Update app.py

app.py

@@ -32,6 +32,7 @@ ANDROID_SDK_DIR = os.path.join(BASE_DIR, "android-sdk")
 FLUTTER_SDK_DIR = os.path.join(BASE_DIR, "flutter")
 
 def ensure_java_home():
+    # 1. Try finding javac/java from system PATH
     javac_bin = shutil.which("javac") or shutil.which("java")
     if javac_bin:
         try:
@@ -43,17 +44,32 @@ def ensure_java_home():
         except Exception:
             pass
 
-    candidates = [
-        "/usr/lib/jvm/java-17-openjdk-amd64",
-        "/usr/lib/jvm/java-17-openjdk-arm64",
-        "/usr/lib/jvm/java-17-openjdk",
-        "/usr/lib/jvm/default-java",
-        "/usr/lib/jvm/java-11-openjdk-amd64",
-    ]
-    for c in candidates:
-        if os.path.exists(os.path.join(c, "bin", "java")):
-            os.environ["JAVA_HOME"] = c
-            return c
+    # 2. Check Debian JVM folder
+    jvm_base = "/usr/lib/jvm"
+    if os.path.exists(jvm_base):
+        for item in sorted(os.listdir(jvm_base), reverse=True):
+            candidate = os.path.join(jvm_base, item)
+            if os.path.isdir(candidate) and os.path.exists(os.path.join(candidate, "bin", "java")):
+                os.environ["JAVA_HOME"] = candidate
+                return candidate
+
+    # 3. Fallback: Download Portable OpenJDK 17 if system Java is missing
+    portable_jdk = os.path.join(BASE_DIR, "jdk17")
+    java_bin_check = os.path.join(portable_jdk, "bin", "java")
+    if not os.path.exists(java_bin_check):
+        print("⏬ System Java missing. Downloading Portable OpenJDK 17...")
+        tar_path = os.path.join(BASE_DIR, "openjdk17.tar.gz")
+        url = "https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.10%2B7/OpenJDK17U-jdk_x64_linux_hotspot_17.0.10_7.tar.gz"
+        subprocess.run(["curl", "-sSL", url, "-o", tar_path])
+        os.makedirs(portable_jdk, exist_ok=True)
+        subprocess.run(["tar", "-xzf", tar_path, "-C", portable_jdk, "--strip-components=1"])
+        if os.path.exists(tar_path):
+            os.remove(tar_path)
+
+    if os.path.exists(java_bin_check):
+        os.environ["JAVA_HOME"] = portable_jdk
+        return portable_jdk
+
     return ""
 
 def init_environment():