[java-native-access#985] Improve handling of dynamicaly extracted nat…

…ive library.

On Mac OS X systems `~/Library/Caches/JNA/temp` and on
other Unix like systems `$XDG_CACHE_DIR/JNA/temp` (Default value is:
`~/.cache/JNA/temp`) is used.

Behaviour on windows is unchanged, as since Vista the tempdir is by
default inside the user profile directory.

Closes: java-native-access#985

CHANGES.md

@@ -33,6 +33,7 @@ Features
 * [#1007](https://github.com/java-native-access/jna/pull/1007): Added OSGi export of Solaris package - [@swimmesberger](https://github.com/swimmesberger).
 * [#1003](https://github.com/java-native-access/jna/pull/1003): Allow `NativeMapped` to be used with enums - [@koraktor](https://github.com/koraktor).
 * [#994](https://github.com/java-native-access/jna/issues/994): Added `CoInitializeSecurity` and `CoSetProxyBlanket` to `c.s.j.platform.win32.Ole32`, added new `c.s.j.platform.win32.Wbemcli` classes needed to query WMI, and added a `WbemcliUtil` class implementing WMI queries. - [@dbwiddis](https://github.com/dbwiddis).
+* [#985](https://github.com/java-native-access/jna/issues/985): Improve handling of dynamicaly extracted native library. On Mac OS X systems `~/Library/Application Support/JNA/temp` and on other Unix like systems `$XDG_CACHE_DIR/JNA/temp` (Default value is: `~/.cache/JNA/temp`) is used - [@matthiasblaesing](https://github.com/matthiasblaesing).
 
 Bug Fixes
 ---------

src/com/sun/jna/Native.java

@@ -1137,6 +1137,9 @@ else if (!Boolean.getBoolean("jna.nounpack")) {
                 if (!Boolean.getBoolean("jnidispatch.preserve")) {
                     lib.deleteOnExit();
                 }
+                if (DEBUG) {
+                    System.out.println("Extracting library to " + lib.getAbsolutePath());
+                }
                 fos = new FileOutputStream(lib);
                 int count;
                 byte[] buf = new byte[1024];
@@ -1288,10 +1291,27 @@ static File getTempDir() throws IOException {
         }
         else {
             File tmp = new File(System.getProperty("java.io.tmpdir"));
-            // Loading DLLs via System.load() under a directory with a unicode
-            // name will fail on windows, so use a hash code of the user's
-            // name in case the user's name contains non-ASCII characters
-            jnatmp = new File(tmp, "jna-" + System.getProperty("user.name").hashCode());
+            if(Platform.isMac()) {
+                // https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/MacOSXDirectories/MacOSXDirectories.html
+                jnatmp = new File(System.getProperty("user.home"), "Library/Caches/JNA/temp");
+            } else if (Platform.isLinux() || Platform.isSolaris() || Platform.isAIX() || Platform.isFreeBSD() || Platform.isNetBSD() || Platform.isOpenBSD() || Platform.iskFreeBSD()) {
+                // https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+                // The XDG_CACHE_DIR is expected to be per user
+                String xdgCacheEnvironment = System.getenv("XDG_CACHE_HOME");
+                File xdgCacheFile;
+                if(xdgCacheEnvironment == null || xdgCacheEnvironment.trim().isEmpty()) {
+                    xdgCacheFile = new File(System.getProperty("user.home"), ".cache");
+                } else {
+                    xdgCacheFile = new File(xdgCacheEnvironment);
+                }
+                jnatmp = new File(xdgCacheFile, "JNA/temp");
+            } else {
+                // Loading DLLs via System.load() under a directory with a unicode
+                // name will fail on windows, so use a hash code of the user's
+                // name in case the user's name contains non-ASCII characters
+                jnatmp = new File(tmp, "jna-" + System.getProperty("user.name").hashCode());
+            }
+
             jnatmp.mkdirs();
             if (!jnatmp.exists() || !jnatmp.canWrite()) {
                 jnatmp = tmp;

test/com/sun/jna/JNALoadTest.java

@@ -125,7 +125,7 @@ public void testLoadAndUnloadFromJar() throws Exception {
         String path = (String)field.get(null);
         assertNotNull("Native library path unavailable", path);
         assertTrue("Native library not unpacked from jar: " + path,
-                   path.startsWith(System.getProperty("java.io.tmpdir")));
+                path.startsWith(Native.getTempDir().getAbsolutePath()));
 
         Reference<Class<?>> ref = new WeakReference<Class<?>>(cls);
         Reference<ClassLoader> clref = new WeakReference<ClassLoader>(loader);