Fixed compilation error

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/model/CustomerDto.java

@@ -17,6 +17,10 @@ public class CustomerDto {
         this.phone = c.phone;
     }
     
+    public long getId() {
+    	return this.id;
+    }
+    
     public Customer convertToEntity() {
         Customer c = new Customer();
         c.id = id;

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/service/CustomerService.java

@@ -38,7 +38,7 @@ public class CustomerService {
     }
 
     public Customer updateCustomer(CustomerDto dto) {
-        Customer myCustomer = repo.findById(dto.id);
+        Customer myCustomer = repo.findById(dto.getId());
         mapper.updateCustomerFromDto(dto, myCustomer);
         repo.save(myCustomer);
         return myCustomer;