Xerces uses the ObjectFactory class to load some classes dynamically, e.g. the parser configuration. The ObjectFactory finds the specified implementation class by querying the system property, reading META-INF/services/factoryId FILE or using a FALLBACK classname. After the implementation is found, the ObjectFactory tries to load the file using the context classloader and if it is null, the ObjectFactory uses the system classloader.

If you run Xerces in an environment, such as WebSphere® Application Server, that has multiple classloaders you may get ClassCastExceptions thrown from Xerces because different classloaders might get INVOLVED in loading Xerces classes. For example, ClassCastExceptions may occur when utility EAR classes that use Xerces load Xerces classes from WAR modules.

We suggest you read the "Avoiding ClassCastExceptions..." article which explains a workaround for this PROBLEM. Also you might want to read the "J2EE Class Loading Demystified" article that explains how multiple classloaders work in WebSphere Application Server.

Xerces uses the ObjectFactory class to load some classes dynamically, e.g. the parser configuration. The ObjectFactory finds the specified implementation class by querying the system property, reading META-INF/services/factoryId file or using a fallback classname. After the implementation is found, the ObjectFactory tries to load the file using the context classloader and if it is null, the ObjectFactory uses the system classloader.

If you run Xerces in an environment, such as WebSphere® Application Server, that has multiple classloaders you may get ClassCastExceptions thrown from Xerces because different classloaders might get involved in loading Xerces classes. For example, ClassCastExceptions may occur when utility EAR classes that use Xerces load Xerces classes from WAR modules.

We suggest you read the "Avoiding ClassCastExceptions..." article which explains a workaround for this problem. Also you might want to read the "J2EE Class Loading Demystified" article that explains how multiple classloaders work in WebSphere Application Server.