Randomize property codes with 7-char alphabet

src/main/kotlin/com/android/trisolarisserver/controller/property/Properties.kt

@@ -39,6 +39,8 @@ class Properties(
     private val propertyUserRepo: PropertyUserRepo,
     private val appUserRepo: AppUserRepo
 ) {
+    private val codeRandom = java.security.SecureRandom()
+    private val codeAlphabet = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
 
     @PostMapping("/properties")
     @ResponseStatus(HttpStatus.CREATED)
@@ -277,8 +279,12 @@ class Properties(
     }
 
     private fun generatePropertyCode(): String {
-        repeat(10) {
-            val code = "HOTE" + (100..999).random()
+        repeat(200) {
+            val code = buildString(7) {
+                repeat(7) {
+                    append(codeAlphabet[codeRandom.nextInt(codeAlphabet.length)])
+                }
+            }
             if (!propertyRepo.existsByCode(code)) {
                 return code
             }