JNIWrapper: Fall back to system library if not found in .jar.

This is useful primarily for debugging purposes (as the temporary file
written by the loader can't be easily loaded by gdb).

Change-Id: Ic4ea22ef88363c5ff998980b0352844645766fd9

wpilibj/src/athena/java/edu/wpi/first/wpilibj/hal/JNIWrapper.java

@@ -14,34 +14,37 @@ public class JNIWrapper {
   static {
     try {
       if (!libraryLoaded) {
-        // create temporary file
-        jniLibrary = File.createTempFile("libwpilibJavaJNI", ".so");
-        // flag for delete on exit
-        jniLibrary.deleteOnExit();
-
-        byte[] buffer = new byte[1024];
-
-        int readBytes;
-
         InputStream is = JNIWrapper.class.getResourceAsStream("/linux-arm/libwpilibJavaJNI.so");
+        if (is != null) {
+          // create temporary file
+          jniLibrary = File.createTempFile("libwpilibJavaJNI", ".so");
+          // flag for delete on exit
+          jniLibrary.deleteOnExit();
 
-        OutputStream os = new FileOutputStream(jniLibrary);
+          byte[] buffer = new byte[1024];
 
-        try {
-          while ((readBytes = is.read(buffer)) != -1) {
-            os.write(buffer, 0, readBytes);
+          int readBytes;
+
+
+          OutputStream os = new FileOutputStream(jniLibrary);
+
+          try {
+            while ((readBytes = is.read(buffer)) != -1) {
+              os.write(buffer, 0, readBytes);
+            }
+
+          } finally {
+            os.close();
+            is.close();
           }
-
-        } finally {
-          os.close();
-          is.close();
+          System.load(jniLibrary.getAbsolutePath());
+        } else {
+          System.loadLibrary("wpilibJavaJNI");
         }
 
-
         libraryLoaded = true;
       }
 
-      System.load(jniLibrary.getAbsolutePath());
     } catch (Exception ex) {
       ex.printStackTrace();
       System.exit(1);