HttpCallDemo.java

import com.netflix.config.ConfigurationManager;
import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixCommandGroupKey;
import com.netflix.hystrix.HystrixCommandKey;
import com.netflix.hystrix.HystrixCommandProperties;
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;

import java.io.IOException;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class HttpCallDemo {

    public static void main(String... args) throws InterruptedException {
        ConfigurationManager.getConfigInstance().setProperty("hystrix.command.customcommand.execution.isolation.thread.timeoutInMilliseconds", 1000);
        new HttpCallDemo().start();
    }

    private final ThreadPoolExecutor pool = new ThreadPoolExecutor(1, 3, 3, TimeUnit.MINUTES,
            new SynchronousQueue<>(), new ThreadPoolExecutor.CallerRunsPolicy());

    private void start() throws InterruptedException {
        pool.execute(() -> {
            new CustomCommand().execute();
        });
        pool.awaitTermination(5, TimeUnit.SECONDS);
        pool.shutdown();
    }

    private static class CustomCommand extends HystrixCommand<String> {

        private HttpGet request;

        protected CustomCommand() {
            super(Setter
                    .withGroupKey(HystrixCommandGroupKey.Factory.asKey("Demo"))
                    .andCommandPropertiesDefaults(HystrixCommandProperties.Setter()
                            .withExecutionIsolationStrategy(HystrixCommandProperties.ExecutionIsolationStrategy.THREAD))
                    .andCommandKey(HystrixCommandKey.Factory.asKey("customcommand")));
        }

        protected String run() throws Exception {
            System.out.println("Main method runs in " + Thread.currentThread().getName());
            String url = "https://httpbin.org/delay/2";
            HttpClient client = HttpClientBuilder.create() .build();
            this.request = new HttpGet(url);
            String response = "NO RESPONSE";
            try {
                HttpResponse execute = client.execute(request);
                response = IOUtils.toString(execute.getEntity().getContent());
            } catch (IOException e) {
                System.out.println("Exception " + e.getClass().getSimpleName());
            }
            System.out.println("Supplier returned on " + Thread.currentThread().getName());
            System.out.println("Thread" + Thread.currentThread().getName() + " is " + (Thread.currentThread().isInterrupted() ? "interrupted" : "not ainterrupted"));
            return response;
        }
        @Override
        protected String getFallback() {
            System.out.println("Fallback method runs in " + Thread.currentThread().getName());
            System.out.println("Fallback because of " + getExecutionException().getClass().getSimpleName());
            return "Fallback";
        }
    }
}