Jakarta EE Concurrency @ManagedExecutorDefinition

Giriş

Açıklaması şöyle

One of the most commonly used services in the Jakarta Concurrency API is the ManagedExecutorService. It is used to create a thread pool in the Jakarta EE environment to spawn threads in a more manageable way. Although it is pretty much the same as ExecutorService, we employ it in the Java SE environment.

To configure the thread pool, we had a vendor-specific setting. Now it can be defined with just annotation. This is a more standard way of configuring the thread pool.

Örnek

Şöyle yaparız

@Path("concurrency")
@RequestScoped
public class GenericResource {
  @Context
  private UriInfo context;
  @Resource
  private ManagedExecutorService managedExecutor;

  @GET
  @Path("simplejob")
  @Produces(MediaType.TEXT_PLAIN)
  public String getText() {
    manageExecutor.submit(() -> {
      System.out.println("Job running...");
    });
    return "Job Sumitted";
  }
}

Örnek

Şöyle yaparız

import static jakarta.enterprise.concurrent.ContextServiceDefinition.APPLICATION;
import static jakarta.enterprise.concurrent.ContextServiceDefinition.SECURITY;

import jakarta.annotation.Resource;
import jakarta.ejb.Asynchronous;

import jakarta.enterprise.concurrent.ContextServiceDefinition;
import jakarta.enterprise.concurrent.ManagedExecutorDefinition;
import jakarta.enterprise.concurrent.ManagedExecutorService;

import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Named;
import java.time.Duration;
import java.time.LocalDate;
import java.util.concurrent.CompletableFuture;

@Named
@ApplicationScoped
@ManagedExecutorDefinition(
    name = "java:module/concurrent/MyExecutor",
    context = "java:module/concurrent/MyExecutorContext",
    hungTaskThreshold = 120000,
    maxAsync = 5)
@ContextServiceDefinition(
    name = "java:module/concurrent/MyExecutorContext",
    propagated = {SECURITY, APPLICATION})
public class WorkService {
  
  @Resource(name = "java:app/concurrent/MyExecutorService")
  private ManagedExecutorService executor;

  @Asynchronous
  public CompletableFuture<Long> hoursWorked(LocalDate from, LocalDate to) {

    return CompletableFuture.supplyAsync(() -> heavyAPICall(from, to), executor);
  }

  private static long heavyAPICall(LocalDate from, LocalDate to) {

    return Duration.between(from, to).toMillis();
  }
}