Fix Mac OSX + OpenJDK builds where JAVA_HOME contains libexec but…

… not `lib` (#119)

* Allow JAVA_HOME values to contain libexec and not lib.

* Fixed bug

* Python 3.12 build

* Remove possibly unnecessary JAVA_HOME checks and improve logging.

* Recursively find the directory containing the relevant JDK files.

* Upated readme

* Better java home error message

* Fixed usage of walk.

README.md

@@ -48,6 +48,7 @@ Install a JDK 8, preferably the Oracle distribution. Set `JDK_HOME` or
 
     $ export JDK_HOME=<your-jdk-dir>
     $ export JAVA_HOME=$JDK_HOME
+    $ pip install setuptools wheel
     $ python setup.py build maven bdist_wheel
 
 On success, the wheel is found in the `dist` directory.
@@ -68,12 +69,14 @@ SDK 7.1::
     > SET DISTUTILS_USE_SDK=1
     > C:\Program Files\Microsoft SDKs\Windows\v7.1\bin\setenv /x64 /release
     > SET JDK_HOME=<your-jdk-dir>
+    > pip install setuptools wheel
     > python setup.py build maven bdist_wheel
 
 With Visual Studio 14 and higher it is much easier::
 
     > SET VS100COMNTOOLS=C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Tools\
     > SET JDK_HOME=<your-jdk-dir>
+    > pip install setuptools wheel
     > python setup.py build maven bdist_wheel
 
 On success, the wheel can be found in the `dist` directory.

jpyutil.py

@@ -136,12 +136,42 @@ def find_jdk_home_dir():
     dedicated environment variables.
     :return: pathname if found, else None
     """
+
+    def is_jdk_dir(path):
+        rst = os.path.exists(os.path.join(path, 'include')) and os.path.exists(os.path.join(path, 'lib'))
+        logger.debug(f'Checking {path} for JDK...: {"yes" if rst else "no"}')
+        return rst
+
+    def walk_to_jdk(path):
+        if is_jdk_dir(path):
+            return path
+
+        for root, dir_names, file_names in os.walk(path):
+            for d in dir_names:
+                p = os.path.join(root, d)
+
+                if p and is_jdk_dir(p):
+                    return p
+
+        return None
+
     for name in JDK_HOME_VARS:
         jdk_home_dir = os.environ.get(name, None)
-        if jdk_home_dir \
-                and os.path.exists(os.path.join(jdk_home_dir, 'include')) \
-                and os.path.exists(os.path.join(jdk_home_dir, 'lib')):
-            return jdk_home_dir
+        if jdk_home_dir:
+            logger.debug(f'JAVA_HOME set by environment variable to {jdk_home_dir}')
+
+            if is_jdk_dir(jdk_home_dir):
+                return jdk_home_dir
+
+            jdk_dir = walk_to_jdk(jdk_home_dir)
+
+            if jdk_dir:
+                logger.error(f'JAVA_HOME set by environment variable to {jdk_home_dir} but no no "include" or "lib" directory found.  Possibly you meant {jdk_dir}?')
+            else:
+                logger.error(f'JAVA_HOME set by environment variable to {jdk_home_dir} but no no "include" or "lib" directory found.  Does not appear to be a JDK directory.')
+
+            exit(1)
+
     logger.debug('Checking Maven for JAVA_HOME...')
     try:
         output = subprocess.check_output(['mvn', '-v'])
@@ -152,7 +182,9 @@ def find_jdk_home_dir():
             if part.startswith('Java home:'):
                 path = part.split(':')[1].strip()
                 if path.endswith('jre'):
-                    return path[0:-3]
+                    java_home = path[0:-3]
+                    logger.debug(f'JAVA_HOME set by maven to {java_home}')
+                    return java_home
 
     except Exception:
         # maven probably isn't installed or not on PATH