Update app.py

app.py

@@ -5,6 +5,16 @@ st.set_page_config(page_title="Android Build Server", layout="centered")
 st.title("📱 Android APK Generator")
 st.markdown("Flutter ya Native Android — dono projects ka APK banayega aur **Auto-Sign** karega.")
 
+def setup_java_env():
+    # Automatically detect valid JAVA_HOME path from system java binary
+    current_jh = os.environ.get("JAVA_HOME", "")
+    if not current_jh or not os.path.exists(os.path.join(current_jh, "bin", "java")):
+        java_bin = shutil.which("java")
+        if java_bin:
+            real_path = os.path.realpath(java_bin)
+            detected_jh = os.path.dirname(os.path.dirname(real_path))
+            os.environ["JAVA_HOME"] = detected_jh
+
 def generate_keystore():
     kp = "debug.keystore"
     if not os.path.exists(kp):
@@ -42,6 +52,8 @@ f = st.file_uploader("Project ZIP Upload Karein", type=["zip"])
 
 if f is not None:
     if st.button("🔨 Create & Sign APK"):
+        setup_java_env()  # Auto detect and set JAVA_HOME
+        
         sts = st.empty(); bar = st.progress(0)
         if os.path.exists("project_extract"): shutil.rmtree("project_extract")
         os.makedirs("project_extract")