Insert query
#Insert(onConflict = OnConflictStrategy.REPLACE)
long insertProduct(Product product); //product id is auto generated
view model
public Completable insertProduct(final String productName) {
return new CompletableFromAction(() -> {
Product newProduct = new Product();
newProduct.setProductName(productName);
mProductDataSource.insertOrUpdateProduct(newProduct);
});
}
In activity where I called this above function I used CompositeDisposable.
CompositeDisposable mDisposable = new CompositeDisposable();
mDisposable.add(mViewModel.insertProduct(productName))
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(() ->{} ,throwable -> Log.e(TAG, "Error msg", throwable)));
Am I implementing in wrong way?
According to docs. If the #Insert method receives only 1 parameter, it can return a long, which is the new rowId for the inserted item. If the parameter is an array or a collection, it should return long[] or List instead.
Since you insert only one item, the method will return only one rowID.
So, try this
Single.fromCallable(new Callable<Long>() {
#Override
public Long call() throws Exception {
return productDao.insertProduct(new Product()));
}
})
.subscribe(id -> {
} ,throwable -> Log.e(TAG, "Error msg", throwable)))
You could use Observable or Maybe as well. But I think Single fits better since in your case the id is autogenerated and the insertion should always complete.
Related
I have created a spring Webflux application. In this application, we are trying to retrieve a record from the DB and then use that record to complete further processing.
I have wrapped my repository.get() method within a Mono like below:
find()
#NotNull
private Mono<RuntimeCallbackDetails> find(DealsFulfilmentCallback callback, DealsFulfilmentCallbackStatus status) {
String entityId = callback.getEntityId();
String itemId = callback.getItemId();
String type = getCallbackType(callback.getEntityId());
Long fulfilmentId = Optional.ofNullable(callback.getFId()).orElse(-1L);
return fulfilmentAcknowledgementService.findFulfilmentAcknowledgement(entityId, itemId, fulfilmentId, type)
.map(acknowledgement -> {
validationService.validate(acknowledgement, CALLBACK);
return RuntimeCallbackDetails.from(callback, acknowledgement, status);
})
.doOnError(throwable -> log.error("Error while retrieving fulfilment acknowledgement for callback: ", throwable))
.switchIfEmpty(Mono.defer(() -> Mono.just(RuntimeCallbackDetails.from(callback, status))));
}
FulfilmentAcknowledgementService.findFulfilmentAcknowledgement()
#org.jetbrains.annotations.NotNull
public Mono<FulfilmentAcknowledgement> findFulfilmentAcknowledgement(String entityId, String itemId, Long fulfilmentId, String type) {
return Mono.justOrEmpty(fulfilmentAcknowledgementRepository.findFulfilmentAcknowledgement(entityId, itemId, fulfilmentId, type));
}
Now the challenge here is that the flow does not even wait for the find method to execute and return the record. It moves on and since nothing is retrieved, an empty response is propagated downstream. How do I make this find method execute the query and return the Mono based on this retrieved element?
I working on a Quarkus + MongoDB Reactive+ Mutiny application. I have a Person object and Event Object. I am creating a new event for a person. My uri looks like this
POST /person/{personId}/event
I need to first check if the person exists in MongoDB. If the person exists then save event. If person does not exist then create a Error Status and return. I am tried everything but I am stuck and getting error that required return type is Uni but required type is Uni. I tried with transformToUni as well but it did not work. Also tried few other ways like onItemOrFailure() etc. but nothing seems to work.
Here's the full Code.
public class EventResource {
#Inject
EventRepository eventRepository;
#Inject
PersonRepository personRepository;
#POST
#Path("/{person_id}/event")
public Uni<Response> create(Event event, #PathParam("person_id") String personId){
//Check if personId exist.
Uni<Person> uniPerson = personRepository.getPersonById(personId);
//THIS WORKS BUT ON FAILURE IS TREATED WHEN ERROR IS RAISED FOR EeventRepository.craete() and not if person is not found.
/*return uniPerson.onItem().ifNotNull()
.transformToUni(pid -> eventRepository.create(event, pid.getId()))
.onItem().transform(e -> Response.ok().entity(e).build())
.onFailure()
.recoverWithItem(f-> {
AStatus status = createErrorStatus(f.getMessage());
return Response.serverError().entity(status).build();
});
*/
Uni<Response> eventResp = uniPerson.onItem().transform(person -> {
if(person==null)
return Response.serverError().build();
else{
return eventRepository.create(event, person.getId())
.onItem().transform(event1 -> Response.ok(event1).build());
}
});
return eventResp;
}
You can use mutiny ifNull:
#POST
#Path("/{person_id}/event")
public Uni<Response> create(Event event, #PathParam("person_id") String personId){
return personRepository
.getPersonById(personId)
.onItem().ifNotNull().transformToUni(person -> createEvent(event, person))
.onItem().ifNull().continueWith(this::personNotFound)
// This onFailure will catch all the errors
.onFailure()
.recoverWithItem(f-> {
AStatus status = createErrorStatus(f.getMessage());
return Response.serverError().entity(status).build();
});
}
private Uni<Response> createEvent(Event event, Person person) {
return eventRepository
.create(event, person.getId())
.map( e -> Response.ok().entity(e).status(CREATED).build())
}
private Response personNotFound() {
return Response.serverError().build();
}
The error you are seeing is because when the item is not null, you are returning a Uni<Uni<Response>>. This is one way to fix it:
Uni<Response> eventResp = uniPerson
.chain(person -> {
if (person==null)
return Uni.createFrom().item(Response.serverError().build());
else {
return eventRepository
.create(event, person.getId())
.map(event1 -> Response.ok(event1).build());
}
});
I'm using map and chain because they are shorter, but you can replace them with onItem().transform(...) and onItem().transformToUni(...).
I'm trying to complete a general repository for all of the entities in my application. I Have a BaseEntity with property Id, CreatorId and LastModifiedUserId. Now I'd like to Update a record in a collection, without having to modify the field CreatorId, so I have (from the client) an Entity valorized with some fields updated that I want to update.
Hi have 2 ways:
UpdateOneAsync
ReplaceOneAsync
The repo is created like this:
public class BaseRepository<T> : IRepository<T> where T : BaseEntity
{
public async Task<T> Replace/Update(T entity){...}
}
So it's very hard to use Update(1), since I should retrieve with reflection all the fields of T and exclude the ones that I don't want to update.
With Replace(2) I cannot find a way to specify which fields i should exclude when replacing an object with another. Projectionproperty in FindOneAndReplaceOptions<T>() just excludes the fields on the document that is returned after the update.
Am I missing a way in the replace method to exclude the fields or should I try to retrieve the fields with reflection and use a Update?
I don't know if this solution is ok for you .. what i do is :
Declare in Base Repo a method like
public virtual bool Update(TEntity entity, string key)
{
var result = _collection.ReplaceOne(x => x.Id.Equals(key), entity, new UpdateOptions
{
IsUpsert = false
});
return result.IsAcknowledged;
}
then in your controller when you want to update your entities is there where you set the prop you want to change .. like:
[HttpPut]
[ProducesResponseType(typeof(OrderDTO), 200)]
[ProducesResponseType(400)]
public async Task<ActionResult<bool>> Put([FromBody] OrderDTO value)
{
try
{
if (!ModelState.IsValid) return BadRequest(ModelState);
var orderOnDb = await _orderService.FindAsync(xx => xx.Id == value.Id);
if (orderOnDb == null) return BadRequest(Constants.Error.NOT_FOUND_ON_MONGO);
// SET PROPERTY TO UPDATE (MANUALLY)
orderOnDb.LastUpdateDate = DateTime.Now;
orderOnDb.PaymentMethod = value.PaymentMethod;
orderOnDb.StateHistory = value.StateHistory;
//Save on db
var res = await _orderRepo.UpdateAsync(orderOnDb, orderOnDb.Id);
return res;
}
catch (Exception ex)
{
_logger.LogCritical(ex, ex.Message);
throw ex;
}
}
Hope it helps you!!!
I am new to RxJava and finding it very useful for network and database processing within my Android applications.
I have two use cases that I cannot implement completely in RxJava
Use Case 1
Clear down my target database table Table A
Fetch a list of database records from Table B that contain a key field
For each row retrieved from Table B, call a Remote API and persist all the returned data into Table A
The closest I have managed is this code
final AtomicInteger id = new AtomicInteger(0);
DatabaseController.deleteAll(TableA_DO.class);
DatabaseController.fetchTable_Bs()
.subscribeOn(Schedulers.io())
.toObservable()
.flatMapIterable(b -> b)
.flatMap(b_record -> NetworkController.getTable_A_data(b_record.getKey()))
.flatMap(network -> transformNetwork(id, network, NETWORK_B_MAPPER))
.doOnNext(DatabaseController::persistRealmObjects)
.doOnComplete(onComplete)
.doOnError(onError)
.doAfterTerminate(doAfterTerminate())
.doOnSubscribe(compositeDisposable::add)
.subscribe();
Use Case 2
Clear down my target database table Table X
Clear down my target database table Table Y
Fetch a list of database records from Table Z that contain a key field
For each row retrieved from Table B, call a Remote API and persist some of the returned data into Table X the remainder of the data should be persisted into table Y
I have not managed to create any code for use case 2.
I have a number of questions regarding the use of RxJava for these use cases.
Is it possible to achieve both my use cases in RxJava?
Is it "Best Practice" to combine all these steps into an Rx "Stream"
UPDATE
I ended up with this POC test code which seems to work...
I am not sure if its the optimum solution however My API calls return Single and my database operations return Completable so I feel like this is the best solution for me.
public class UseCaseOneA {
public static void main(final String[] args) {
login()
.andThen(UseCaseOneA.deleteDatabaseTableA())
.andThen(UseCaseOneA.deleteDatabaseTableB())
.andThen(manufactureRecords())
.flatMapIterable(x -> x)
.flatMapSingle(record -> NetworkController.callApi(record.getPrimaryKey()))
.flatMapSingle(z -> transform(z))
.flatMapCompletable(p -> UseCaseOneA.insertDatabaseTableA(p))
.doOnComplete(() -> System.out.println("ON COMPLETE"))
.doFinally(() -> System.out.println("ON FINALLY"))
.subscribe();
}
private static Single<List<PayloadDO>> transform(final List<RemotePayload> payloads) {
return Single.create(new SingleOnSubscribe<List<PayloadDO>>() {
#Override
public void subscribe(final SingleEmitter<List<PayloadDO>> emitter) throws Exception {
System.out.println("transform - " + payloads.size());
final List<PayloadDO> payloadDOs = new ArrayList<>();
for (final RemotePayload remotePayload : payloads) {
payloadDOs.add(new PayloadDO(remotePayload.getPayload()));
}
emitter.onSuccess(payloadDOs);
}
});
}
private static Observable<List<Record>> manufactureRecords() {
final List<Record> records = new ArrayList<>();
records.add(new Record("111-111-111"));
records.add(new Record("222-222-222"));
records.add(new Record("3333-3333-3333"));
records.add(new Record("44-444-44444-44-4"));
records.add(new Record("5555-55-55-5-55-5555-5555"));
return Observable.just(records);
}
private static Completable deleteDatabaseTableA() {
return Completable.create(new CompletableOnSubscribe() {
#Override
public void subscribe(final CompletableEmitter emitter) throws Exception {
System.out.println("deleteDatabaseTableA");
emitter.onComplete();
}
});
}
private static Completable deleteDatabaseTableB() {
return Completable.create(new CompletableOnSubscribe() {
#Override
public void subscribe(final CompletableEmitter emitter) throws Exception {
System.out.println("deleteDatabaseTableB");
emitter.onComplete();
}
});
}
private static Completable insertDatabaseTableA(final List<PayloadDO> payloadDOs) {
return Completable.create(new CompletableOnSubscribe() {
#Override
public void subscribe(final CompletableEmitter emitter) throws Exception {
System.out.println("insertDatabaseTableA - " + payloadDOs);
emitter.onComplete();
}
});
}
private static Completable login() {
return Completable.complete();
}
}
This code doesn't address all my use case requirements. Namely being able to transform the remote payload records into multiple Database record types and insert each type into its own specific target databased table.
I could just call the Remote API twice to get the same remote data items and transform first into one database type then secondly into the second database type, however that seems wasteful.
Is there an operand in RxJava where I can reuse the output from my API calls and transform them into another database type?
You have to index the items yourself in some manner, for example, via external counting:
Observable.defer(() -> {
AtomicInteger counter = new AtomicInteger();
return DatabaseController.fetchTable_Bs()
.subscribeOn(Schedulers.io())
.toObservable()
.flatMapIterable(b -> b)
.doOnNext(item -> {
if (counter.getAndIncrement() == 0) {
// this is the very first item
} else {
// these are the subsequent items
}
});
});
The defer is necessary to isolate the counter to the inner sequence so that repetition still works if necessary.
I am working on a JPA/Jersey web app and want to know if there is a better way to update a record. Currently, I am doing:
#PUT
#Path("update/{id}")
#Produces("application/json")
#Consumes("application/x-www-form-urlencoded")
public Response createDevice(
#PathParam("id") int id,
#FormParam("name") String name,
#FormParam("type") int type
/*MultivaluedMap<String, String> formParams*/
) {
try {
Devices newDevice = entityManager.find(Devices.class, id);
if(name==null){name=newDevice.getName();}
if(type != newDevice.getType()){newDevice.setType(type);}
newDevice.setName(name);
//newDevice.setType(type);
entityManager.merge(newDevice);
return Response.status(201).entity(new ResponseObject("success")).build();
} finally {
entityManager.close();
}
}
This works, but if my Devices table had more fields, I would have to check for equality of ALL fields with the values on the original object to see if they've changed, so that my
entityManager.merge(newDevice);
will only change the values passed in.
Is there a better way to do this?