All Questions
Tagged with completable-future java-threads
15 questions
0
votes
1
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70
views
What problems can I have with spawning a set of new threads from Servlet and what alternatives exist?
For simplicity, I will omit some details and try to highlight the main point:
I have a servlet that consumes users' requests, when a user sends a request I need to gather data from many endpoints. One ...
- 1,262
-1
votes
1
answer
102
views
Java Unexpected Async Behavior
Im expecting unexpected behaviour in Java(Java 17, Spring Boot app). This method is for test and Im calling it directly from the main method.
Shouldnt the main thread get blocked at the line of ...
- 1
1
vote
1
answer
274
views
How to use CompletableFuture to execute the threads parallaly without waiting and combine the result?
I have executeGetCapability method which is executed in different threads but these threads runs sequentially..meaning one is completed after the other
@Async("threadPoolCapabilitiesExecutor&...
- 763
1
vote
1
answer
6k
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How does whenComplete() work in a chain of CompletionStages?
I thought I understood whenComplete but I'm not sure now. This question originated in another thread.
The way we work with futures in my company is by chaining them:
CompletionStage<Foo> getFoo()...
- 30.3k
1
vote
0
answers
299
views
Pass transaction context under completableFutures
I have a code that basically does something like this:
private void example() {
DefaultTransactionDefinition def = new DefaultTransactionDefinition();
def.setName("name");
...
0
votes
0
answers
43
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Java: Halt method execution after a certain time
Say I have a method called doSomething, and I call the method like this:
int result = doSomething();
And suppose doSomething() takes 500ms to execute by default. However, I want to halt the execution ...
- 233
0
votes
1
answer
654
views
CompletableFuture.runAsync vs array of CompletableFuture
I found this code in a project:
int threadCount = 10;
CompletableFuture<?>[] futures = new CompletableFuture<?>[threadCount];
for (int i = 0; i < threadCount; i++) {
futures[i] = ...
- 4,683
9
votes
1
answer
9k
views
Collect thrown exceptions from CompletableFuture.allOf() execution
Having following scratch code:
public static void main(String[] args) throws ExecutionException, InterruptedException {
CompletableFuture<Void> process1 = CompletableFuture.runAsync(() -&...
- 2,375
1
vote
2
answers
2k
views
How to perform resource cleanup for CompletableFuture in Java?
I've a piece of code in CompletableFuture that performs retry if there are exceptions else completes the task. I've passed a resource to the Supplier and Consumer to perform the task and want to close ...
- 43
3
votes
2
answers
2k
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Calling ExecutorService.shutdownNow from CompletableFuture
I need to cancel all scheduled but not yet running CompletableFuture tasks when one of already running task throws an exception.
Tried following example but most of the time the main method does not ...
- 5,948
0
votes
2
answers
67
views
Optimize async operation executed by rest for many users
in following code I have asynchronous method which is executed by rest by authenticated user. In this method I execute loop in which is checking periodically cache of new data.
@Async
public ...
- 5,341
2
votes
3
answers
13k
views
CompletableFuture: several tasks
How can I asynchronously execute 20 Runnable tasks(or 1 task 20 times), using 5 CompletableFutures?
That's what I've got:
Runnable task = () -> {
long startTime = System.currentTimeMillis(...
- 83
3
votes
1
answer
924
views
Situational use: Run tasks in ForkJoinPool vs. new Thread
Since I'm trying to understand a few of the new features provided in Java 8, I came upon the following situation:
I wish to implement asynchron method calls into my application (in JavaFX). The idea ...
- 947
0
votes
3
answers
354
views
Using the faster output from 2 threads
I want to work with two threads in my Java program for a tiny part. I need to give the first call to a database and the second call to an API, both calls with same input, and then work with the output ...
- 11
7
votes
1
answer
3k
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How do I use CompletableFuture.supplyAsync together with PriorityBlockingQueue?
I'm trying to add a priority queue to an existing application that uses ThreadPoolExecutor with a LinkedBlockingQueue via CompletableFuture.supplyAsync. The problem is that I can't come up with a ...
- 2,906