4j.core.util.Loader.isClassAvailable(Loader.java:310)
	at org.apache.logging.log4j.core.config.yaml.YamlConfigurationFactory.<init>(YamlConfigurationFactory.java:47)
	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.logging.log4j.core.util.ReflectionUtil.instantiate(ReflectionUtil.java:188)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.addFactory(ConfigurationFactory.java:190)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.getInstance(ConfigurationFactory.java:164)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:613)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:634)
	at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:229)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:242)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:174)
	at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:618)
	at logtest.Main.<clinit>(Main.java:14)
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.Versioned
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 33 more
Unknown error checking for existence of class: com.fasterxml.jackson.databind.ObjectMapper
java.lang.NoClassDefFoundError: com/fasterxml/jackson/core/Versioned
	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$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at org.apache.logging.log4j.util.LoaderUtil.loadClass(LoaderUtil.java:141)
	at org.apache.logging.log4j.util.LoaderUtil.isClassAvailable(LoaderUtil.java:115)
	at org.apache.logging.log4j.core.util.Loader.isClassAvailable(Loader.java:310)
	at org.apache.logging.log4j.core.config.json.JsonConfigurationFactory.<init>(JsonConfigurationFactory.java:49)
	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.logging.log4j.core.util.ReflectionUtil.instantiate(ReflectionUtil.java:188)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.addFactory(ConfigurationFactory.java:190)
	at org.apache.logging.log4j.core.config.ConfigurationFactory.getInstance(ConfigurationFactory.java:164)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:613)
	at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:634)
	at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:229)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:242)
	at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:45)
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:174)
	at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:618)
	at logtest.Main.<clinit>(Main.java:14)
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.core.Versioned
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 33 more