raise if it's not a regular file

Author: kirklandsign

extension/android/executorch_android/src/main/java/org/pytorch/executorch/Module.java

@@ -53,7 +53,8 @@ public static Module load(final String modelPath, int loadMode) {
     if (!NativeLoader.isInitialized()) {
       NativeLoader.init(new SystemDelegate());
     }
-    if (!new File(modelPath).canRead()) {
+    File modelFile = new File(modelPath);
+    if (!modelFile.canRead() || !modelFile.isFile()) {
       throw new RuntimeException("Cannot load model path " + modelPath);
     }
     return new Module(new NativePeer(modelPath, loadMode));

extension/android/executorch_android/src/main/java/org/pytorch/executorch/extension/llm/LlmModule.java

@@ -48,10 +48,12 @@ private static native HybridData initHybrid(
    */
   public LlmModule(
       int modelType, String modulePath, String tokenizerPath, float temperature, String dataPath) {
-    if (!new File(modulePath).canRead()) {
+    File modelFile = new File(modulePath);
+    if (!modelFile.canRead() || !modelFile.isFile()) {
       throw new RuntimeException("Cannot load model path " + modulePath);
     }
-    if (!new File(tokenizerPath).canRead()) {
+    File tokenizerFile = new File(tokenizerPath);
+    if (!tokenizerFile.canRead() || !tokenizerFile.isFile()) {
       throw new RuntimeException("Cannot load tokenizer path " + tokenizerPath);
     }
     mHybridData = initHybrid(modelType, modulePath, tokenizerPath, temperature, dataPath);