centralize StringUtils usage

backend/src/main/java/com/petshop/backend/controller/AuthController.java

@@ -25,7 +25,6 @@ import com.petshop.backend.service.EmailService;
 import com.petshop.backend.service.PasswordResetService;
 import com.petshop.backend.util.AuthenticationHelper;
 import com.petshop.backend.util.ImageValidationUtil;
-import com.petshop.backend.util.PhoneUtils;
 import com.petshop.backend.util.StringUtils;
 import jakarta.validation.Valid;
 import org.springframework.core.io.Resource;
@@ -84,7 +83,7 @@ public class AuthController {
         String email = StringUtils.trimToNull(request.getEmail());
         String firstName = StringUtils.trimToNull(request.getFirstName());
         String lastName = StringUtils.trimToNull(request.getLastName());
-        String phone = normalizePhone(request.getPhone());
+        String phone = StringUtils.normalizePhone(request.getPhone());
 
         if (userRepository.findByUsername(username).isPresent()) {
             log.warn("Registration rejected: username already exists ({})", username);
@@ -107,7 +106,7 @@ public class AuthController {
         user.setEmail(email);
         user.setFirstName(firstName);
         user.setLastName(lastName);
-        user.setFullName(joinFullName(firstName, lastName));
+        user.setFullName(StringUtils.fullName(firstName, lastName));
         user.setPhone(phone);
         user.setRole(User.Role.CUSTOMER);
         user.setActive(true);
@@ -219,11 +218,11 @@ public class AuthController {
             user.setLastName(lastName);
         }
         if (firstName != null || lastName != null) {
-            user.setFullName(joinFullName(user.getFirstName(), user.getLastName()));
+            user.setFullName(StringUtils.fullName(user.getFirstName(), user.getLastName()));
         }
 
         if (request.getPhone() != null) {
-            String phone = normalizePhone(request.getPhone());
+            String phone = StringUtils.normalizePhone(request.getPhone());
             if (!java.util.Objects.equals(phone, user.getPhone())) {
                 if (phone != null && userRepository.findByPhone(phone)
                         .filter(existing -> !existing.getId().equals(user.getId()))
@@ -258,7 +257,7 @@ public class AuthController {
         Long customerId = user.getRole() == User.Role.CUSTOMER ? user.getId() : null;
         String fullName = user.getFullName();
         if (fullName == null || fullName.isBlank()) {
-            fullName = joinFullName(user.getFirstName(), user.getLastName());
+            fullName = StringUtils.fullName(user.getFirstName(), user.getLastName());
         }
         return new UserInfoResponse(
                 user.getId(),
@@ -277,22 +276,6 @@ public class AuthController {
         );
     }
 
-    private String normalizePhone(String value) {
-        return StringUtils.trimToNull(PhoneUtils.normalize(StringUtils.trimToNull(value)));
-    }
-
-    private String joinFullName(String firstName, String lastName) {
-        String first = StringUtils.trimToNull(firstName);
-        String last = StringUtils.trimToNull(lastName);
-        if (first == null) {
-            return last == null ? null : last;
-        }
-        if (last == null) {
-            return first;
-        }
-        return first + " " + last;
-    }
-
     @PostMapping("/me/avatar")
     public ResponseEntity<AvatarUploadResponse> uploadAvatar(@RequestParam("avatar") MultipartFile file) {
         User user = getAuthenticatedUser();

backend/src/main/java/com/petshop/backend/controller/DropdownController.java

@@ -3,6 +3,7 @@ package com.petshop.backend.controller;
 import com.petshop.backend.dto.common.DropdownOption;
 import com.petshop.backend.entity.User;
 import com.petshop.backend.repository.*;
+import com.petshop.backend.util.StringUtils;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.*;
@@ -68,7 +69,7 @@ public class DropdownController {
     public ResponseEntity<List<DropdownOption>> getCustomers() {
         return ResponseEntity.ok(
             userRepository.findByRoleAndActiveTrue(User.Role.CUSTOMER).stream()
-                .map(u -> new DropdownOption(u.getId(), u.getFirstName() + " " + u.getLastName()))
+                .map(u -> new DropdownOption(u.getId(), StringUtils.fullName(u.getFirstName(), u.getLastName())))
                 .sorted(Comparator.comparing(DropdownOption::getLabel, String.CASE_INSENSITIVE_ORDER))
                 .collect(Collectors.toList())
         );
@@ -90,7 +91,7 @@ public class DropdownController {
         return ResponseEntity.ok(
                 userRepository.findByRoleAndActiveTrue(User.Role.CUSTOMER).stream()
                         .filter(u -> customersWithPets.contains(u.getId()))
-                        .map(u -> new DropdownOption(u.getId(), u.getFirstName() + " " + u.getLastName()))
+                        .map(u -> new DropdownOption(u.getId(), StringUtils.fullName(u.getFirstName(), u.getLastName())))
                         .sorted(Comparator.comparing(DropdownOption::getLabel, String.CASE_INSENSITIVE_ORDER))
                         .collect(Collectors.toList())
         );
@@ -190,7 +191,7 @@ public class DropdownController {
         }
         return ResponseEntity.ok(
                 employees.stream()
-                        .map(u -> new DropdownOption(u.getId(), u.getFirstName() + " " + u.getLastName()))
+                        .map(u -> new DropdownOption(u.getId(), StringUtils.fullName(u.getFirstName(), u.getLastName())))
                         .sorted(Comparator.comparing(DropdownOption::getLabel, String.CASE_INSENSITIVE_ORDER))
                         .collect(Collectors.toList())
         );

backend/src/main/java/com/petshop/backend/service/ActivityLogService.java

@@ -6,6 +6,7 @@ import com.petshop.backend.entity.StoreLocation;
 import com.petshop.backend.entity.User;
 import com.petshop.backend.repository.ActivityLogRepository;
 import com.petshop.backend.repository.UserRepository;
+import com.petshop.backend.util.StringUtils;
 import jakarta.persistence.criteria.Predicate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -48,7 +49,10 @@ public class ActivityLogService {
             entry.setUser(managedUser);
             entry.setStore(store);
             entry.setUsernameSnapshot(managedUser.getUsername());
-            entry.setFullNameSnapshot(resolveFullName(managedUser));
+            String fullName = managedUser.getFullName() != null && !managedUser.getFullName().isBlank()
+                    ? managedUser.getFullName()
+                    : StringUtils.fullName(managedUser.getFirstName(), managedUser.getLastName());
+            entry.setFullNameSnapshot(fullName);
             entry.setRoleSnapshot(managedUser.getRole() != null ? managedUser.getRole().name() : null);
             entry.setStoreNameSnapshot(store != null ? store.getStoreName() : null);
             entry.setActivity(activity.trim());
@@ -127,7 +131,10 @@ public class ActivityLogService {
         if (entry.getUser() != null) {
             response.setUserId(entry.getUser().getId());
             response.setUsername(firstNonBlank(entry.getUsernameSnapshot(), entry.getUser().getUsername()));
-            response.setFullName(firstNonBlank(entry.getFullNameSnapshot(), resolveFullName(entry.getUser())));
+            String liveName = entry.getUser().getFullName() != null && !entry.getUser().getFullName().isBlank()
+                    ? entry.getUser().getFullName()
+                    : StringUtils.fullName(entry.getUser().getFirstName(), entry.getUser().getLastName());
+            response.setFullName(firstNonBlank(entry.getFullNameSnapshot(), liveName));
             response.setRole(firstNonBlank(entry.getRoleSnapshot(), entry.getUser().getRole() != null ? entry.getUser().getRole().name() : null));
         }
 
@@ -147,24 +154,6 @@ public class ActivityLogService {
         return response;
     }
 
-    private String resolveFullName(User user) {
-        if (user == null) {
-            return null;
-        }
-        if (user.getFullName() != null && !user.getFullName().isBlank()) {
-            return user.getFullName();
-        }
-        String first = user.getFirstName();
-        String last = user.getLastName();
-        if (first == null || first.isBlank()) {
-            return last;
-        }
-        if (last == null || last.isBlank()) {
-            return first;
-        }
-        return first.trim() + " " + last.trim();
-    }
-
     private String firstNonBlank(String preferred, String fallback) {
         if (preferred != null && !preferred.isBlank()) {
             return preferred;

backend/src/main/java/com/petshop/backend/service/AdoptionService.java

@@ -256,9 +256,9 @@ public class AdoptionService {
             adoption.getPet().getPetId(),
             adoption.getPet().getPetName(),
             adoption.getCustomer().getId(),
-            adoption.getCustomer().getFirstName() + " " + adoption.getCustomer().getLastName(),
+            StringUtils.fullName(adoption.getCustomer().getFirstName(), adoption.getCustomer().getLastName()),
             adoption.getEmployee().getId(),
-            adoption.getEmployee().getFirstName() + " " + adoption.getEmployee().getLastName(),
+            StringUtils.fullName(adoption.getEmployee().getFirstName(), adoption.getEmployee().getLastName()),
             sourceStore != null ? sourceStore.getStoreId() : null,
             sourceStore != null ? sourceStore.getStoreName() : null,
             adoption.getAdoptionDate(),

backend/src/main/java/com/petshop/backend/service/AnalyticsService.java

@@ -8,6 +8,7 @@ import com.petshop.backend.entity.User;
 import com.petshop.backend.repository.InventoryRepository;
 import com.petshop.backend.repository.ProductRepository;
 import com.petshop.backend.repository.SaleRepository;
+import com.petshop.backend.util.StringUtils;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -181,12 +182,12 @@ public class AnalyticsService {
             if (sale.getIsRefund()) {
                 continue;
             }
-            String employeeName = sale.getEmployee().getFirstName() + " " + sale.getEmployee().getLastName();
+            String employeeName = StringUtils.fullName(sale.getEmployee().getFirstName(), sale.getEmployee().getLastName());
             employeeRevenue.merge(employeeName, sale.getTotalAmount(), BigDecimal::add);
         }
 
         if (user.getRole() == User.Role.STAFF && employeeRevenue.isEmpty()) {
-            String employeeName = user.getFirstName() + " " + user.getLastName();
+            String employeeName = StringUtils.fullName(user.getFirstName(), user.getLastName());
             employeeRevenue.put(employeeName, BigDecimal.ZERO);
         }
 

backend/src/main/java/com/petshop/backend/service/AppointmentService.java

@@ -324,7 +324,7 @@ public class AppointmentService {
         response.setAppointmentId(appointment.getAppointmentId());
         if (appointment.getCustomer() != null) {
             response.setCustomerId(appointment.getCustomer().getId());
-            response.setCustomerName(appointment.getCustomer().getFirstName() + " " + appointment.getCustomer().getLastName());
+            response.setCustomerName(StringUtils.fullName(appointment.getCustomer().getFirstName(), appointment.getCustomer().getLastName()));
         }
         if (appointment.getStore() != null) {
             response.setStoreId(appointment.getStore().getStoreId());
@@ -339,7 +339,7 @@ public class AppointmentService {
         response.setAppointmentStatus(appointment.getAppointmentStatus());
         if (appointment.getEmployee() != null) {
             response.setEmployeeId(appointment.getEmployee().getId());
-            response.setEmployeeName(appointment.getEmployee().getFirstName() + " " + appointment.getEmployee().getLastName());
+            response.setEmployeeName(StringUtils.fullName(appointment.getEmployee().getFirstName(), appointment.getEmployee().getLastName()));
         }
         response.setPetName(pet != null ? pet.getPetName() : null);
         response.setPetId(pet != null ? pet.getPetId() : null);

backend/src/main/java/com/petshop/backend/service/EmailService.java

@@ -7,6 +7,7 @@ import com.petshop.backend.entity.Message;
 import com.petshop.backend.entity.Sale;
 import com.petshop.backend.entity.SaleItem;
 import com.petshop.backend.entity.User;
+import com.petshop.backend.util.StringUtils;
 import com.resend.Resend;
 import com.resend.services.emails.model.CreateEmailOptions;
 import org.slf4j.Logger;
@@ -246,7 +247,7 @@ public class EmailService {
         String date = appointment.getAppointmentDate() != null ? appointment.getAppointmentDate().format(DATE_FMT) : "—";
         String time = appointment.getAppointmentTime() != null ? appointment.getAppointmentTime().format(TIME_FMT) : "—";
         String employee = appointment.getEmployee() != null
-                ? appointment.getEmployee().getFirstName() + " " + appointment.getEmployee().getLastName() : "—";
+                ? StringUtils.fullName(appointment.getEmployee().getFirstName(), appointment.getEmployee().getLastName()) : "—";
         String pet = appointment.getPet() != null ? appointment.getPet().getPetName() : null;
         return """
                 <div style="font-family:sans-serif;max-width:600px;margin:auto">

backend/src/main/java/com/petshop/backend/service/PetService.java

@@ -330,7 +330,7 @@ public class PetService {
             pet.getCreatedAt(),
             pet.getUpdatedAt(),
             owner != null ? owner.getId() : null,
-            owner != null ? owner.getFirstName() + " " + owner.getLastName() : null,
+            owner != null ? StringUtils.fullName(owner.getFirstName(), owner.getLastName()) : null,
             store != null ? store.getStoreId() : null,
             store != null ? store.getStoreName() : null
         );

backend/src/main/java/com/petshop/backend/service/SaleService.java

@@ -334,7 +334,7 @@ public class SaleService {
 
         if (sale.getEmployee() != null) {
             response.setEmployeeId(sale.getEmployee().getId());
-            response.setEmployeeName(sale.getEmployee().getFirstName() + " " + sale.getEmployee().getLastName());
+            response.setEmployeeName(StringUtils.fullName(sale.getEmployee().getFirstName(), sale.getEmployee().getLastName()));
         }
 
         if (sale.getStore() != null) {
@@ -344,7 +344,7 @@ public class SaleService {
 
         if (sale.getCustomer() != null) {
             response.setCustomerId(sale.getCustomer().getId());
-            response.setCustomerName(sale.getCustomer().getFirstName() + " " + sale.getCustomer().getLastName());
+            response.setCustomerName(StringUtils.fullName(sale.getCustomer().getFirstName(), sale.getCustomer().getLastName()));
         }
 
         response.setTotalAmount(sale.getTotalAmount());

backend/src/main/java/com/petshop/backend/service/UserService.java

@@ -90,7 +90,7 @@ public class UserService {
         user.setLastName(request.getLastName());
         user.setFullName(request.getFullName());
         user.setEmail(request.getEmail());
-        user.setPhone(StringUtils.trimToNull(request.getPhone()));
+        user.setPhone(StringUtils.normalizePhone(request.getPhone()));
         user.setRole(request.getRole());
         user.setStaffRole(StringUtils.trimToNull(request.getStaffRole()));
         user.setPrimaryStore(resolveStore(request.getPrimaryStoreId()));
@@ -134,7 +134,7 @@ public class UserService {
         user.setLastName(request.getLastName());
         user.setFullName(request.getFullName());
         user.setEmail(request.getEmail());
-        String phone = StringUtils.trimToNull(request.getPhone());
+        String phone = StringUtils.normalizePhone(request.getPhone());
         if (!Objects.equals(user.getPhone(), phone)) {
             validateUniquePhone(phone, user.getId());
         }