WebFlux check before save - spring

New to WebFlux.
Tell me how to implement validation before saving
If there is no Customer with this Email || Phone then save, if there is then RuntimeError
I did not find the exact solution, I want it to be beautiful
public Mono<CustomerDto> createCustomer(CustomerDto customerDto) {
return customerRepository.findByEmailOrPhone(customerDto.getEmail(), customerDto.getPhone())
.switchIfEmpty(Mono.just(customerConverter.convertDto(customerDto))
.flatMap(customerRepository::save)
)
.map(customerConverter::convertDocument);
}

This should be implemented via composite key for ID:
#Data
#Builder
#NoArgsConstructor
#AllArgsConstructor
public class CustomerId implements Serializable {
private String email;
private String phone;
}
#Data
#Document
public class Customer {
#org.springframework.data.annotation.Id
private CustomerId id;
}
You will replace default ObjectId with custom composite key and gain all database constrains like unique and non-null.
There would be no need for any checks on service layer at all. You would have to translate db exception to business logic exception and finally show a popup to user that he can't use email or phone cause it already exists.
Please take into the account relatively new validation feature that could be used in here as well: https://www.mongodb.com/docs/manual/core/schema-validation/

Related

Spring boot REST API best way to choose in client side which field to load

Hi I have implemented a mock solution to my problem and I'm pretty sure something better already exist.
Here's that I want to achieve :
I have created a point to load categories with or without subCategories
/api/categories/1?fields=subCategories
returns
{
"id":"1",
"name":"test",
"subCategories":[{
"id":"1",
"name":"test123"
}]
}
/api/categories/1
returns
{
"id":"1",
"name":"test"
}
My entities
#Entity
class Category{
#Id
private String id;
private String name;
private Set<SubCategory> subCategories;
}
#Entity
class SubCategory{
#Id
private String id;
private String name;
}
I have removed services since this is not the point.
I've created CategoryDTO and SubCategoryDTO classes with the same fields as Category and SubCategory
The converter
class CategoryDTOConverter{
CategoryDTO convert(Category category,String fields){
CategoryDTO dto=new CategoryDTO();
dto.setName(category.getName());
if(StringUtils.isNotBlank(fields) && fields.contains("subCategories"){
category.getSubCategories().forEach(s->{
dto.getSubcategories().add(SubCategoryDTOConverter.convert(s));
}
}
}
}
I used com.cosium.spring.data.jpa.entity.graph.repository to create an EntityGraph from a list of attribute path
#Repository
interface CategoryRepository extends EntityGraphJpaRepository<Category, String>{
Optional<T> findById(String id,EntityGraph entityGraph);
}
Controller
#RestController
#CrossOrigin
#RequestMapping("/categories")
public class CategoryController {
#GetMapping(value = "/{id}")
public ResponseEntity<CategoryDTO> get(#PathVariable("id") String id, #RequestParam(value="fields",required=false) String fields ) throws Exception {
Optional<Category> categOpt=repository.findById(id,fields!=null?EntityGraphUtils.fromAttributePaths(fields):null);
if(categOpt.isEmpty())
throws new NotFoundException();
return ResponseEntity.ok(categoryDTOConverter.convert(categOpt.get(),fields);
}
}
This is a simple example to illustrate what I need to do
I don't want to load fields that clients doesn't want to use
How could I do this in a better way ?
Take a look at GraphQL since it is a perfect match for your use case. With GraphQL it is the client that decides which attributes it wants to receive by providing in the POST request body exactly which attributes are needed to be included in the response. This is way more manageable than trying to handle all this on your own.
Spring Boot recently added its own Spring GraphQL library, so it is quite simple to integrate it in your Spring Boot app.

Spring Data Rest Does Not Update Default Value in DB

I have a Spring Boot application using Spring Data REST. I have a domain entity called User with a boolean field isTeacher. This field has been already setup by our DBA in the User table with type bit and a default value of 1:
#Data
#Entity
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id; // This Id has been setup as auto generated in DB
#Column(name = "IS_TEACHER")
private boolean isTeacher;
}
And the User repository:
public interface UserRepository extends CrudRepository<User, Long>{
}
I was able to add a new user by giving the below request and POST to http://localhost:8080/users, a new user was created in the DB having isTeacher value 1:
{
"isTeacher" : true
}
However, when I tried to change IS_TEACHER by giving PATCH (or PUT) and this request:
{
"isTeacher" : false
}
The response showed that "isTeacher" is still true and the value didn't get changed in the table either. Can someone please let me know why this is happening?
The issue is due to #Data annotation of lombok is ignoring if you have a field that start with isXx it generates getters and setters to boolean with isTeacher for getters and setTeacher for setters then you are not able to update correctly your property, if you put "teacher" when updating should work but you should solve this by overriding that setter.
#Setter(AccessLevel.NONE) private boolean isTeacher;
public void setIsTeacher(boolean isTeacher) {
this.isTeacher = isTeacher;
}

How do I get Spring's Data Rest Repository to retrieve data by its name instead of its id

I am using Spring Data's Rest Repositories from spring-boot-starter-data-rest, with Couchbase being used as the underlining DBMS.
My Pojo for the object is setup as so.
#Document
public class Item{
#Id #GeneratedValue(strategy = UNIQUE)
private String id;
#NotNull
private String name;
//other items and getters and setters here
}
And say the Item has an id of "xxx-xxx-xxx-xxx" and name of "testItem".
Problem is, that when I want to access the item, I need to be accessible by /items/testItem, but instead it is accessible by /items/xxx-xxx-xxx-xxx.
How do I get use its name instead of its generated id, to get the data.
I found out the answer to my own question.
I just need to override the config for the EntityLookup.
#Component
public class SpringDataRestCustomization extends RepositoryRestConfigurerAdapter {
#Override
public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config) {
config.withEntityLookup().forRepository(UserRepository.class).
withIdMapping(User::getUsername).
withLookup(UserRepository::findByUsername);
}
}
Found the info here, though the method name changed slightly.
https://github.com/spring-projects/spring-data-examples/tree/master/rest/uri-customization
If you want query the item by name and want it perform as querying by id,you should make sure the name is unique too.You cant identify a explicit object by name if all objects have a same name,right?
With jpa you could do it like:
#NotNull
#Column(name="name",nullable=false,unique=true)
private String name;

Spring Repository issue

I seem to be baffled on how JPA Repositories are suppose to work.
In a nut-shell
#Entity
public class User extends AbstractEntity {
protected final static String FK_NAME = "USER_ID";
#Column(nullable = false)
private String firstName;
#OneToMany(cascade = ALL, fetch = FetchType.LAZY, orphanRemoval = true)
#JoinColumn(name = "userId")
private List<Detail> details = new ArrayList<Detail>();
}
#Entity
public class Detail extends AbstractEntity {
Long userId;
String hello;
}
#Repository
public interface UserRepository extends CrudRepository<User, Long> {
User findByFirstName(#Param("firstName") String firstName);
}
And here is the only controller in the app:
#RestController
public class Home {
#Autowired
UserRepository userRepository;
#Autowired
DetailsRepository loanRepository;
#RequestMapping(value = "")
public HttpEntity home() {
User user = userRepository.findByFirstName("John");
if (user == null) {
user = new User();
user.setFirstName("John");
}
Detail detail = new Detail();
detail.setHello("Hello Msh");
user.getDetails().add(detail);
userRepository.save(user);
return new ResponseEntity("hi", HttpStatus.OK);
}
}
Below a screenshot from debugging session where the app just started and the get request to home() method creates new user, new detail, adds detail to user.
Below example - when the user is saved, the detail entity gets updated
Now on the next request, the old user John is found and has been added a new instance of detail.
The old user has been saved but now the newly created detail does not get updated outside.
How come this only works first time ?
Basically theres so much fail going on so that I would advise you to go a step backwards. If youre wana go the short path of getting a solution for exactly this problem continue reading ;)
First part related to the answer of Jaiwo99:
As I can see in the gradle view of intellij, your using Spring Boot. So it is necessary to place #EnableTransactionManagement on top of your configuration class. Otherwise the #Transacion annotation does not have any effect.
Second part your JPA/Hibernate model mapping. Theres so much bad practise on the net that it is no wonder that most beginners have troubles starting with it.
A correct version could look like (not tested)
#Entity
public class User extends AbstractEntity {
#Column(nullable = false)
private String firstName;
#OneToMany(cascade = ALL, fetch = FetchType.LAZY, orphanRemoval = true, mappedBy="user")
private List<Detail> details = new ArrayList<Detail>();
public void addDetail(Detail detail) {
details.add(detail);
detail.setUser(user);
}
}
#Entity
public class Detail extends AbstractEntity {
#ManyToOne
private User user;
private String hello;
public void setUser(User user){
this.user = user;
}
}
Some general advice related to creating a model mapping:
avoid bi-directional mappings whenever possible
cascade is a decision made on the service level and not at the model level and can have huge drawbacks. So for beginners avoid it.
I have no idea why people like to put JoinColumn, JoinTable and whatever join annotation on top of fields. The only reason to do this is when you have a legacy db (my opinion). When you do not like the names created by your jpa provider, provide a different naming strategy.
I would provide a custom name for the user class, because this is in some databases a reserved word.
Very simple, the first time you saved a new entity outside of hibernate session, the second time, the user object you got is a detached object, by default hibernate will not consider it is changed in this case.
*solution *
Move this logic to another service class, which annotated with #transactional
Or
Annotate your controller with transactional
Or
Override equals and hashCode method on user class may also help

ID field is null in controller

I am using spring mvc with hibernate and JPA. I have a Person class which is inherited by another class called Agent. The mapping is implemented as follows:
#Entity
#Table(name = "Person")
#Inheritance(strategy = InheritanceType.JOINED)
public class Person extends Auditable implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "PersonId")
protected Long id;
//other variables
...
}
#Entity
#PrimaryKeyJoinColumn(name = "PersonId")
public class Agent extends Person implements Serializable {
//additional agent specific variables go here
...
}
Saving new data is smooth and I have no problem there. however, when I edit data, everything except the id value is bound to the controller method's model attribute. I have verified that the id has been sent along with other items from the browser using chrome's developer tools. but the id field at the controller is always null and as a result the data is not updated. This is what my controller method looks like:
#RequestMapping(value = "register", method = RequestMethod.POST)
public #ResponseBody CustomAjaxResponse saveAgent(ModelMap model, #ModelAttribute("agent") #Valid Agent agent, BindingResult result) {
...
}
I suspect the problem is probably with my inheritance mapping because I have other classes inheriting from the Person class and I face a similar problem there as well.
Please help!
you need a public setter for id.
In cases like this I commonly use a specific dto for the form, and/or implement a conversion service that retrieves the entity via hibernate based on id and then performs a merge.

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