Java Native Interface (thing)

The Java Native Interface (JNI) allows programmers
to write Java code which interacts with native code written
in other languages, such as C, C++, or assembly language. JNI can be used to write
native methods when the Java language is not
suitable for the task, such as:

• Java is not fast enough for a time-critical section of an application
• Java's class library doesn't have platform-specific features required by the application
• Using a library which already exists in another language rather than reimplementing it in Java

The native code can use and update Java objects, call Java code, and throw Java exceptions. JNI can be thought
of as the "glue" between Java and native code.