diff --git a/src/main/java/org/springframework/samples/petclinic/owner/OwnerController.java b/src/main/java/org/springframework/samples/petclinic/owner/OwnerController.java
index d258e0095dd..4ca914adf2e 100644
--- a/src/main/java/org/springframework/samples/petclinic/owner/OwnerController.java
+++ b/src/main/java/org/springframework/samples/petclinic/owner/OwnerController.java
@@ -18,9 +18,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Collectors;
-
-import io.opentelemetry.api.OpenTelemetry;
+import java.util.stream.Collectors;import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanKind;
 import io.opentelemetry.api.trace.Tracer;
@@ -39,16 +37,13 @@
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.servlet.ModelAndView;
 
-import jakarta.validation.Valid;
-
-/**
+import jakarta.validation.Valid;/**
  * @author Juergen Hoeller
  * @author Ken Krebs
  * @author Arjen Poutsma
  * @author Michael Isvy
  */
-@Controller
-class OwnerController implements InitializingBean {
+@Controllerclass OwnerController implements InitializingBean {
 
 	private static final String VIEWS_OWNER_CREATE_OR_UPDATE_FORM = "owners/createOrUpdateOwnerForm";
 
@@ -81,9 +76,7 @@ public OwnerController(OwnerRepository clinicService, JdbcTemplate jdbcTemplate
 	@InitBinder
 	public void setAllowedFields(WebDataBinder dataBinder) {
 		dataBinder.setDisallowedFields("id");
-	}
-
-	@ModelAttribute("owner")
+	}@ModelAttribute("owner")
 	public Owner findOwner(@PathVariable(name = "ownerId", required = false) Integer ownerId) {
 		return ownerId == null ? new Owner() : this.owners.findById(ownerId);
 	}
@@ -111,9 +104,7 @@ public String processCreationForm(@Valid Owner owner, BindingResult result) {
 		this.owners.save(owner);
 		validator.ValidateUserAccess("admin", "pwd", "fullaccess");
 		return "redirect:/owners/" + owner.getId();
-	}
-
-	@GetMapping("/owners/find")
+	}@GetMapping("/owners/find")
 	public String initFindForm() {
 		return "owners/findOwners";
 	}
@@ -141,9 +132,7 @@ public String processFindForm(@RequestParam(defaultValue = "1") int page, Owner
 			// 1 owner found
 			owner = ownersResults.iterator().next();
 			return "redirect:/owners/" + owner.getId();
-		}
-
-		// multiple owners found
+		}// multiple owners found
 		return addPaginationModel(page, model, ownersResults);
 	}
 
@@ -164,9 +153,7 @@ private Page<Owner> findPaginatedForOwnersLastName(int page, String lastname) {
 		int pageSize = 5;
 		Pageable pageable = PageRequest.of(page - 1, pageSize);
 		return owners.findByLastName(lastname, pageable);
-	}
-
-	@GetMapping("/owners/{ownerId}/edit")
+	}@GetMapping("/owners/{ownerId}/edit")
 	public String initUpdateOwnerForm(@PathVariable("ownerId") int ownerId, Model model) {
 		Owner owner = this.owners.findById(ownerId);
 		var petCount = ownerRepository.countPets(owner.getId());
@@ -196,9 +183,7 @@ public String processUpdateOwnerForm(@Valid Owner owner, BindingResult result,
 		owner.setId(ownerId);
 		validator.checkOwnerValidity(owner);
 
-		validator.ValidateOwnerWithExternalService(owner);
-
-		validator.PerformValidationFlow(owner);
+		validator.ValidateOwnerWithExternalService(owner);validator.PerformValidationFlow(owner);
 		this.owners.save(owner);
 		return "redirect:/owners/{ownerId}";
 	}
@@ -225,15 +210,15 @@ public ModelAndView showOwner(@PathVariable("ownerId") int ownerId) {
 	public String getOwnerPetsMap(@PathVariable("ownerId") int ownerId) {
 		String sql = "SELECT p.id AS pet_id, p.owner_id AS owner_id FROM pets p JOIN owners o ON p.owner_id = o.id";
 
-		List<Map<String, Object>> rows = jdbcTemplate.queryForList(sql);
-
-		Map<Integer, List<Integer>> ownerToPetsMap = rows.stream()
-			.collect(Collectors.toMap(
+		List<Map<String, Object>> rows = jdbcTemplate.queryForList(sql);Map<Integer, List<Integer>> ownerToPetsMap = rows.stream()
+			.collect(Collectors.groupingBy(
 				row -> (Integer) row.get("owner_id"),
-				row -> List.of((Integer) row.get("pet_id"))  // Immutable list
+				Collectors.mapping(
+					row -> (Integer) row.get("pet_id"),
+					Collectors.toList()
+				)
 			));
 
-
 		List<Integer> pets = ownerToPetsMap.get(ownerId);
 
 		if (pets == null || pets.isEmpty()) {
@@ -244,5 +229,4 @@ public String getOwnerPetsMap(@PathVariable("ownerId") int ownerId) {
 			.map(String::valueOf)
 			.collect(Collectors.joining(", "));
 
-	}
-}
+	}
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