diff --git a/.DS_Store b/.DS_Store
index 95d9c98..a97af01 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/.github/.DS_Store b/.github/.DS_Store
new file mode 100644
index 0000000..a42de40
Binary files /dev/null and b/.github/.DS_Store differ
diff --git a/.github/workflows/.DS_Store b/.github/workflows/.DS_Store
new file mode 100644
index 0000000..63353ce
Binary files /dev/null and b/.github/workflows/.DS_Store differ
diff --git a/.github/workflows/aws-codeguru-reviewer.yml b/.github/workflows/aws-codeguru-reviewer.yml
new file mode 100644
index 0000000..37bac9d
--- /dev/null
+++ b/.github/workflows/aws-codeguru-reviewer.yml
@@ -0,0 +1,44 @@
+name: GitHub Actions Demo
+run-name: ${{ github.actor }} is testing out GitHub Actions 🚀
+on:
+  push:
+    branches: [main, mingTest] 
+  pull_request:
+    branches: [main]
+jobs:
+  Explore-GitHub-Actions:
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+    steps:
+      - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
+      - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!"
+      - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."
+      - run: echo "TEST secret ${{ secrets.TEST_SECRET_1 }}"
+      - name: List files in the repository
+        run: |
+          ls ${{ github.workspace }}
+      - run: echo "🍏 This job's status is ${{ job.status }}."
+      - name: Checkout repository
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0 # This is a required field for CodeGuru
+      - name: Configure AWS Credentials
+        uses: aws-actions/configure-aws-credentials@v1
+        with:
+          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          aws-region: us-east-1
+      - name: CodeGuru Reviewer
+        uses: aws-actions/codeguru-reviewer@v1.1
+        with:
+          s3_bucket: codeguru-reviewer-ming-bucket # S3 Bucket with "codeguru-reviewer-*" prefix
+      - name: Upload review result
+        if: ${{ github.event_name == 'push' }}
+        uses: github/codeql-action/upload-sarif@v2
+        with:
+          sarif_file: codeguru-results.sarif.json
+      - run: |
+          ls
\ No newline at end of file
diff --git a/src/main/java/com/journaldev/spring/controller/FileUploadController.java b/src/main/java/com/journaldev/spring/controller/FileUploadController.java
index ec71bf3..06976d1 100644
--- a/src/main/java/com/journaldev/spring/controller/FileUploadController.java
+++ b/src/main/java/com/journaldev/spring/controller/FileUploadController.java
@@ -99,8 +99,11 @@ String uploadMultipleFileHandler(@RequestParam("name") String[] names,
 				// Creating the directory to store file
 				String rootPath = System.getProperty("catalina.home");
 				File dir = new File(rootPath + File.separator + "tmpFiles");
-				if (!dir.exists())
-					dir.mkdirs();
+				if (!dir.exists()) {
+					if (!dir.mkdirs()) {
+		                throw new RuntimeException("Failed to create " +rootPath + File.separator + "tmpFiles dir.");
+		            }
+				}
 
 				// Create the file on server
 				File serverFile = new File(dir.getAbsolutePath()
diff --git a/src/main/java/com/journaldev/spring/controller/PDFhighlightDemo.java b/src/main/java/com/journaldev/spring/controller/PDFhighlightDemo.java
index 1d1bf16..28c4e24 100644
--- a/src/main/java/com/journaldev/spring/controller/PDFhighlightDemo.java
+++ b/src/main/java/com/journaldev/spring/controller/PDFhighlightDemo.java
@@ -23,10 +23,11 @@ public PDFhighlightDemo()  throws IOException {
 
         public static void main(String[] args)  throws IOException {
         	
-        	String rootPath = System.getProperty("catalina.home");
-			File dir = new File(rootPath + File.separator + "tmpFiles");
-			if (!dir.exists())
-				dir.mkdirs();
+//        	String rootPath = System.getProperty("catalina.home");
+//			File dir = new File(rootPath + File.separator + "tmpFiles");
+//			if (!dir.exists()) 
+//				dir.mkdirs();
+//			
 			
             PDDocument document = null;
             String fileName = "/Users/mqzhu/apache-tomcat-9.0.69/tmpFiles/saturdayprelimsdeepprogram_032348.pdf";
diff --git a/target/classes/com/journaldev/spring/controller/FileUploadController.class b/target/classes/com/journaldev/spring/controller/FileUploadController.class
index a77e10e..443f3d2 100644
Binary files a/target/classes/com/journaldev/spring/controller/FileUploadController.class and b/target/classes/com/journaldev/spring/controller/FileUploadController.class differ
diff --git a/target/classes/com/journaldev/spring/controller/PDFhighlightDemo.class b/target/classes/com/journaldev/spring/controller/PDFhighlightDemo.class
index 6bf34c8..a9203e7 100644
Binary files a/target/classes/com/journaldev/spring/controller/PDFhighlightDemo.class and b/target/classes/com/journaldev/spring/controller/PDFhighlightDemo.class differ