I am using paging library, inside my viewmodel value of LiveData> liveData;
is updating but obeserver in the activity is not able to observe the change after 1st time . and LivePagedListBuilder returns only LiveData so I am not able to replace it with mutableLivedata .
public class RecipeListViewModel extends AndroidViewModel {
public LiveData<PagedList<RecipeListPojo>> liveData;
private Context context;
public RecipeListViewModel(#NonNull Application application) {
super(application);
context=application.getApplicationContext();
}
public LiveData<PagedList<RecipeListPojo>> init(RecipeDao recipeDao,RecipeFrom recipeFrom,String orderBy) {
String query=ChefDatabase.getInstance(context).recipeListQueryBuilder(recipeFrom);
query=query +ORDER_BY+orderBy;
SimpleSQLiteQuery simpleSQLiteQuery = new SimpleSQLiteQuery(query);
try {
liveData = new LivePagedListBuilder(recipeDao.getAllRecipesList(simpleSQLiteQuery), 6).build();
} catch (Exception e) {
e.printStackTrace();
}
return liveData;
}
Related
I tried this:
void onShutdown(#Observes final ShutdownEvent event) throws InterruptedException {
log.infof("ShutdownEvent received, waiting for %s seconds before shutting down", shutdownWaitSeconds);
TimeUnit.SECONDS.sleep(shutdownWaitSeconds);
log.info("Continue shutting down");
}
But after receiving ShutdownEvent Quarkus already responds with 503 to http requests. Looks like this could be done with ShutdownListener in preShutdown method. I have implemented this listener but it does not get called yet. How do I register ShutdownListener?
Use case here is OpenShift sending requests to terminating pod.
Option 1: Create Quarkus extension
Instructions are here. ShutdownController is my own class implementing ShutdownListener where I have a sleep in preShutdown method.
class ShutdownControllerProcessor {
#BuildStep
FeatureBuildItem feature() {
return new FeatureBuildItem("shutdown-controller");
}
#BuildStep
ShutdownListenerBuildItem shutdownListener() {
// Called at build time. Default constructor will be called at runtime.
// Getting MethodNotFoundException when calling default constructor here.
return new ShutdownListenerBuildItem(new ShutdownController(10));
}
}
Option 2: Modify ShutdownRecorder private static final field
New shutdown listener can be added using reflection. This is a bit ugly solution.
registerIfNeeded() need to be called after Quarkus startup, for example with timer 1 second after #PostConstruct.
#ApplicationScoped
public class ListenerRegisterer {
public void registerIfNeeded() {
try {
tryToRegister();
} catch (NoSuchFieldException | IllegalAccessException e) {
throw new IllegalStateException(e);
}
}
private void tryToRegister() throws NoSuchFieldException, IllegalAccessException {
final var field = ShutdownRecorder.class.getDeclaredField("shutdownListeners");
field.setAccessible(true);
final var listeners = (List<ShutdownListener>) field.get(null);
if (listeners != null && !listeners.toString().contains("ShutdownController")) {
listeners.add(new ShutdownController(10));
setFinalStatic(field, listeners);
}
}
private static void setFinalStatic(final Field field, final Object newValue) throws NoSuchFieldException, IllegalAccessException {
field.setAccessible(true);
final var modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
field.set(null, newValue);
}
}
I am setting up java based graphQl App and find graphql-java-tools really convenient the problem though while itis pretty straight forward
With graphql-java to make field resolvers Async I couldn't Find a way to do it using graphql-java-tools
I tried
#Bean
public ExecutionStrategy executionStrategy() {
return new AsyncExecutionStrategy();
}
Here resolvers I use in order to test
#Component
public class VideoResolver implements GraphQLResolver<Video> {
public Episode getEpisode(Video video){
Episode result = new Episode();
result.setTitle("episodeTitle");
result.setUuid("EpisodeUuid");
result.setBrand("episodeBrand");
try {
Thread.sleep(2000L);
System.out.println(Thread.currentThread().getName());
} catch (InterruptedException e) {
e.printStackTrace();
}
return result;
}
public List<Images> getImages(Video video){
Images image = new Images();
image.setFileName("Image FileName1");
List<Images> imageList = new ArrayList<>();
imageList.add(image);
try {
Thread.sleep(2000L);
System.out.println(Thread.currentThread().getName());
} catch (InterruptedException e) {
System.out.println("Exxxxxxxxxx");
}
return imageList;
}
}
Was assuming this should run in about 2 seconds and print two different streams but no it takes 4
and print it is all in one same stream
I have spent day after day trying to find a solution for my problem with Transactional methods. The logic is like this:
Controller receive request, call queueService, put it in a PriorityBlockingQueue and another thread process the data (find cards, update status,assign to current game, return data)
Controller:
#RequestMapping("/queue")
public DeferredResult<List<Card>> queueRequest(#Params...){
queueService.put(result, size, terminal, time)
result.onCompletion(() -> assignmentService.assignCards(result, game,room, cliente));
}
QueueService:
#Service
public class QueueService {
private BlockingQueue<RequestQueue> queue = new PriorityBlockingQueue<>();
#Autowired
GameRepository gameRepository;
#Autowired
TerminalRepository terminalRepository;
#Autowired
RoomRpository roomRepository;
private long requestId = 0;
public void put(DeferredResult<List<Card>> result, int size, String client, LocalDateTime time_order){
requestId++;
--ommited code(find Entity: game, terminal, room)
try {
RequestQueue request= new RequestCola(requestId, size, terminal,time_order, result);
queue.put(request);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
CardService:
#Transactional
public class CardService {
#Autowired
EntityManager em;
#Autowired
CardRepository cardRepository;
#Autowired
AsignService asignacionService;
public List<Cards> processRequest(int size, BigDecimal value)
{
List<Card> carton_query = em.createNativeQuery("{call cards_available(?,?,?)}",
Card.class)
.setParameter(1, false)
.setParameter(2, value)
.setParameter(3, size).getResultList();
List<String> ids = new ArrayList<String>();
carton_query.forEach(action -> ids.add(action.getId_card()));
String update_query = "UPDATE card SET available=true WHERE id_card IN :ids";
em.createNativeQuery(update_query).setParameter("ids", ids).executeUpdate();
return card_query;
}
QueueExecutor (Consumer)
#Component
public class QueueExecute {
#Autowired
QueueService queueRequest;
#Autowired
AsignService asignService;
#Autowired
CardService cardService;
#PostConstruct
public void init(){
new Thread(this::execute).start();
}
private void execute(){
while (true){
try {
RequestQueue request;
request = queueRequest.take();
if(request != null) {
List<Card> cards = cardService.processRequest(request.getSize(), new BigDecimal("1.0"));
request.getCards().setResult((ArrayList<Card>) cards);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
AssignService:
#Transactional
public void assignCards(DeferredResult<List<Card>> cards, Game game, Room room, Terminal terminal)
{
game = em.merge(game);
room = em.merge(room);
terminal = em.merge(terminal);
Order order = new Order();
LocalDateTime datetime = LocalDateTime.now();
BigDecimal total = new BigDecimal("0.0");
order.setTime(datetime)
order.setRoom(room);
order.setGame(game);
order.setId_terminal(terminal);
for(Card card: (List<Card>)cards.getResult()) {
card= em.merge(card)
--> System.out.println("CARD STATUS" + card.getStatus());
// This shows the OLD value of the Card (not updated)
card.setOrder(order);
order.getOrder().add(card);
}
game.setOrder(order);
//gameRepository.save(game)
}
With this code, it does not save new Card status on DB but Game, Terminal and Room saves ok on DB (more or less...). If I remove the assignService, CardService saves the new status on DB correctly.
I have tried to flush manually, save with repo and so on... but the result is almost the same. Could anybody help me?
I think I found a solution (probably not the optimum), but it's more related to the logic of my program.
One of the main problems was the update of Card status property, because it was not reflected on the entity object. When the assignOrder method is called it received the old Card value because it's not possible to share information within Threads/Transactions (as far I know). This is normal within transactions because em.executeUpdate() only commits database, so if I want to get the updated entity I need to refresh it with em.refresh(Entity), but this caused performance to go down.
At the end I changed the logic: first create Orders (transactional) and then assign cards to the orders (transactional). This way works correctly.
I'm using Paging Library to load data from network using ItemKeyedDataSource. After fetching items user can edit them, this updates are done inside in Memory cache (no database like Room is used).
Now since the PagedList itself cannot be updated (discussed here) I have to recreate PagedList and pass it to the PagedListAdapter.
The update itself is no problem but after updating the recyclerView with the new PagedList, the list jumps to the beginning of the list destroying previous scroll position. Is there anyway to update PagedList while keeping scroll position (like how it works with Room)?
DataSource is implemented this way:
public class MentionKeyedDataSource extends ItemKeyedDataSource<Long, Mention> {
private Repository repository;
...
private List<Mention> cachedItems;
public MentionKeyedDataSource(Repository repository, ..., List<Mention> cachedItems){
super();
this.repository = repository;
this.teamId = teamId;
this.inboxId = inboxId;
this.filter = filter;
this.cachedItems = new ArrayList<>(cachedItems);
}
#Override
public void loadInitial(#NonNull LoadInitialParams<Long> params, final #NonNull ItemKeyedDataSource.LoadInitialCallback<Mention> callback) {
Observable.just(cachedItems)
.filter(() -> return cachedItems != null && !cachedItems.isEmpty())
.switchIfEmpty(repository.getItems(..., params.requestedLoadSize).map(...))
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(response -> callback.onResult(response.data.list));
}
#Override
public void loadAfter(#NonNull LoadParams<Long> params, final #NonNull ItemKeyedDataSource.LoadCallback<Mention> callback) {
repository.getOlderItems(..., params.key, params.requestedLoadSize)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(response -> callback.onResult(response.data.list));
}
#Override
public void loadBefore(#NonNull LoadParams<Long> params, final #NonNull ItemKeyedDataSource.LoadCallback<Mention> callback) {
repository.getNewerItems(..., params.key, params.requestedLoadSize)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(response -> callback.onResult(response.data.list));
}
#NonNull
#Override
public Long getKey(#NonNull Mention item) {
return item.id;
}
}
The PagedList created like this:
PagedList.Config config = new PagedList.Config.Builder()
.setPageSize(PAGE_SIZE)
.setInitialLoadSizeHint(preFetchedItems != null && !preFetchedItems.isEmpty()
? preFetchedItems.size()
: PAGE_SIZE * 2
).build();
pagedMentionsList = new PagedList.Builder<>(new MentionKeyedDataSource(mRepository, team.id, inbox.id, mCurrentFilter, preFetchedItems)
, config)
.setFetchExecutor(ApplicationThreadPool.getBackgroundThreadExecutor())
.setNotifyExecutor(ApplicationThreadPool.getUIThreadExecutor())
.build();
The PagedListAdapter is created like this:
public class ItemAdapter extends PagedListAdapter<Item, ItemAdapter.ItemHolder> { //Adapter from google guide, Nothing special here.. }
mAdapter = new ItemAdapter(new DiffUtil.ItemCallback<Mention>() {
#Override
public boolean areItemsTheSame(Item oldItem, Item newItem) {
return oldItem.id == newItem.id;
}
#Override
public boolean areContentsTheSame(Item oldItem, Item newItem) {
return oldItem.equals(newItem);
}
});
, and updated like this:
mAdapter.submitList(pagedList);
P.S: If there is a better way to update list items without using Room please share.
All you need to do is to invalidate current DataSource each time you update your data.
What I would do:
move networking logic from MentionKeyedDataSource to new class that extends PagedList.BoundaryCallback and set it when building your PagedList.
move all you data to some DataProvider that holds all your downloaded data and has reference to DataSource. Each time data is updated in DataProvider invalidate current DataSource
Something like that maybe
val dataProvider = PagedDataProvider()
val dataSourceFactory = InMemoryDataSourceFactory(dataProvider = dataProvider)
where
class PagedDataProvider : DataProvider<Int, DataRow> {
private val dataCache = mutableMapOf<Int, List<DataRow>>()
override val sourceLiveData = MutableLiveData<DataSource<Int, DataRow>>()
//implement data add/remove/update here
//and after each modification call
//sourceLiveData.value?.invalidate()
}
and
class InMemoryDataSourceFactory<Key, Value>(
private val dataProvider: DataProvider<Key, Value>
) : DataSource.Factory<Key, Value>() {
override fun create(): DataSource<Key, Value> {
val source = InMemoryDataSource(dataProvider = dataProvider)
dataProvider.sourceLiveData.postValue(source)
return source
}
}
This approach is very similar to what Room does - every time table row is updated - current DataSource is invalidated and DataSourceFactory creates new data source.
You can modify directly in your adapter if you called currentList like that
class ItemsAdapter(): PagedListAdapter<Item, ItemsAdapter.ViewHolder(ITEMS_COMPARATOR) {
...
fun changeItem(position: Int,newData:String) {
currentList?.get(position)?.data = newData
notifyItemChanged(position)
}
}
So I've been working on an extremely simple website over the past 2 days, but I figured it would be neat to somehow link the website with a Discord bot. For the Discord bot part, I've been using the JDA library.
The issue I'm running in to is that I seem to be unable to use the save method. However, the findById and findAll seem to work perfectly fine. The way I have my code setup can be found below.
#Controller
public class IndexController extends ListenerAdapter {
private static boolean botStarted = false;
#Autowired
private NewsPostRepository newsPostRepository;
#GetMapping("/")
public String getIndex(ModelMap map) {
// TODO: add news post images.
NewsPost savedNewsPost = newsPostRepository.save(new NewsPost("Controller", "Posted through controller",
new byte[]{}, new Date(), true));
System.out.println(savedNewsPost);
return "index";
}
#GetMapping("/start")
public String startBot() {
if (!botStarted) {
try {
JDA jda = new JDABuilder(AccountType.BOT)
.setToken("my-token")
.addEventListener(this)
.buildBlocking(); // Blocking vs async
} catch (LoginException e) {
e.printStackTrace();
} catch (RateLimitedException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
botStarted = true;
}
}
return "redirect:/";
}
#Override
public void onMessageReceived(MessageReceivedEvent messageReceivedEvent) {
User author = messageReceivedEvent.getAuthor();
MessageChannel channel = messageReceivedEvent.getChannel();
Message message = messageReceivedEvent.getMessage();
if (!author.isBot()) {
if (message.getContent().startsWith("!news")) {
NewsPost savedNewsPost = newsPostRepository.save(new NewsPost("Discord", "Posted through Discord",
new byte[]{}, new Date(), true));
System.out.println(savedNewsPost);
}
}
}
}
The repository:
public interface NewsPostRepository extends CrudRepository<NewsPost, String> {
}
The weird thing is, that when I go to the index page, the NewsPost saves perfectly fine, and is visible in the database.
When I try to use the Discord bot to add a NewsPost, it returns an object in the same way it would in the method for the index, with an ID that is not null and should be usable to find it in the database, however, this entry is nowhere to be found. No exception appears either. Keep in mind that both of these save() calls are identical.
I've tried to use a service and adding #Transactional but so far nothing has worked.