This version of JEP has removed the javah tool from the tools shipped with the JDK.

Suppose that you need instances of your class to be referenced by native code in C. Developers have used the javah tool to generate the C header and source files from a Java class. The generated code is used to enable native code (say, written in C) to access the instances of your Java class. The javah tool creates a .h file, which defines struct, similar to the structure of your class. For multiple classes in a source file, the javah tool generates separate .h files.

The removal of javah doesn't imply any decline in the usage of your Java classes by the native code.

With Java 8, javah was enhanced to take on the responsibility of generating the C header and source code files. After testing over two versions, javah is being removed from Java SE 10.