I am trying to implement domain driven design in my project.
Here is my base Aggregate class:
public abstract class UUIDAggregate {
private final DomainEventPublisher domainEventPublisher;
protected void publish(DomainEvent domainEvent) {
domainEventPublisher.publish(domainEvent);
}
}
Let's say we have UserAccount aggregate:
public class UserAccount extends UUIDAggregate {
private String email;
private String username;
private String password;
private String firstName;
private String lastName;
public void update() {
publish(new DomainEventImpl());
}
}
Here is my DomainEventPublisher:
public interface DomainEventPublisher {
void publish(DomainEvent event);
}
Here is DomainEventPublisherImpl:
#Component
public class DomainEventPublisherImpl implements DomainEventPublisher{
#Autowired
private ApplicationEventPublisher publisher;
public void publish(DomainEvent event){
publisher.publishEvent(event);
}
}
Now, this seems like a good idea, the domain is separated from implementation but this does not work. DomainEventPublisher cannot be Autowired because UUIDAggregate is not a #Component or #Bean . One solution would be to create DomainService and publish event there but that seems like leaking of domain to domain service and if I go that way, I am going to anemic model. Also what I can do is to pass DomainEventPublisher as a parameter to every aggregate but that also does not seems like a good idea.
One idea would be to have a factory for domain objects:
#Component
class UserAccountFactoryImpl implements UserAccountFactory {
#Autowired
private DomainEventPublisher publisher;
#Override
public UserAccount newUserAccount(String email, String username, ...) {
return new UserAccount(email, username, ..., publisher);
}
}
Then your code creating a domain object is "publisher-free":
UserAccount userAccount = factory.newUserAccount("john#example.com", ...);
Or you might slightly change the design of the event-publishing:
public abstract class UUIDAggregate {
private final List<DomainEvent> domainEvents = new ArrayList<>();
protected void publish(DomainEvent domainEvent) {
domainEvents.add(domainEvent);
}
public List<DomainEvent> domainEvents() {
return Collections.unmodifiableList(domainEvents);
}
}
#Component
class UserAccountServiceImpl implements UserAccountService {
#Autowired
private DomainEventPublisher publisher;
#Override
public void updateUserAccount(UserAccount userAccount) {
userAccount.update();
userAccount.domainEvents().forEach(publisher::publishEvent);
}
}
This is different from your proposal: the service publishes the events, but doesn't create then - the logic stays in the domain object.
Further, you can change your publisher to minimize the boiler-plate code:
public interface DomainEventPublisher {
void publish(UUIDAggregate aggregate);
}
Vaughn Vernon in his book IDDD just uses singleton like this:
DomainEventPublisher.instance().register(...);
DomainEventPublisher.instance().publish(...);
I know this approach doesn't use spring injection but it's much simplier than passing publisher to every aggregate and not that hard to test.
Related
I'm newbie with Java. I'm create an API with Webflux and ReactiveMongoRepository.
I try to save my data from another API.
My repository:
#Repository
public interface AccountApiTrackingRepo extends ReactiveMongoRepository<AccountApiTracking, String> {
}
My service implements:
#Override
public void findByIdAccountsApiTrack(User user, String accountId){
AccountApiTracking accountApiTracking = new AccountApiTracking();
accountApiTracking.setUser(user);
accountApiTracking.setAccountId(accountId);
accountApiTracking.setAction("Find account by Id");
System.out.println(accountApiTracking);
accountApiTrackingRepo.save(accountApiTracking);
}
My services:
#Service
public interface AccountApiTrackingService {
public void createAccountsApiTrack(User user, AccountDto accountDto);
public void findByIdAccountsApiTrack(User user, String accountId);
Flux<AccountApiTrackingDto> findAll();
}
My model:
#Document
#Data
#NoArgsConstructor
#AllArgsConstructor
public class AccountApiTracking implements AutoMapping<AccountApiTrackingDto> {
#Id
private String id;
private User user;
private String action;
private AccountDto payload;
private String accountId;
#Override
public String toString() {
return String.valueOf(action);
}
}
After function findByIdAccountsApiTrack() run I can't find any document created in my database.
I can see my variable accountApiTracking have data. But accountApiTrackingRepo.save doesn't work.
What I'm missing?
In Reactive programming should subscribe to any reactive instruction.
you should
return accountApiTrackingRepo.save(accountApiTracking);
to till your usage for example in the controller.
or for your test case, you can use ".subscribe()" after your method call.
I am dealing with multiple entity classes but they have the same attributes.
It's not a good data structure but according to my use case, I have to deal with two entities having the same attributes. As of now I am using multiple controllers, multiple request/response and multiple interfaces and implementations to do the logic part and save into the two corresponding tables.
Is there any efficient way that I could combine both into a single interface, with the DB operations happening in multiple DBs.
Following is a sample code:
#RestController
..
public class FooController {
#Autowired
private FooService fooService;
#GetMapping
public FooResponse findFoo(
#PathVariable(FOO_CONSTANT.PATH_VARIABLE_FOO_ID) String fooId)
throws FooException {
return fooService.findFoo(fooId));
}
}
public interface FooService{
FooResponse findFoo(String fooId);
}
#Service
public class ProspectAssetServiceImpl implements ProspectAssetService {
#Autowired
private FooRepository fooRepository;
#Override
public FooResponse findFoo(String fooId){
FooEntity fooEntity = fooRepository.findByFooId(fooId));
return convertBomToMessaging(fooEntity);
}
}
public class Foo {
private String fooId;
private String fooName;
//getters and setters
}
#Entity
#Table(name = "foo_table")
public class FooEntity {
private String fooId;
private String fooName;
//getters and setters
}
Second Service:
#RestController
..
public class ZooController {
#Autowired
private ZooService ZooService;
#GetMapping
public ZooResponse findZoo(
#PathVariable(Zoo_CONSTANT.PATH_VARIABLE_Zoo_ID) String ZooId)
throws ZooException {
return ZooService.findZoo(ZooId));
}
}
public interface ZooService{
ZooResponse findZoo(String ZooId);
}
#Service
public class ProspectAssetServiceImpl implements ProspectAssetService {
#Autowired
private ZooRepository ZooRepository;
#Override
public ZooResponse findZoo(String ZooId){
ZooEntity ZooEntity = ZooRepository.findByZooId(ZooId));
return convertBomToMessaging(ZooEntity);
}
}
public class Zoo {
private String ZooId;
private String ZooName;
//getters and setters
}
#Entity
#Table(name = "Zoo_table")
public class ZooEntity {
private String ZooId;
private String ZooName;
//getters and setters
}
Suggest me an efficient way to combine these two together?
What I would like to achieve is to use interfaces for domain classes and generic types for service layer and be able to change the implementation of the persistence layer from current which is MongoDb to e.g. JPA. Interfaces for domain classes are necessary because of e.g different annotations for JPA and MongoDB (#Entity and #Document).
Let's look at the structure of the following demo project:
For each element of the domain model there can be three interfaces, let's explain it using the user package:
User - representation of domain object
UserDao - providing persistence layer methods
UserService - providing business logic methods
Here are interfaces for each of them:
public interface User {
String getId();
String getFirstName();
String getLastName();
List<Consent> getConsents();
Boolean getBlocked();
}
public interface UserDao <UserType extends User> {
UserType save(UserType user);
Optional<UserType> getById(String userId);
}
public interface UserService <UserType extends User> {
UserType create(String firstName, String lastName);
void addConsent(UserType user, ConsentType consentType);
}
As I mentioned earlier, current implementation of those interfaces is related to Mongo DB:
#Getter
#Setter
#Document(collection = "user")
public class MongoUser extends AbstractMongoCollection implements User {
private String firstName;
private String lastName;
private List<PojoConsent> consents;
private Boolean blocked;
void addConsent(PojoConsent consent) {
if(consents == null) {
consents = new ArrayList<>();
}
consents.add(consent);
}
#Override
public List<Consent> getConsents() {
return new ArrayList<>(consents);
}
}
#Component
public class MongoUserDao implements UserDao<MongoUser> {
private MongoUserRepository mongoUserRepository;
#Autowired
public MongoUserDao(MongoUserRepository mongoUserRepository) {
this.mongoUserRepository = mongoUserRepository;
}
#Override
public MongoUser save(MongoUser user) {
return mongoUserRepository.save(user);
}
#Override
public Optional<MongoUser> getById(String userId) {
return mongoUserRepository.findByIdAndDeletedIsFalse(userId);
}
}
#Component
public class MongoUserService implements UserService<MongoUser> {
private UserDao<MongoUser> userDao;
#Autowired
public MongoUserService(UserDao<MongoUser> userDao) {
this.userDao = userDao;
}
#Override
public MongoUser create(String firstName, String lastName) {
MongoUser user = new MongoUser();
user.setBlocked(false);
user.setFirstName(firstName);
user.setLastName(lastName);
user.setDeleted(false);
return userDao.save(user);
}
#Override
public void addConsent(MongoUser user, ConsentType consentType) {
PojoConsent pojoConsent = new PojoConsent();
pojoConsent.setActive(true);
pojoConsent.setType(consentType);
pojoConsent.setDate(LocalDateTime.now());
user.addConsent(pojoConsent);
userDao.save(user);
}
}
Ok, so what is the problem ? The problem occurs when I inject beans of type UserDao and UserService in other beans (as it happens in Spring Framework), like EntryPoint in this example (I'm aware of that there should be no logic in spring controller, but this is just an example):
#RestController
#RequestMapping("/api")
public class EntryPoint {
#Autowired
private ConversationService conversationService;
#Autowired
private UserDao userDao;
#PostMapping("/create/{userId}")
public ResponseEntity<String> createConversation(#PathVariable("userId") String userId) {
Optional<User> optionalUser = userDao.getById(userId);
if(optionalUser.isPresent()) {
User user = optionalUser.get();
Conversation conversation = conversationService.create(user, "default");
return ResponseEntity.ok(conversation.getId());
}
return ResponseEntity.notFound().build();
}
}
Interfaces ConversationService and UserDao have a generic type so warnings appear:
I don't want to give up generic types but on the other hand I'm aware that injecting without generic types will cause warnings which does not comply with clean code principles. It is true that this design will work despite warnings. I don't want to change implementation of the EntryPoint when I change persistence layer from MongoDb to JPA, I just want to provide new implementation for domain interfaces (User, UserDao, UserService etc.)
How to reconcile the interface issue for domain domain classes and injecting without generic type ?
I have a simple project, based on this guide. I created a simple REST interface and I want it to use my database. I added Hibernate to the dependencies and created the DAO class. I'm using Spring Tool-Suite for IDE. As far as I understand I should add some beans to tell the classes what to use but I don't understand how. Here are my classes.
Application.java
package com.learnspring.projectfirst;
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
Marker.java
package com.learnspring.projectfirst;
#Entity
public class Marker {
#Id
#Column
#GeneratedValue(strategy=GenerationType.AUTO)
private long id;
#Column
private double longitude;
#Column
private double latitude;
#Column
private String address;
public Marker() {
// Empty constructor
}
public Marker(long id, double longitude, double latitude, String address) {
this.id = id;
this.longitude = longitude;
this.latitude = latitude;
this.address = address;
}
//Getters and Setters
}
MarkerController.java
package com.learnspring.projectfirst.controller;
#Controller
public class MarkerController {
private Logger logger = Logger.getLogger(MarkerController.class.getName());
#Autowired
private MarkerServiceImplementation markerService;
#RequestMapping(value="/markers", method=RequestMethod.GET)
public #ResponseBody List<Marker> getMarkers(#RequestParam(value="city", defaultValue="") String city) {
return this.markerService.getAllMarkers();
}
#RequestMapping(value="/markers/new", method=RequestMethod.POST)
public #ResponseBody Marker addMarker(#RequestBody Marker marker) {
this.markerService.addMarker(marker);
return marker;
}
}
MarkerDaoImplementation.java
package com.learnspring.projectfirst.dao;
#Repository
public class MarkerDaoImplementation implements MarkerDaoInterface {
#Autowired
private SessionFactory sessionFactory;
#Override
public void addMarker(Marker marker) {
this.sessionFactory.getCurrentSession().save(marker);
}
#Override
public void deleteMarker(int markerId) {
this.sessionFactory.getCurrentSession().delete(this.getMarker(markerId));
}
#Override
public Marker getMarker(int markerId) {
return (Marker) this.sessionFactory.getCurrentSession().get(Marker.class, markerId);
}
#Override
public List<Marker> getAllMarkers() {
return this.sessionFactory.getCurrentSession().createQuery("from Marker").list();
}
}
MarkerServiceImplementation.java
package com.learnspring.projectfirst.service;
#Service
public class MarkerServiceImplementation implements MarkerServiceInterface {
#Autowired
private MarkerDaoImplementation markerDao;
#Transactional
public void addMarker(Marker marker) {
this.markerDao.addMarker(marker);
}
#Transactional
public void deleteMarker(int markerId) {
this.markerDao.deleteMarker(markerId);
}
#Transactional
public Marker getMarker(int markerId) {
return this.markerDao.getMarker(markerId);
}
#Transactional
public List<Marker> getAllMarkers() {
return this.markerDao.getAllMarkers();
}
}
And here is the file structure:
I understand that I should tell my program the database name and the columns using beans but I don't understand how. How can I link the java code to the beans? Sorry I pasted so much code, I just wanted to make sure you have everything needed. Thank you in advance!
This is the one you need: Spring Boot with MySQL
Refer this example : Spring MVC with JdbcTemplate Example
The annotations in your "Marker" class determine the MySQL table and column names (based on the class and class variable names). The tablename will be "marker", with the columns "id", "longitude", "latitude", "address".
You forgot the most important part in your code: your spring configuration. it determines how the SessionFactory instance will be initialized before being injected into your DAO class. Here you have to set an appropriate connection to the MySQL Server (e.g. via an JNDI Resource)
I have a collection called Products in my MongoDB database, which is represented by the interface IProductPrice in my Java code. The following repository declaration causes Spring Date to look to the collection db.collection: Intelliprice.iProductPrice.
I want it to configure it to look in db.collection: Intelliprice.Products using an external configuration rather than putting an #Collection(..) annotation on IProductPrice. Is this possible? How can I do this?
public interface ProductsRepository extends
MongoRepository<IProductPrice, String> {
}
The only way you can currently achieve this is by annotating your domain class with #Document using the collection property to define the name of the collection instances of this class shall be persisted to.
However, there's a JIRA issue open that suggests adding a pluggable naming strategy to configure the ways class, collection and property names are handled in a more global way. Feel free to comment your use case and vote it up.
using answer from Oliver Gierke above,
working on a project where I need to create multiple collections for one entity, I wanted to use the spring repositories and needed to specify the entity to use before using the repository.
I managed to modify the repository collection name on demand using this system, it using SPeL. You can only work on 1 collection at a time though.
Domain object
#Document(collection = "#{personRepository.getCollectionName()}")
public class Person{}
Default Spring Repository:
public interface PersonRepository
extends MongoRepository<Person, String>, PersonRepositoryCustom{
}
Custom Repository Interface:
public interface PersonRepositoryCustom {
String getCollectionName();
void setCollectionName(String collectionName);
}
implementation:
public class PersonRepositoryImpl implements PersonRepositoryCustom {
private static String collectionName = "Person";
#Override
public String getCollectionName() {
return collectionName;
}
#Override
public void setCollectionName(String collectionName) {
this.collectionName = collectionName;
}
}
To use it:
#Autowired
PersonRepository personRepository;
public void testRetrievePeopleFrom2SeparateCollectionsWithSpringRepo(){
List<Person> people = new ArrayList<>();
personRepository.setCollectionName("collectionA");
people.addAll(personRepository.findAll());
personDocumentRepository.setCollectionName("collectionB");
people.addAll(personRepository.findAll());
Assert.assertEquals(4, people.size());
}
Otherwise if you need to use configuration variables, you could maybe use something like this? source
#Value("#{systemProperties['pop3.port'] ?: 25}")
A little late,
but I've found you can set the mongo collection name dynamically in spring-boot accessing the application configuration directly.
#Document(collection = "#{#environment.getProperty('configuration.property.key')}")
public class DomainModel {...}
I suspect you can set any annotation attribute this way.
The only comment I can add is that you have to add # prefix to the bean name:
collection = "#{#beanName.method()}"
for the bean factory to inject the bean:
#Document(collection = "#{#configRepositoryCustom.getCollectionName()}")
public class Config {
}
I struggled to figure it out..
COMPLETE EXAMPLE:
#Document(collection = "#{#configRepositoryCustom.getCollectionName()}")
public class Config implements Serializable {
#Id
private String uuid;
private String profile;
private String domain;
private String label;
private Map<String, Object> data;
// get/set
}
public interface ConfigRepositoryCustom {
String getCollectionName();
void setCollectionName(String collectionName);
}
#Component("configRepositoryCustom")
public class ConfigRepositoryCustomImpl implements ConfigRepositoryCustom {
private static String collectionName = "config";
#Override
public String getCollectionName() {
return collectionName;
}
#Override
public void setCollectionName(String collectionName) {
this.collectionName = collectionName;
}
}
#Repository("configurations")
public interface ConfigurationRepository extends MongoRepository<Config, String>, ConfigRepositoryCustom {
public Optional<Config> findOneByUuid(String Uuid);
public Optional<Config> findOneByProfileAndDomain(String profile, String domain);
}
usage in serviceImpl:
#Service
public class ConfigrationServiceImpl implements ConfigrationService {
#Autowired
private ConfigRepositoryCustom configRepositoryCustom;
#Override
public Config create(Config configuration) {
configRepositoryCustom.setCollectionName( configuration.getDomain() ); // set the collection name that comes in my example in class member 'domain'
Config configDB = configurationRepository.save(configuration);
return configDB;
}
I use static class and method in SpEL;
public class CollectionNameHolder {
private static final ThreadLocal<String> collectionNameThreadLocal = new ThreadLocal<>();
public static String get(){
String collectionName = collectionNameThreadLocal.get();
if(collectionName == null){
collectionName = DataCenterApiConstant.APP_WECHAT_DOCTOR_PATIENT_COLLECTION_NAME;
collectionNameThreadLocal.set(collectionName);
}
return collectionName;
}
public static void set(String collectionName){
collectionNameThreadLocal.set(collectionName);
}
public static void reset(){
collectionNameThreadLocal.remove();
}
}
In Entity class ,#Document(collection = "#{T(com.test.data.CollectionNameHolder).get()}")
And then ,use
CollectionNameHolder.set("testx_"+pageNum)
in Service , and
CollectionNameHolder.reset();
Hope it helps you.