Refactoring - Version stable

src/main/java/dev/lions/unionflow/server/entity/DemandeAdhesion.java

@@ -4,6 +4,7 @@ import jakarta.persistence.*;
 import jakarta.validation.constraints.*;
 import java.math.BigDecimal;
 import java.time.LocalDateTime;
+import java.util.concurrent.atomic.AtomicLong;
 import lombok.*;
 
 /**
@@ -108,9 +109,12 @@ public class DemandeAdhesion extends BaseEntity {
         && montantPaye.compareTo(fraisAdhesion) >= 0;
   }
 
+  private static final AtomicLong REFERENCE_COUNTER =
+      new AtomicLong(System.currentTimeMillis() % 100000000L);
+
   public static String genererNumeroReference() {
     return "ADH-" + java.time.LocalDate.now().getYear()
-        + "-" + String.format("%08d", System.currentTimeMillis() % 100000000);
+        + "-" + String.format("%08d", REFERENCE_COUNTER.incrementAndGet() % 100000000L);
   }
 
   @PrePersist