My Spring webflux function is as below.
#Transactional
public Mono<ServerResponse> addItems(ServerRequest request) {
return request.bodyToMono(ItemDto.class).flatMap(itemReq -> {
final List<ItemErrorDto> errorDtoList = new ArrayList<>();
return saveItem(itemReq, errorDtoList);
});
}
private Mono<ServerResponse> saveItem(ItemDto itemReq,
final List<ItemErrorDto> errorDtoList, Billing billing) {
return Flux.fromIterable(itemReq.getItems())
.doOnNext((item) -> updateQty(item, errorDtoList)).collectList()
.zipWhen((updateResponse) -> saveItem(itemReq, errorDtoList))
.flatMap(updatedQtyResponse -> {
return ok().bodyValue(errorDtoList);
});
}
private void updateQty(final Item item,
final List<ItemQtyErrorDto> errorDtoList) {
if (item.getType() > 1) {
return;
}
inRepository.retrieveQty(item.getId())
.flatMap(qty -> {
Mono<Integer> mono = null;
// .... some if else here to create Mono ...Basically to call some repository query
if (qty > 1) {
mono = inRepository.reduceQty(item.getQty());
} else {
mono = inventoryRepository.increaseQty(item.getQty());
}
return mono.doOnNext((updatedCount) -> {
if (updatedCount == 0) {
ItemQtyErrorDto errorDto = new ItemQtyErrorDto();
errorDto.setQty(item.getQty());
errorDtoList.add(errorDto);
}
}).thenReturn(item.getInventoryId());
}).switchIfEmpty(Mono.defer(() -> {
ItemQtyErrorDto errorDto = new ItemQtyErrorDto();
errorDto.setQty(item.getQty());
errorDtoList.add(errorDto);
return Mono.just(item.getId());
})).subscribe();
}
private Mono<Long> saveBillingItem(ItemDto dto,
final List<ItemQtyErrorDto> errorDtoList) {
.... Logic here ,,, Execute queries .... Update ....
}
Here, saveItem method gets invoked even before the FluxIterable gets completed. But, I need FluxIterable to be completed and then saveItem based on the FluxIterable response.
Related
I just created a simple web API using .NetCore 2.2 and Entity Framework.
I added a bit of security, by passing in a userID to each controller that the user accesses.
But I noticed that it starts getting messy when I have to add the userID to every controller in my app and the run my user check to make sure the user can access that content.
Below you'll see an example of what I mean.
I'm wondering, is there a way to add it once and then have every controller check for it?
Thanks!
[Route("api/[controller]")]
[ApiController]
public class EngineController : ControllerBase
{
private readonly engineMaker_Context _context;
public EngineController(engineMaker_Context context)
{
_context = context;
}
// GET: api/Engine
[HttpGet("{userID}")]
public async Task<ActionResult<IEnumerable<Engine>>> GetEngine(string userID)
{
if(!CanAccessContent(userID))
{
return Unauthorized();
}
return await _context.Engine.ToListAsync();
}
// GET: api/Engine/123/5
[HttpGet("{userID}/{id}")]
public async Task<ActionResult<Engine>> GetEngine(string userID, string id)
{
if(!CanAccessContent(userID))
{
return Unauthorized();
}
var engine = await _context.Engine.FindAsync(id);
if (engine == null)
{
return NotFound();
}
return engine;
}
// PUT: api/Engine/123/5
[HttpPut("{userID}/{id}")]
public async Task<IActionResult> PutEngine(string userID, string id, Engine engine)
{
if(!CanAccessContent(userID))
{
return Unauthorized();
}
if (id != engine.ObjectId)
{
return BadRequest();
}
_context.Entry(engine).State = EntityState.Modified;
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!EngineExists(id))
{
return NotFound();
}
else
{
throw;
}
}
return NoContent();
}
private bool CanAccessContent(string userID)
{
return _context.AllowedUsers.Any(e => e.UserId == userID);
}
}
You could try IAsyncAuthorizationFilter to check the userID.
IAsyncAuthorizationFilter
public class UserIdFilter : IAsyncAuthorizationFilter
{
public Task OnAuthorizationAsync(AuthorizationFilterContext context)
{
var dbContext = context.HttpContext.RequestServices.GetRequiredService<ApplicationDbContext>();
var userId = context.RouteData.Values["userID"] as string;
if (!dbContext.Users.Any(u => u.Email == userId))
{
context.Result = new UnauthorizedResult();
}
return Task.CompletedTask;
}
}
Regiter UserIdFilter for all action.
services.AddMvc(options =>
{
options.Filters.Add(typeof(UserIdFilter));
})
.SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
like this:
spring:
cloud:
gateway:
routes:
- id: static-file
uri: file:///data/pub/
predicates:
- Path=/file/**
Does it support?
I want to replace ResourceHandlerRegistry.addResourceHandler in this way.
My implementation is like this:
#Component
public class GlobalFileRoutingFilter implements GlobalFilter, Ordered {
private static final Log log = LogFactory.getLog(GlobalFileRoutingFilter.class);
private final DispatcherHandler dispatcherHandler;
public GlobalFileRoutingFilter(DispatcherHandler dispatcherHandler) {
this.dispatcherHandler = dispatcherHandler;
}
#Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE;
}
#Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
Route route = (Route)exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
if (route == null) {
return chain.filter(exchange);
} else {
log.trace("GlobalFileRoutingFilter start");
URI routeUri = route.getUri();
String scheme = routeUri.getScheme();
if (isAlreadyRouted(exchange) || !"file".equals(scheme)) {
return chain.filter(exchange);
}
setAlreadyRouted(exchange);
ServerHttpRequest request = exchange.getRequest();
ServerHttpResponse response = exchange.getResponse();
String filePath = routeUri.getPath() + File.separator + request.getURI().getPath();
if (log.isTraceEnabled()) {
log.trace("Reading from file: "+filePath);
}
if ("HEAD".equalsIgnoreCase(request.getMethod().toString())) {
response.getHeaders().set(HttpHeaders.ACCEPT_RANGES, "none");
} else {
File file = new File(filePath);
if (!file.exists()) {
response.setStatusCode(HttpStatus.NOT_FOUND);
} else {
DataBuffer dataBuffer = response.bufferFactory().allocateBuffer();
try {
dataBuffer.write(IOUtils.toByteArray(new FileInputStream(file)));
} catch (IOException e) {
if (log.isErrorEnabled()) {
log.error(e);
}
}
return response.writeAndFlushWith(Flux.just(Flux.just(dataBuffer)));
}
}
return Mono.empty();
}
}
}
Project Reactor has this factory method for creating a push/pull Producer<T>.
http://projectreactor.io/docs/core/release/reference/#_hybrid_push_pull_model
Is there any such thing in RxJava-2?
If not, what would be the recommended way (without actually implemementing reactive specs interfaces from scratch) to create such beast that can handle the push/pull model?
EDIT: as requested I am giving an example of the API I am trying to use...
private static class API
{
CompletableFuture<Void> getT(Consumer<Object> consumer) {}
}
private static class Callback implements Consumer<Object>
{
private API api;
public Callback(API api) { this api = api; }
#Override
public void accept(Object o)
{
//do stuff with o
//...
//request for another o
api.getT(this);
}
}
public void example()
{
API api = new API();
api.getT(new Callback(api)).join();
}
So it's call back based, which will get one item and from within you can request for another one. the completable future flags no more items.
Here is an example of a custom Flowable that turns this particular API into an RxJava source. Note however that in general, the API peculiarities in general may not be possible to capture with a single reactive bridge design:
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.*;
import java.util.function.*;
import org.reactivestreams.*;
import io.reactivex.Flowable;
import io.reactivex.internal.subscriptions.EmptySubscription;
import io.reactivex.internal.util.BackpressureHelper;
public final class SomeAsyncApiBridge<T> extends Flowable<T> {
final Function<? super Consumer<? super T>,
? extends CompletableFuture<Void>> apiInvoker;
final AtomicBoolean once;
public SomeAsyncApiBridge(Function<? super Consumer<? super T>,
? extends CompletableFuture<Void>> apiInvoker) {
this.apiInvoker = apiInvoker;
this.once = new AtomicBoolean();
}
#Override
protected void subscribeActual(Subscriber<? super T> s) {
if (once.compareAndSet(false, true)) {
SomeAsyncApiBridgeSubscription<T> parent =
new SomeAsyncApiBridgeSubscription<>(s, apiInvoker);
s.onSubscribe(parent);
parent.moveNext();
} else {
EmptySubscription.error(new IllegalStateException(
"Only one Subscriber allowed"), s);
}
}
static final class SomeAsyncApiBridgeSubscription<T>
extends AtomicInteger
implements Subscription, Consumer<T>, BiConsumer<Void, Throwable> {
/** */
private static final long serialVersionUID = 1270592169808316333L;
final Subscriber<? super T> downstream;
final Function<? super Consumer<? super T>,
? extends CompletableFuture<Void>> apiInvoker;
final AtomicInteger wip;
final AtomicLong requested;
final AtomicReference<CompletableFuture<Void>> task;
static final CompletableFuture<Void> TASK_CANCELLED =
CompletableFuture.completedFuture(null);
volatile T item;
volatile boolean done;
Throwable error;
volatile boolean cancelled;
long emitted;
SomeAsyncApiBridgeSubscription(
Subscriber<? super T> downstream,
Function<? super Consumer<? super T>,
? extends CompletableFuture<Void>> apiInvoker) {
this.downstream = downstream;
this.apiInvoker = apiInvoker;
this.requested = new AtomicLong();
this.wip = new AtomicInteger();
this.task = new AtomicReference<>();
}
#Override
public void request(long n) {
BackpressureHelper.add(requested, n);
drain();
}
#Override
public void cancel() {
cancelled = true;
CompletableFuture<Void> curr = task.getAndSet(TASK_CANCELLED);
if (curr != null && curr != TASK_CANCELLED) {
curr.cancel(true);
}
if (getAndIncrement() == 0) {
item = null;
}
}
void moveNext() {
if (wip.getAndIncrement() == 0) {
do {
CompletableFuture<Void> curr = task.get();
if (curr == TASK_CANCELLED) {
return;
}
CompletableFuture<Void> f = apiInvoker.apply(this);
if (task.compareAndSet(curr, f)) {
f.whenComplete(this);
} else {
curr = task.get();
if (curr == TASK_CANCELLED) {
f.cancel(true);
return;
}
}
} while (wip.decrementAndGet() != 0);
}
}
#Override
public void accept(Void t, Throwable u) {
if (u != null) {
error = u;
task.lazySet(TASK_CANCELLED);
}
done = true;
drain();
}
#Override
public void accept(T t) {
item = t;
drain();
}
void drain() {
if (getAndIncrement() != 0) {
return;
}
int missed = 1;
long e = emitted;
for (;;) {
for (;;) {
if (cancelled) {
item = null;
return;
}
boolean d = done;
T v = item;
boolean empty = v == null;
if (d && empty) {
Throwable ex = error;
if (ex == null) {
downstream.onComplete();
} else {
downstream.onError(ex);
}
return;
}
if (empty || e == requested.get()) {
break;
}
item = null;
downstream.onNext(v);
e++;
moveNext();
}
emitted = e;
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
}
}
Test and example source:
import java.util.concurrent.*;
import java.util.function.Consumer;
import org.junit.Test;
public class SomeAsyncApiBridgeTest {
static final class AsyncRange {
final int max;
int index;
public AsyncRange(int start, int count) {
this.index = start;
this.max = start + count;
}
public CompletableFuture<Void> next(Consumer<? super Integer> consumer) {
int i = index;
if (i == max) {
return CompletableFuture.completedFuture(null);
}
index = i + 1;
CompletableFuture<Void> cf = CompletableFuture
.runAsync(() -> consumer.accept(i));
CompletableFuture<Void> cancel = new CompletableFuture<Void>() {
#Override
public boolean cancel(boolean mayInterruptIfRunning) {
cf.cancel(mayInterruptIfRunning);
return super.cancel(mayInterruptIfRunning);
}
};
return cancel;
}
}
#Test
public void simple() {
AsyncRange r = new AsyncRange(1, 10);
new SomeAsyncApiBridge<Integer>(
consumer -> r.next(consumer)
)
.test()
.awaitDone(500, TimeUnit.SECONDS)
.assertResult(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
}
}
This is something that looks that is working using Reactor's Flux.create(). I changed the API a bit.
public class FlowableGenerate4
{
private static class API
{
private ExecutorService es = Executors.newFixedThreadPool(1);
private CompletableFuture<Void> done = new CompletableFuture<>();
private AtomicInteger stopCounter = new AtomicInteger(10);
public boolean isDone()
{
return done.isDone();
}
public CompletableFuture<Void> getT(Consumer<Object> consumer)
{
es.submit(() -> {
try {
Thread.sleep(100);
} catch (Exception e) {
}
if (stopCounter.decrementAndGet() < 0)
done.complete(null);
else
consumer.accept(new Object());
});
return done;
}
}
private static class Callback implements Consumer<Object>
{
private API api;
private FluxSink<Object> sink;
public Callback(API api, FluxSink<Object> sink)
{
this.api = api;
this.sink = sink;
}
#Override
public void accept(Object o)
{
sink.next(o);
if (sink.requestedFromDownstream() > 0 && !api.isDone())
api.getT(this);
else
sink.currentContext().<AtomicBoolean>get("inProgress")
.set(false);
}
}
private Publisher<Object> reactorPublisher()
{
API api = new API();
return
Flux.create(sink -> {
sink.onRequest(n -> {
//if it's in progress already, do nothing
//I understand that onRequest() can be called asynchronously
//regardless if the previous call demand has been satisfied or not
if (!sink.currentContext().<AtomicBoolean>get("inProgress")
.compareAndSet(false, true))
return;
//else kick off calls to API
api.getT(new Callback(api, sink))
.whenComplete((o, t) -> {
if (t != null)
sink.error(t);
else
sink.complete();
});
});
}).subscriberContext(
Context.empty().put("inProgress", new AtomicBoolean(false)));
}
#Test
public void test()
{
Flowable.fromPublisher(reactorPublisher())
.skip(5)
.take(10)
.blockingSubscribe(
i -> System.out.println("onNext()"),
Throwable::printStackTrace,
() -> System.out.println("onComplete()")
);
}
}
Scenario: I have a stream of data I am reading from the database. What I would like to do is read a chunk of data, process it and stream it using rx-java 2. But while I am processing and streaming it I would like to load the next chunk of data on a separate thread (pre-pull the next chunk).
I have tried:
Flowable.generate(...)
.subscribeOn(Schedulers.io())
.observeOn(Schedulers.computation())
.map(...)
.subscribe(...)
Unfortunately this causes the generate method to continually run on an io thread. I just want one pre-pull. I have tried using buffer, but that really just ends up creating lists of chunks.
So basically while I am streaming the current chunk on a separate thread I want to read the next chunk and have it ready.
Not sure if this is possible. I need to use generate because there is no concept of when the data will end.
I have tried using subscribe(new FlowableSubscriber(){...}) using Subscription::request but that did not seem to work.
There are no standard operators in RxJava that would have this type of request-response pattern. You'd need a custom observeOn that requests before it sends the current item to its downstream.
import java.util.concurrent.atomic.*;
import org.junit.Test;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.Scheduler.Worker;
import io.reactivex.internal.util.BackpressureHelper;
import io.reactivex.schedulers.Schedulers;
public class LockstepObserveOnTest {
#Test
public void test() {
Flowable.generate(() -> 0, (s, e) -> {
System.out.println("Generating " + s);
Thread.sleep(500);
e.onNext(s);
return s + 1;
})
.subscribeOn(Schedulers.io())
.compose(new LockstepObserveOn<>(Schedulers.computation()))
.map(v -> {
Thread.sleep(250);
System.out.println("Processing " + v);
Thread.sleep(250);
return v;
})
.take(50)
.blockingSubscribe();
}
static final class LockstepObserveOn<T> extends Flowable<T>
implements FlowableTransformer<T, T> {
final Flowable<T> source;
final Scheduler scheduler;
LockstepObserveOn(Scheduler scheduler) {
this(null, scheduler);
}
LockstepObserveOn(Flowable<T> source, Scheduler scheduler) {
this.source = source;
this.scheduler = scheduler;
}
#Override
protected void subscribeActual(Subscriber<? super T> subscriber) {
source.subscribe(new LockstepObserveOnSubscriber<>(
subscriber, scheduler.createWorker()));
}
#Override
public Publisher<T> apply(Flowable<T> upstream) {
return new LockstepObserveOn<>(upstream, scheduler);
}
static final class LockstepObserveOnSubscriber<T>
implements FlowableSubscriber<T>, Subscription, Runnable {
final Subscriber<? super T> actual;
final Worker worker;
final AtomicReference<T> item;
final AtomicLong requested;
final AtomicInteger wip;
Subscription upstream;
volatile boolean cancelled;
volatile boolean done;
Throwable error;
long emitted;
LockstepObserveOnSubscriber(Subscriber<? super T> actual, Worker worker) {
this.actual = actual;
this.worker = worker;
this.item = new AtomicReference<>();
this.requested = new AtomicLong();
this.wip = new AtomicInteger();
}
#Override
public void onSubscribe(Subscription s) {
upstream = s;
actual.onSubscribe(this);
s.request(1);
}
#Override
public void onNext(T t) {
item.lazySet(t);
schedule();
}
#Override
public void onError(Throwable t) {
error = t;
done = true;
schedule();
}
#Override
public void onComplete() {
done = true;
schedule();
}
#Override
public void request(long n) {
BackpressureHelper.add(requested, n);
schedule();
}
#Override
public void cancel() {
cancelled = true;
upstream.cancel();
worker.dispose();
if (wip.getAndIncrement() == 0) {
item.lazySet(null);
}
}
void schedule() {
if (wip.getAndIncrement() == 0) {
worker.schedule(this);
}
}
#Override
public void run() {
int missed = 1;
long e = emitted;
for (;;) {
long r = requested.get();
while (e != r) {
if (cancelled) {
item.lazySet(null);
return;
}
boolean d = done;
T v = item.get();
boolean empty = v == null;
if (d && empty) {
Throwable ex = error;
if (ex == null) {
actual.onComplete();
} else {
actual.onError(ex);
}
worker.dispose();
return;
}
if (empty) {
break;
}
item.lazySet(null);
upstream.request(1);
actual.onNext(v);
e++;
}
if (e == r) {
if (cancelled) {
item.lazySet(null);
return;
}
if (done && item.get() == null) {
Throwable ex = error;
if (ex == null) {
actual.onComplete();
} else {
actual.onError(ex);
}
worker.dispose();
return;
}
}
emitted = e;
missed = wip.addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
}
}
}
The AutoCompleteTextField seems to work exactly as intended until I start backspacing in the TextField. I am not sure what the difference is, but if I type in something like "123 M" then I get values that start with "123 M". If I backspace and delete the M leaving "123 " in the field, the list changes, but it does not scroll to the top of the list.
I should note that everything works fine on the simulator and that I am experiencing this behavior when running a debug build on my iPhone.
EDIT: So this does not only seem to happen when backspacing. This image shows the results I have when typing in an address key by key. In any of the pictures where the list isn't viewable or is clipped, I am able to drag down on the list to get it to then display properly. I have not tried this on an Android device.
EDIT2:
public class CodenameOneTest {
private Form current;
private Resources theme;
private WaitingClass w;
private String[] properties = {"1 MAIN STREET", "123 E MAIN STREET", "12 EASTER ROAD", "24 MAIN STREET"};
public void init(Object context) {
theme = UIManager.initFirstTheme("/theme");
// Enable Toolbar on all Forms by default
Toolbar.setGlobalToolbar(true);
}
public void start() {
if(current != null) {
current.show();
return;
}
Form form = new Form("AutoCompleteTextField");
form.setLayout(new BorderLayout());
final DefaultListModel<String> options = new DefaultListModel<>();
AutoCompleteTextField ac = new AutoCompleteTextField(options) {
protected boolean filter(String text) {
if(text.length() == 0) {
options.removeAll();
return false;
}
String[] l = searchLocations(text);
if(l == null || l.length == 0) {
return false;
}
options.removeAll();
for(String s : l) {
options.addItem(s);
}
return true;
};
};
Container container = new Container(BoxLayout.y());
container.setScrollableY(true); // If you comment this out then the field works fine
container.add(ac);
form.addComponent(BorderLayout.CENTER, container);
form.show();
}
String[] searchLocations(String text) {
try {
if(text.length() > 0) {
if(w != null) {
w.actionPerformed(null);
}
w = new WaitingClass();
String[] properties = getProperties(text);
if(Display.getInstance().isEdt()) {
Display.getInstance().invokeAndBlock(w);
}
else {
w.run();
}
return properties;
}
}
catch(Exception e) {
Log.e(e);
}
return null;
}
private String[] getProperties(String text) {
List<String> returnList = new ArrayList<>();
List<String> propertyList = Arrays.asList(properties);
for(String property : propertyList) {
if(property.startsWith(text)) {
returnList.add(property);
}
}
w.actionPerformed(null);
return returnList.toArray(new String[returnList.size()]);
}
class WaitingClass implements Runnable, ActionListener<ActionEvent> {
private boolean finishedWaiting;
public void run() {
while(!finishedWaiting) {
try {
Thread.sleep(30);
}
catch(InterruptedException ex) {
ex.printStackTrace();
}
}
}
public void actionPerformed(ActionEvent e) {
finishedWaiting = true;
return;
}
}
public void stop() {
current = Display.getInstance().getCurrent();
if(current instanceof Dialog) {
((Dialog)current).dispose();
current = Display.getInstance().getCurrent();
}
}
public void destroy() {
}
}
I used this code on an iPhone 4s:
public void start() {
if(current != null){
current.show();
return;
}
Form hi = new Form("AutoComplete", new BorderLayout());
if(apiKey == null) {
hi.add(new SpanLabel("This demo requires a valid google API key to be set in the constant apiKey, "
+ "you can get this key for the webservice (not the native key) by following the instructions here: "
+ "https://developers.google.com/places/web-service/get-api-key"));
hi.getToolbar().addCommandToRightBar("Get Key", null, e -> Display.getInstance().execute("https://developers.google.com/places/web-service/get-api-key"));
hi.show();
return;
}
Container box = new Container(new BoxLayout(BoxLayout.Y_AXIS));
box.setScrollableY(true);
for(int iter = 0 ; iter < 30 ; iter++) {
box.add(createAutoComplete());
}
hi.add(BorderLayout.CENTER, box);
hi.show();
}
private AutoCompleteTextField createAutoComplete() {
final DefaultListModel<String> options = new DefaultListModel<>();
AutoCompleteTextField ac = new AutoCompleteTextField(options) {
#Override
protected boolean filter(String text) {
if(text.length() == 0) {
return false;
}
String[] l = searchLocations(text);
if(l == null || l.length == 0) {
return false;
}
options.removeAll();
for(String s : l) {
options.addItem(s);
}
return true;
}
};
ac.setMinimumElementsShownInPopup(5);
return ac;
}
String[] searchLocations(String text) {
try {
if(text.length() > 0) {
ConnectionRequest r = new ConnectionRequest();
r.setPost(false);
r.setUrl("https://maps.googleapis.com/maps/api/place/autocomplete/json");
r.addArgument("key", apiKey);
r.addArgument("input", text);
NetworkManager.getInstance().addToQueueAndWait(r);
Map<String,Object> result = new JSONParser().parseJSON(new InputStreamReader(new ByteArrayInputStream(r.getResponseData()), "UTF-8"));
String[] res = Result.fromContent(result).getAsStringArray("//description");
return res;
}
} catch(Exception err) {
Log.e(err);
}
return null;
}
I was able to create this issue but not the issue you describe.