CMake cannot find Java on Linux “Could NOT find Java (missing: Java_JAVAH_EXECUTABLE)”

Question

I'm encountering a CMake error suggesting it cannot find Java (JDK I think?):

Could NOT find Java (missing: Java_JAVAH_EXECUTABLE) (found version
  "1.8.0_181")

However, when I run:

which javac

I get:

/bin/javac

but setting:

export JAVA_HOME=/bin/javac

and re-compiling does not solve the problem.

Anybody encountered this before?

Answer 1

It looks like cmake is looking for javah not javac . You're using Java 1.8, so you should have javah installed. (It has been removed in a later version, and instead of javah you're supposed to use javac -h )

Make sure cmake can find the javah tool by setting JAVA_HOME so that it points at the Java 8 installation directory (typically under /usr/lib/jvm on a Linux system)

Answer 2

I have encountered the same problem, but with a different cause. I post my problem and solution below, hoping to save others' troubleshooting time.

problem:

The CMake reported an error much like the thread title:

CMake Error at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:108 (message):
  Could NOT find Java (missing: Java_JAVAH_EXECUTABLE) (found version
  "11.0.7")
Call Stack (most recent call first):
  /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:315 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake/Modules/FindJava.cmake:191 (find_package_handle_standard_args)
  CMakeLists.txt:20 (find_package)

analysis:

Look at the file /usr/share/cmake/Modules/FindJava.cmake . It is found that _JAVA_HINTS and _JAVA_PATHS do not include my java version.

solution:

Use a new version CMake that supports my java version