CompletableFuture sample (with simple error handling)

CompleteableFutureWithExceptionHandling.java

package com.example;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class CompleteableFutureWithExceptionHandling {

    public static void main(String[] args) {

        ExecutorService es = Executors.newFixedThreadPool(3);
        CompletableFuture.allOf(
                CompletableFuture.runAsync(() -> callService("line1"),es),
                CompletableFuture.runAsync(() -> callService("line2-error"),es)
                        .exceptionally(e -> errorHandle(e)) // add error handling.
                //...
        ).join();
        System.out.println("end");
        es.shutdown();
    }

    private static void callService(String content){
        System.out.println("call " + content + " in " + Thread.currentThread());
        if (content.contains("error")) {
            throw new RuntimeException("fake error");
        }
        try {
            Thread.sleep(1000L);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    private static Void errorHandle(Throwable  e){
        if (e != null) {
            System.out.println("error occured. " + e.getMessage());
        }
        return null;
    }
}