Class XQException

An exception that provides information on XQJ, XQuery or other errors reported by an XQJ implementation.

Each XQException provides several kinds of information:

• a string describing the error. This is used as the Java Exception message, available via the method getMessage.
• the cause of the error. This is used as the Java Exception cause, available via the method getCause.
• the vendor code identifying the error. Available via the method getVendorCode. Refer to the vendor documentation which specific codes can be returned.
• a chain of XQException objects. If more than one error occurred the exceptions are referenced via this chain.

Note that XQException has a subclass XQQueryException providing more detailed information about errors that occurred during the processing of a query. An implementation throws a base XQException when an error occurs in the XQJ implementation. Further, implementations are encouraged to use the more detailed XQQueryException in case of an error reported by the XQuery engine.

It is possible that during the processing of a query that one or more errors could occur, each with their own potential causal relationship. This means that when an XQJ application catches an XQException, there is a possibility that there may be additional XQException objects chained to the original thrown XQException. To access the additional chained XQException objects, an application would recursively invoke getNextException until a null value is returned.

An XQException may have a causal relationship, which consists of one or more Throwable instances which caused the XQException to be thrown. The application may recursively call the method getCause, until a null value is returned, to navigate the chain of causes.