Improve android handling

* Do not load codegen class on android
* Autodetect android version

Author: rPraml

rhino/src/main/java/org/mozilla/javascript/Context.java

@@ -2649,7 +2649,9 @@ private static void notifyDebugger_r(Context cx, DebuggableScript dscript, Strin
     }
 
     private static Class<?> codegenClass =
-            Kit.classOrNull("org.mozilla.javascript.optimizer.Codegen");
+            ScriptRuntime.androidApi > 0
+                    ? null
+                    : Kit.classOrNull("org.mozilla.javascript.optimizer.Codegen");
     private static Class<?> interpreterClass =
             Kit.classOrNull("org.mozilla.javascript.Interpreter");
 

rhino/src/main/java/org/mozilla/javascript/NativeJavaClass.java

@@ -156,7 +156,7 @@ public Scriptable construct(Context cx, Scriptable scope, Object[] args) {
         try {
             // When running on Android create an InterfaceAdapter since our
             // bytecode generation won't work on Dalvik VM.
-            if ("Dalvik".equals(System.getProperty("java.vm.name")) && classObject.isInterface()) {
+            if (ScriptRuntime.androidApi > 0 && classObject.isInterface()) {
                 Object obj =
                         createInterfaceAdapter(
                                 classObject, ScriptableObject.ensureScriptableObject(args[0]));

rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java

@@ -8,6 +8,7 @@
 
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.math.MathContext;
@@ -297,7 +298,7 @@ public static ScriptableObject initStandardObjects(
 
     static String[] getTopPackageNames() {
         // Include "android" top package if running on Android
-        return "Dalvik".equals(System.getProperty("java.vm.name"))
+        return androidApi > 0
                 ? new String[] {"java", "javax", "org", "com", "edu", "net", "android"}
                 : new String[] {"java", "javax", "org", "com", "edu", "net"};
     }
@@ -6137,9 +6138,27 @@ public Object call(Context cx, Scriptable scope, Object[] args) {
         }
     }
 
+    private static int detectAndroidApi() {
+
+        try {
+            Class<?> versionClass = Class.forName("android.os.Build$VERSION");
+            Field sdkInt = versionClass.getField("SDK_INT");
+            return sdkInt.getInt(null);
+        } catch (NoSuchFieldException | IllegalAccessException | ClassNotFoundException e) {
+            if ("Dalvik".equals(System.getProperty("java.vm.name"))) {
+                // Fall back to vm-name
+                return 1;
+            }
+        }
+        return -1;
+    }
+
     public static final Object[] emptyArgs = new Object[0];
     public static final String[] emptyStrings = new String[0];
 
     static final XMLLoader xmlLoaderImpl =
             ScriptRuntime.loadOneServiceImplementation(XMLLoader.class);
+
+    /** This value holds the current android API version (or -1) if not running on android */
+    static final int androidApi = detectAndroidApi();
 }