How to fix this please reply

Duplicate class org.apache.commons.collections.ArrayStack found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.Buffer found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.BufferUnderflowException found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$1 found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$CollectionView found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$CollectionView$CollectionViewIterator found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$EntrySet found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$KeySet found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.apache.commons.collections.FastHashMap$Values found in modules commons-beanutils-1.8.0.jar (commons-beanutils:commons-beanutils:1.8.0) and commons-collections-3.2.1.jar (commons-collections:commons-collections:3.2.1)
Duplicate class org.w3c.dom.UserDataHandler found in modules jaxen-1.1.6.jar (jaxen:jaxen:1.1.6) and xml-apis-1.4.01.jar (xml-apis:xml-apis:1.4.01)

Start by reproducing the reported duplicate-class build failure and tracing how commons-beanutils-1.8.0.jar, commons-collections-3.2.1.jar, jaxen-1.1.6.jar, and xml-apis-1.4.01.jar enter the project. Done means the conflicting classes are no longer present together and the Java build completes successfully.

Written by the indexing model from the issue text.