FrontEndSharedQ[link] returns True if the front end is being shared with a specified link, and returns False otherwise.

GetJavaException[] returns the Java Exception object that was thrown in the most recent call from Mathematica to Java.

JavaLink[] returns the MathLink LinkObject that is used to communicate with the J/Link Java runtime.

JavaObjectQ[expr] gives True if expr is a reference to a Java object or Null, and gives False otherwise.

SetInternetProxy[host, port] sets proxy information in your Java session for accessing the internet.

UseFrontEnd[expr] evaluates expr in an environment where the kernel can make use of the services of the notebook front end.

MLINK getMathLink (WolframLibraryData libData) gets a MathLink connection to use for evaluations in Mathematica.

mcomplex*MTensor_getComplexData (MTensor t) gets an array of the data elements of an MTensor of complex type.

mint*MTensor_getIntegerData (MTensor t) gets an array of the data elements of an MTensor of integer type.

double*MTensor_getRealData (MTensor t) gets an array of the data elements of an MTensor of real type.