Topics/Executors/Messaging/task.html - main - anton.buldygin/Graph-Algorithms-Visualizer

Topics/Executors/Messaging/task.html
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antonBuldygin
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25 янв 2023, 13:49
25 янв 2023, 13:49cd4ee6e
<h2>Messaging</h2>
<p>Write a program that simulates a simple message system. Each message has three fields: <code class="language-java">from</code>, <code class="language-java">to</code> and <code class="language-java">text</code>.</p>

<p>The interface <code class="language-java">AsyncMessageSender</code> describes an abstraction that can send messages and stop its work.</p>

<pre><code class="language-java">interface AsyncMessageSender {
    public void sendMessages(Message[] messages);
    public void stop();
}</code></pre>

<p>The class <code class="language-java">AsyncMessageSenderImpl</code> implements this interface and repeats each message several times (according to a variable).</p>

<p>Complete this class:</p>

<ul>
	<li>it should use <code class="language-java">ExecutorService</code> to send multiple messages in parallel;</li>
	<li>implement repeating of messages in the <code class="language-java">sendMessage</code> method;</li>
	<li>implement the <code class="language-java">stop</code> method to shut down the executor and wait until it stops (it means it blocks a thread that invokes it).</li>
</ul>

<p>Here is an example of a testing code that should successfully work with your implementation.</p>

<pre><code class="language-java">
AsyncMessageSender sender = new AsyncMessageSenderImpl(3);
       
Message[] messages = {

    new Message("John", "Mary", "Hello!"),
    new Message("Clara", "Bruce", "How are you today?")
};

sender.sendMessages(messages);
sender.stop();

notifyAboutEnd(); // it prints something after the sender successfully stop
</code></pre>

<p>Here is the output:</p>

<pre><code class="language-java">(John&gt;Mary): Hello!
(John&gt;Mary): Hello!
(John&gt;Mary): Hello!
(Clara&gt;Bruce): How are you today?
(Clara&gt;Bruce): How are you today?
(Clara&gt;Bruce): How are you today?
Completed.</code></pre>

<p>The order of the sent messages may be different, but the last line must remain the last.</p><br><br><font color="gray">Memory limit: 256 MB</font><br><font color="gray">Time limit: 5 seconds</font><br><br>