The Java Native Interface (JNI) enables non-Java programs to access Java objects and classes. One of the variants of the cobcall() method provided in the com.microfocus.cobol.RuntimeSystem class passes through a JNI pointer to the COBOL program being called. The JNI pointer is a pointer to a table of Java functions which enable non-Java code to access the Java run-time system.
For ease of use with COBOL, javatypes.cpy defines data type JNINativeInterface. JNINativeInterface is a group data item consisting of a set of procedure pointers to the JNI Java functions. One use of JNI with COBOL is to throw a Java exception from a COBOL program.
The other way to access Java from COBOL is to use the domain support, as documented in the chapter Calling Java from OO COBOL.