nats.docs/_examples/subscribe_w_reply.html

<div class="tab-wrap">
  	
	
	<input type="radio" id="subscribe_w_reply_go" name="subscribe_w_reply" class="tab" checked>
	
	<label for="subscribe_w_reply_go" class="api-lang" data-language="go">Go</label>
	
	
	<input type="radio" id="subscribe_w_reply_java" name="subscribe_w_reply" class="tab">
	
	<label for="subscribe_w_reply_java" class="api-lang" data-language="java">Java</label>
	
	
	<input type="radio" id="subscribe_w_reply_js" name="subscribe_w_reply" class="tab">
	
	<label for="subscribe_w_reply_js" class="api-lang" data-language="js">JavaScript</label>
	
	
	<input type="radio" id="subscribe_w_reply_py" name="subscribe_w_reply" class="tab">
	
	<label for="subscribe_w_reply_py" class="api-lang" data-language="py">Python</label>
	
	
	<input type="radio" id="subscribe_w_reply_ruby" name="subscribe_w_reply" class="tab">
	
	<label for="subscribe_w_reply_ruby" class="api-lang" data-language="ruby">Ruby</label>
	
	
	<input type="radio" id="subscribe_w_reply_ts" name="subscribe_w_reply" class="tab">
	
	<label for="subscribe_w_reply_ts" class="api-lang" data-language="ts">TypeScript</label>
	

  	
	<div class="tab__content">
	<pre id="subscribe_w_reply_go_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/go-nats-examples/blob/master/api-examples/subscribe_w_reply/main.go#L11-36"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-go">nc, err := nats.Connect(&#34;demo.nats.io&#34;)
if err != nil {
	log.Fatal(err)
}
defer nc.Close()

// Subscribe
sub, err := nc.SubscribeSync(&#34;time&#34;)
if err != nil {
	log.Fatal(err)
}

// Read a message
msg, err := sub.NextMsg(10 * time.Second)
if err != nil {
	log.Fatal(err)
}

// Get the time
timeAsBytes := []byte(time.Now().String())

// Send the time as the response.
msg.Respond(timeAsBytes)

</code></pre>
	</div>
	
	<div class="tab__content">
	<pre id="subscribe_w_reply_java_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/java-nats-examples/blob/master/src/main/java/io/nats/examples/SubscribeWithReply.java#L17-37"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-java">Connection nc = Nats.connect(&#34;nats://demo.nats.io:4222&#34;);

// Subscribe
Subscription sub = nc.subscribe(&#34;time&#34;);

// Read a message
Message msg = sub.nextMessage(Duration.ZERO);

// Get the time
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat(&#34;HH:mm:ss&#34;);
byte[] timeAsBytes = sdf.format(cal.getTime()).getBytes(StandardCharsets.UTF_8);

// Send the time
nc.publish(msg.getReplyTo(), timeAsBytes);

// Flush and close the connection
nc.flush(Duration.ZERO);
nc.close();
</code></pre>
	</div>
	
	<div class="tab__content">
	<pre id="subscribe_w_reply_js_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/node-nats-examples/blob/master/src/subscriber_samples.js#L25-36"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-javascript">let nc = NATS.connect({
    url: &#34;nats://demo.nats.io:4222&#34;
});

// set up a subscription to process a request
nc.subscribe(&#39;time&#39;, (msg, reply) =&gt; {
    if (msg.reply) {
        nc.publish(msg.reply, new Date().toLocaleTimeString());
    }
});
</code></pre>
	</div>
	
	<div class="tab__content">
	<pre id="subscribe_w_reply_py_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/asyncio-nats-examples/blob/master/subscribe_w_reply.py#L8-31"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-python">nc = NATS()

await nc.connect(servers=[&#34;nats://demo.nats.io:4222&#34;])

future = asyncio.Future()

async def cb(msg):
  nonlocal future
  future.set_result(msg)

await nc.subscribe(&#34;time&#34;, cb=cb)

await nc.publish_request(&#34;time&#34;, new_inbox(), b&#39;What is the time?&#39;)
await nc.flush()

# Read the message
msg = await asyncio.wait_for(future, 1)

# Send the time
time_as_bytes = &#34;{}&#34;.format(datetime.now()).encode()
await nc.publish(msg.reply, time_as_bytes)

</code></pre>
	</div>
	
	<div class="tab__content">
	<pre id="subscribe_w_reply_ruby_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/ruby-nats-examples/blob/master/subscribe_w_reply.rb#L1-22"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-ruby">require &#39;nats/client&#39;
require &#39;fiber&#39;

NATS.start(servers:[&#34;nats://127.0.0.1:4222&#34;]) do |nc|
  Fiber.new do
    f = Fiber.current

    nc.subscribe(&#34;time&#34;) do |msg, reply|
      f.resume Time.now
    end

    nc.publish(&#34;time&#34;, &#39;What is the time?&#39;, NATS.create_inbox)

    # Use the response
    msg = Fiber.yield
    puts &#34;Reply: #{msg}&#34;

  end.resume
end

</code></pre>
	</div>
	
	<div class="tab__content">
	<pre id="subscribe_w_reply_ts_content"><a class="toolbar-icons pull-right" target="_blank" href="https://github.com/nats-io/ts-nats-examples/blob/master/src/subscriber_samples.ts#L29-38"><i class="mdi mdi-github-circle" title="View on GitHub"></i></a><a class="toolbar-icons pull-right"><i class="mdi mdi-content-copy js-copy" title="Copy to Clipboard"></i></a><span class="copy-msg pull-right"></span><code class="language-javascript">// set up a subscription to process a request
await nc.subscribe(&#39;time&#39;, (err, msg) =&gt; {
    if (msg.reply) {
        nc.publish(msg.reply, new Date().toLocaleTimeString());
    } else {
        t.log(&#39;got a request for the time, but no reply subject was set.&#39;);
    }
});
</code></pre>
	</div>
	
</div>