How to install Java native development headers on OS X Lion

Question

I'm trying to build a JNI project, but I can't seem to find the JNI headers (e.g. jni.h). I've installed "Java for Mac OS X 10.7 Developer Package" from https://developer.apple.com/downloads/.

Various online resources suggest the headers should be in locations such as /System/Library/Frameworks/JavaVM.framework/Headers or /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/include, but I can't find them anywhere -- the installer doesn't seem to be creating them.

I see other JDK components -- just for example, /System/Library/Frameworks/JavaVM.framework/Commands/javah -- but not the JNI headers. Any suggestions?

---

Update: technomage pointed out that Apple now installs the JDK under /Library/Java/JavaVirtualMachines, and the JNI headers were at /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home/include/jni.h.

But I'm still stuck on my actual goal, which is to build the JNI wrappers for LevelDB (per instructions at github.com/fusesource/leveldbjni). To point Maven at the proper JDK, I added /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home/bin to the front of my PATH, and set JAVA_HOME to /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home. After chugging for a while, Maven now fails with:

[INFO] --- maven-hawtjni-plugin:1.5:build (default) @ leveldbjni-osx ---  
[INFO] Extracting /Users/steve/leveldb/leveldbjni/leveldbjni/target/leveldbjni-99-master-SNAPSHOT-native-src.zip to /Users/steve/leveldb/leveldbjni/leveldbjni-osx/target/native-build-extracted  
[INFO] executing: /bin/sh -c ./configure --disable-ccache --prefix=/Users/steve/leveldb/leveldbjni/leveldbjni-osx/target/native-build/target --with-leveldb=/Users/steve/leveldb/leveldb --with-snappy=/Users/steve/leveldb/snappy-1.0.3 --with-universal --with-leveldb=/Users/steve/leveldb/leveldb --with-snappy=/Users/steve/leveldb/snappy-1.0.3  
...  
[INFO] configure: JAVA_HOME was set, checking to see if it's a JDK we can use...  
[INFO] checking if '/Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home' is a JDK... no  
[INFO] configure: javac was on your path, checking to see if it's part of a JDK we can use...  
[INFO] checking if '/Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home' is a JDK... no  
[INFO] configure: Taking a guess as to where your OS installs the JDK by default...  
[INFO] checking if '/System/Library/Frameworks/JavaVM.framework' is a JDK... no  
[INFO] configure: error: JDK not found. Please use the --with-jni-jdk option

I can't tell for sure what Maven is looking at to identify "a JDK we can use"? Some digging around led me to http://www.arm4.org/trac/browser/branches/architecture/m4/jni.m4 which appears to look for jni.h in a few places and try to compile it, but I don't know whether this jni.m4 has any actual relationship Maven. I do have jni.h in /Library/Java/JavaVirtualMachines/1.7.0.jdk/Contents/Home/include/.

Answer 1

I know this is an old thread, but here is what I did to get current today (Late 3/14) so I could build some Ruby GEM that needed the Java Headers. Overkill, but covers all the bases, I think.

1. Download the Java 8 JDK from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

2. Install it.

3. See where Oracle put it:

   $/usr/libexec/java_home
   /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents/Home
   

4. Symlink from there to where Apple used to put it:

   $cd /System/Library/Frameworks/JavaVM.framework/Versions
   $sudo ln -nsf /Library/Java/JavaVirtualMachines/jdk1.8.0.jdk/Contents ./CurrentJDK
   

5. Symlink to make a Headers directory in JavaVM.framewrk:

   $cd /System/Library/Frameworks/JavaVM.framework
   $sudo ln -nsf Versions/CurrentJDK/Home/include/ ./Headers
   

This fixed things for me. I haven't bothered with defining JAVA_HOME yet because I haven't needed it.