Validate room image storage path

src/main/kotlin/com/android/trisolarisserver/component/RoomImageStorage.kt

@@ -17,6 +17,18 @@ class RoomImageStorage(
     @Value("\${storage.rooms.root:/home/androidlover5842/docs/rooms}")
     private val rootPath: String
 ) {
+    init {
+        val root = Paths.get(rootPath)
+        try {
+            Files.createDirectories(root)
+        } catch (ex: Exception) {
+            throw IllegalStateException("Room image root not writable: $rootPath", ex)
+        }
+        if (!Files.isWritable(root)) {
+            throw IllegalStateException("Room image root not writable: $rootPath")
+        }
+    }
+
     fun store(propertyId: UUID, roomId: UUID, file: MultipartFile): StoredRoomImage {
         val contentType = file.contentType ?: ""
         if (!contentType.startsWith("image/")) {
@@ -27,7 +39,11 @@ class RoomImageStorage(
         val ext = extensionFor(contentType, originalName)
 
         val dir = Paths.get(rootPath, propertyId.toString(), roomId.toString())
-        Files.createDirectories(dir)
+        try {
+            Files.createDirectories(dir)
+        } catch (ex: Exception) {
+            throw IllegalStateException("Failed to create room image directory: $dir", ex)
+        }
         val base = UUID.randomUUID().toString() + "_" + OffsetDateTime.now().toEpochSecond()
         val originalPath = dir.resolve("$base.$ext")
         val originalTmp = dir.resolve("$base.$ext.tmp")