Maven - ClassNotFoundException: org.apache.commons.lang.StringUtils

Question

Can someone please explain what this error is and when it occurs?

Downloading: file://C:/.../org/springframework/boot/spring-boot-dependencies/1.4.0.RELEASE/spring-boot-dependencies-1.4.0.RELEASE.pom
Exception in thread "pool-11-thread-1" ---------------------------------------------------
constituent[0]: file:/C:/Program%20Files/NetBeans%208.2/java/maven/lib/aether-api-1.13.1.jar
constituent[1]: file:/C:/Program%20Files/NetBeans%208.2/java/maven
constituent[18]: file:/C:/Program%20Files/NetBeans%208.2/java/maven/lib/plexus-component-annotations-1.5.5.jar
constituent[19]: file:/C:/Program%20Files/NetBeans%208.2/java/maven/lib/plexus-interpolation-1.14.jarjava.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils
    at org.apache.maven.wagon.providers.file.FileWagon.resolveDestinationPath(FileWagon.java:206)
    at org.apache.maven.wagon.providers.file.FileWagon.resourceExists(FileWagon.java:265)
    at org.sonatype.aether.connector.wagon.WagonRepositoryConnector$GetTask.run(WagonRepositoryConnector.java:577)
    at org.sonatype.aether.util.concurrency.RunnableErrorForwarder$1.run(RunnableErrorForwarder.java:60)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang.StringUtils
    at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
    at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
    ... 7 more

Why maven can not find org.apache.commons.lang.StringUtils . Looking into local repository I'm able to find org\\apache\\maven\\wagon\\wagon-providers\\2.7\\... and org\\apache\\commons\\parent\\... , org\\apache\\commons\\lang\\... , org\\apache\\commons\\exec\\... , org\\apache\\commons\\compress\\... , org\\apache\\commons\\pool2\\... . I can not figure out when this problem occurs, so I'm not able to resolve this problem...

Answer 1

Fixed! I have downloaded manually maven 3.5 under https://maven.apache.org/download.cgi and copied file commons-lang3-3.5.jar to C:\\Program Files\\NetBeans 8.2\\java\\maven\\lib\\ . I'm using NetBeans 8.2 with Maven as Plug-In.

Answer 2

Try adding this dependency in your pom.xml:

<dependency>
    <groupId>commons-lang</groupId>
    <artifactId>commons-lang</artifactId>
    <version>2.6</version>
</dependency>