blob: 5f30ea30a360463f12866a3a183902e3100097f0 [file] [log] [blame]
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="">
<meta name="keywords" content="protocol, protocol, examples">
<title> Protocol examples • Eclipse Ditto • a digital twin framework</title>
<link rel="stylesheet" href="css/syntax.css">
<link rel="stylesheet" type="text/css" href="//cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" crossorigin="anonymous">
<link rel="stylesheet" href="css/modern-business.css">
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" crossorigin="anonymous">
<link rel="stylesheet" href="css/customstyles.css">
<link rel="stylesheet" href="css/boxshadowproperties.css">
<link rel="stylesheet" href="css/theme-ditto.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:400,700|Source+Code+Pro:300,600|Titillium+Web:400,600,700">
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.min.js" crossorigin="anonymous"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js" crossorigin="anonymous"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/anchor-js/2.0.0/anchor.min.js" crossorigin="anonymous"></script>
<script src="js/toc.js"></script>
<script src="js/customscripts.js"></script>
<script type="application/ld+json">
{
"@context": "http://schema.org",
"@type": "Organization",
"url": "https://eclipse.org/ditto/",
"logo": "https://eclipse.org/ditto/images/ditto.svg"
}
</script>
<link rel="icon" type="image/png" href="images/favicon-16x16.png" sizes="16x16">
<link rel="icon" type="image/png" href="images/favicon-32x32.png" sizes="32x32">
<link rel="icon" type="image/png" href="images/favicon-96x96.png" sizes="96x96">
<link rel="alternate" type="application/rss+xml" title="Eclipse Ditto Blog" href="https://www.eclipse.org/ditto/feed.xml">
<!-- Eclipse Foundation cookie consent: -->
<link rel="stylesheet" type="text/css" href="//www.eclipse.org/eclipse.org-common/themes/solstice/public/stylesheets/vendor/cookieconsent/cookieconsent.min.css" />
<script src="//www.eclipse.org/eclipse.org-common/themes/solstice/public/javascript/vendor/cookieconsent/default.min.js"></script>
<script>
$(document).ready(function() {
$("#tg-sb-link").click(function() {
$("#tg-sb-sidebar").toggle();
$("#tg-sb-content").toggleClass('col-md-9');
$("#tg-sb-content").toggleClass('col-md-12');
$("#tg-sb-icon").toggleClass('fa-toggle-on');
$("#tg-sb-icon").toggleClass('fa-toggle-off');
});
});
</script>
</head>
<script>
(function(w,d,s,l,i){
w[l]=w[l]||[];
w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});
var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),
dl=l!='dataLayer'?'&l='+l:'';
j.async=true;
j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;
f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-5WLCZXC');
</script>
<body>
<!-- Navigation -->
<nav class="navbar navbar-inverse navbar-fixed-top">
<div class="container topnavlinks">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-ditto-home" href="index.html">&nbsp;<img src="images/ditto_allwhite_symbolonly.svg" class="ditto-navbar-symbol" alt="Home"> <img src="images/ditto_allwhite_textonly.svg" class="ditto-navbar-symbol-text" alt="Ditto"></a>
</div>
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav navbar-right">
<!-- toggle sidebar button -->
<!--<li><a id="tg-sb-link" href="#"><i id="tg-sb-icon" class="fa fa-toggle-on"></i> Nav</a></li>-->
<!-- entries without drop-downs appear here -->
<li><a href="blog.html">Blog</a></li>
<li><a href="intro-overview.html">Documentation</a></li>
<li><a href="http-api-doc.html">HTTP API</a></li>
<li><a href="sandbox.html">Sandbox</a></li>
<li><a href="https://github.com/eclipse/ditto" target="_blank">GitHub</a></li>
<li><a href="https://github.com/eclipse/ditto-examples" target="_blank">GitHub examples</a></li>
<!-- entries with drop-downs appear here -->
<!-- conditional logic to control which topnav appears for the audience defined in the configuration file.-->
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Links<b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="https://projects.eclipse.org/projects/iot.ditto" target="_blank">Eclipse Ditto Project</a></li>
<li><a href="https://www.eclipse.org/forums/index.php/f/364/" target="_blank">Forum</a></li>
<li><a href="https://ci.eclipse.org/ditto/" target="_blank">Jenkins</a></li>
<li><a href="https://dev.eclipse.org/mhonarc/lists/ditto-dev/" target="_blank">Mailing list archives</a></li>
<li><a href="https://gitter.im/eclipse/ditto" target="_blank">Gitter.im chat</a></li>
</ul>
</li>
<!--comment out this block if you want to hide search-->
<li>
<!--start search-->
<div id="search-demo-container">
<input type="text" id="search-input" placeholder="search...">
<ul id="results-container"></ul>
</div>
<script src="//cdnjs.cloudflare.com/ajax/libs/simple-jekyll-search/0.0.9/jekyll-search.js" type="text/javascript"></script>
<script type="text/javascript">
SimpleJekyllSearch.init({
searchInput: document.getElementById('search-input'),
resultsContainer: document.getElementById('results-container'),
dataSource: 'search.json',
searchResultTemplate: '<li><a href="{url}" title="Protocol examples">{title}</a></li>',
noResultsText: 'No results found.',
limit: 10,
fuzzy: true,
})
</script>
<!--end search-->
</li>
</ul>
</div>
</div>
<!-- /.container -->
</nav>
<!-- Page Content -->
<div class="container">
<div id="main">
<!-- Content Row -->
<div class="row">
<!-- Sidebar Column -->
<div class="col-md-3" id="tg-sb-sidebar">
<ul id="mysidebar" class="nav">
<li class="sidebarTitle">
<label for="docVersion">Eclipse Ditto version:</label>
<div class="select-wrapper">
<select id="docVersion" name="docVersion">
<option value="">development</option>
<option value="1.0">1.0</option>
<option value="1.1">1.1</option>
<option value="1.2">1.2</option>
<option value="1.3">1.3</option>
<option value="1.4">1.4</option>
<option value="1.5">1.5</option>
</select>
</div>
<div id="dev-warning">
<div markdown="span" class="alert alert-warning" role="alert" style="font-size:0.6em"><i class="fa fa-warning"></i> <b>Important:</b> This documentation reflects the latest 'development'. You might want to choose a released version.</div>
</div>
</li>
<li class="subfolders">
<a href="#"><span></span>Introduction</a>
<ul>
<li><a href="intro-overview.html">Overview</a></li>
<li><a href="intro-digitaltwins.html">Digital twins</a></li>
<li><a href="intro-hello-world.html">Hello world</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Release Notes</a>
<ul>
<li><a href="release_notes_151.html">1.5.1</a></li>
<li><a href="release_notes_150.html">1.5.0</a></li>
<li><a href="release_notes_140.html">1.4.0</a></li>
<li><a href="release_notes_130.html">1.3.0</a></li>
<li><a href="release_notes_121.html">1.2.1</a></li>
<li><a href="release_notes_120.html">1.2.0</a></li>
<li><a href="release_notes_115.html">1.1.5</a></li>
<li><a href="release_notes_113.html">1.1.3</a></li>
<li><a href="release_notes_112.html">1.1.2</a></li>
<li><a href="release_notes_111.html">1.1.1</a></li>
<li><a href="release_notes_110.html">1.1.0</a></li>
<li><a href="release_notes_100.html">1.0.0</a></li>
<li><a href="release_notes_090.html">0.9.0</a></li>
<li><a href="release_notes_080.html">0.8.0</a></li>
<li class="subfolders">
<a href="#"><span></span>Milestone releases</a>
<ul>
<li><a href="release_notes_100-M2.html">1.0.0-M2</a></li>
<li><a href="release_notes_100-M1a.html">1.0.0-M1a</a></li>
<li><a href="release_notes_090-M2.html">0.9.0-M2</a></li>
<li><a href="release_notes_090-M1.html">0.9.0-M1</a></li>
<li><a href="release_notes_080-M3.html">0.8.0-M3</a></li>
<li><a href="release_notes_080-M2.html">0.8.0-M2</a></li>
<li><a href="release_notes_080-M1.html">0.8.0-M1</a></li>
<li><a href="release_notes_030-M2.html">0.3.0-M2</a></li>
<li><a href="release_notes_030-M1.html">0.3.0-M1</a></li>
<li><a href="release_notes_020-M1.html">0.2.0-M1</a></li>
<li><a href="release_notes_010-M3.html">0.1.0-M3</a></li>
<li><a href="release_notes_010-M1.html">0.1.0-M1</a></li>
</ul>
</li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Installation</a>
<ul>
<li><a href="installation-building.html">Building Ditto</a></li>
<li><a href="installation-running.html">Running Ditto</a></li>
<li><a href="installation-operating.html">Operating Ditto</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Basic concepts</a>
<ul>
<li><a href="basic-overview.html">Overview</a></li>
<li class="subfolders">
<a href="#"><span></span>Model entities</a>
<ul>
<li><a href="basic-thing.html">Thing</a></li>
<li><a href="basic-acl.html">Access Control List (ACL)</a></li>
<li><a href="basic-feature.html">Feature</a></li>
<li><a href="basic-policy.html">Policy</a></li>
<li><a href="basic-namespaces-and-names.html">Namespaces and Names</a></li>
<li><a href="basic-metadata.html">Thing Metadata</a></li>
<li><a href="basic-errors.html">Errors</a></li>
</ul>
</li>
<li><a href="basic-auth.html">Authentication and Authorization</a></li>
<li><a href="basic-messages.html">Messages</a></li>
<li><a href="basic-signals.html">Signals</a></li>
<li class="subfolders">
<a href="#"><span></span>Signal types</a>
<ul>
<li><a href="basic-signals-command.html">Command</a></li>
<li><a href="basic-signals-commandresponse.html">Command response</a></li>
<li><a href="basic-signals-errorresponse.html">Error response</a></li>
<li><a href="basic-signals-event.html">Event</a></li>
</ul>
</li>
<li><a href="basic-apis.html">APIs</a></li>
<li><a href="basic-connections.html">Connections</a></li>
<li><a href="basic-placeholders.html">Placeholders</a></li>
<li><a href="basic-changenotifications.html">Change notifications</a></li>
<li><a href="basic-rql.html">RQL expressions</a></li>
<li><a href="basic-enrichment.html">Signal enrichment</a></li>
<li><a href="basic-search.html">Search</a></li>
<li><a href="basic-acknowledgements.html">Acknowledgements / QoS</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Architecture</a>
<ul>
<li><a href="architecture-overview.html">Overview</a></li>
<li class="subfolders">
<a href="#"><span></span>Services</a>
<ul>
<li><a href="architecture-services-policies.html">Policies</a></li>
<li><a href="architecture-services-things.html">Things</a></li>
<li><a href="architecture-services-things-search.html">Things-Search</a></li>
<li><a href="architecture-services-connectivity.html">Connectivity</a></li>
<li><a href="architecture-services-concierge.html">Concierge</a></li>
<li><a href="architecture-services-gateway.html">Gateway</a></li>
</ul>
</li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>HTTP API</a>
<ul>
<li><a href="httpapi-overview.html">Overview</a></li>
<li><a href="httpapi-concepts.html">Concepts</a></li>
<li><a href="httpapi-search.html">Search</a></li>
<li><a href="httpapi-messages.html">Messages</a></li>
<li><a href="httpapi-protocol-bindings-websocket.html">WebSocket protocol binding</a></li>
<li><a href="httpapi-protocol-bindings-cloudevents.html">Cloud Events HTTP protocol binding</a></li>
<li><a href="httpapi-sse.html">Server sent events</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Connectivity API</a>
<ul>
<li><a href="connectivity-overview.html">Overview</a></li>
<li><a href="connectivity-manage-connections.html">Manage connections</a></li>
<li><a href="connectivity-protocol-bindings-amqp091.html">AMQP 0.9.1 protocol binding</a></li>
<li><a href="connectivity-protocol-bindings-amqp10.html">AMQP 1.0 protocol binding</a></li>
<li><a href="connectivity-protocol-bindings-mqtt.html">MQTT 3.1.1 protocol binding</a></li>
<li><a href="connectivity-protocol-bindings-mqtt5.html">MQTT 5 protocol binding</a></li>
<li><a href="connectivity-protocol-bindings-http.html">HTTP 1.1 protocol binding</a></li>
<li><a href="connectivity-protocol-bindings-kafka2.html">Kafka 2.x protocol binding</a></li>
<li><a href="connectivity-mapping.html">Payload mapping</a></li>
<li><a href="connectivity-header-mapping.html">Header mapping</a></li>
<li><a href="connectivity-tls-certificates.html">TLS certificates</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Client SDK</a>
<ul>
<li><a href="client-sdk-overview.html">Overview</a></li>
<li><a href="client-sdk-java.html">Java</a></li>
<li><a href="client-sdk-javascript.html">JavaScript</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>Ditto Protocol</a>
<ul>
<li><a href="protocol-overview.html">Overview</a></li>
<li><a href="protocol-twinlive.html">Twin/live channel</a></li>
<li><a href="protocol-specification.html">Specification</a></li>
<li><a href="protocol-specification-topic.html">Protocol topic</a></li>
<li><a href="protocol-specification-things.html">Things group</a></li>
<li class="subfolders">
<a href="#"><span></span>→ commands/events</a>
<ul>
<li><a href="protocol-specification-things-create-or-modify.html">Create/Modify</a></li>
<li><a href="protocol-specification-things-retrieve.html">Retrieve</a></li>
<li><a href="protocol-specification-things-delete.html">Delete</a></li>
<li><a href="protocol-specification-acks.html">Acknowledgements</a></li>
<li><a href="protocol-specification-errors.html">Errors</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>→ search/messages</a>
<ul>
<li><a href="protocol-specification-things-search.html">Search</a></li>
<li><a href="protocol-specification-things-messages.html">Messages</a></li>
</ul>
</li>
<li><a href="protocol-specification-policies.html">Policies group</a></li>
<li class="subfolders">
<a href="#"><span></span>→ commands/events</a>
<ul>
<li><a href="protocol-specification-policies-create-or-modify.html">Create/Modify</a></li>
<li><a href="protocol-specification-policies-retrieve.html">Retrieve</a></li>
<li><a href="protocol-specification-policies-delete.html">Delete</a></li>
</ul>
</li>
<li><a href="protocol-bindings.html">Bindings</a></li>
<li class="active"><a href="protocol-examples.html">Examples</a></li>
<li class="subfolders">
<a href="#"><span></span>→ Things examples</a>
<ul>
<li><a href="protocol-examples-creatething.html">Create a Thing</a></li>
<li><a href="protocol-examples-deletething.html">Delete a Thing</a></li>
<li><a href="protocol-examples-modifything.html">Modify a Thing</a></li>
<li><a href="protocol-examples-retrievething.html">Retrieve a Thing</a></li>
<li><a href="protocol-examples-retrievethings.html">Retrieve multiple Things</a></li>
<li><a href="protocol-examples-modifypolicyid.html">Modify the Policy ID of a Thing</a></li>
<li><a href="protocol-examples-createattributes.html">Create Attributes</a></li>
<li><a href="protocol-examples-deleteattributes.html">Delete Attributes</a></li>
<li><a href="protocol-examples-modifyattributes.html">Modify Attributes</a></li>
<li><a href="protocol-examples-retrieveattributes.html">Retrieve Attributes</a></li>
<li><a href="protocol-examples-createattribute.html">Create a single Attribute</a></li>
<li><a href="protocol-examples-deleteattribute.html">Delete a single Attribute</a></li>
<li><a href="protocol-examples-modifyattribute.html">Modify a single Attribute</a></li>
<li><a href="protocol-examples-retrieveattribute.html">Retrieve a single Attribute</a></li>
<li><a href="protocol-examples-createthingdefinition.html">Create a Definition</a></li>
<li><a href="protocol-examples-deletethingdefinition.html">Delete a Definition</a></li>
<li><a href="protocol-examples-modifythingdefinition.html">Modify a Definition</a></li>
<li><a href="protocol-examples-retrievethingdefinition.html">Retrieve a Definition</a></li>
<li><a href="protocol-examples-createfeatures.html">Create Features</a></li>
<li><a href="protocol-examples-deletefeatures.html">Delete Features</a></li>
<li><a href="protocol-examples-modifyfeatures.html">Modify Features</a></li>
<li><a href="protocol-examples-retrievefeatures.html">Retrieve Features</a></li>
<li><a href="protocol-examples-createfeature.html">Create a single Feature</a></li>
<li><a href="protocol-examples-deletefeature.html">Delete a single Feature</a></li>
<li><a href="protocol-examples-modifyfeature.html">Modify a single Feature</a></li>
<li><a href="protocol-examples-retrievefeature.html">Retrieve a single Feature</a></li>
<li><a href="protocol-examples-createdefinition.html">Create Feature Definition</a></li>
<li><a href="protocol-examples-deletedefinition.html">Delete Feature Definition</a></li>
<li><a href="protocol-examples-modifydefinition.html">Modify Feature Definition</a></li>
<li><a href="protocol-examples-retrievedefinition.html">Retrieve Feature Definition</a></li>
<li><a href="protocol-examples-createproperties.html">Create Feature Properties</a></li>
<li><a href="protocol-examples-deleteproperties.html">Delete Feature Properties</a></li>
<li><a href="protocol-examples-modifyproperties.html">Modify Feature Properties</a></li>
<li><a href="protocol-examples-retrieveproperties.html">Retrieve Feature Properties</a></li>
<li><a href="protocol-examples-createproperty.html">Create a single Property</a></li>
<li><a href="protocol-examples-deleteproperty.html">Delete a single Property</a></li>
<li><a href="protocol-examples-modifyproperty.html">Modify a single Property</a></li>
<li><a href="protocol-examples-retrieveproperty.html">Retrieve a single Property</a></li>
<li><a href="protocol-examples-createdesiredproperties.html">Create desired Feature Properties</a></li>
<li><a href="protocol-examples-deletedesiredproperties.html">Delete desired Feature Properties</a></li>
<li><a href="protocol-examples-modifydesiredproperties.html">Modify desired Feature Properties</a></li>
<li><a href="protocol-examples-retrievedesiredproperties.html">Retrieve desired Feature Properties</a></li>
<li><a href="protocol-examples-createdesiredproperty.html">Create a single desired Property</a></li>
<li><a href="protocol-examples-deletedesiredproperty.html">Delete a single desired Property</a></li>
<li><a href="protocol-examples-modifydesiredproperty.html">Modify a single desired Property</a></li>
<li><a href="protocol-examples-retrievedesiredproperty.html">Retrieve a single desired Property</a></li>
<li><a href="protocol-examples-errorresponses.html">Error responses</a></li>
</ul>
</li>
<li class="subfolders">
<a href="#"><span></span>→ Policies examples</a>
<ul>
<li><a href="protocol-examples-policies-createpolicy.html">Create a Policy</a></li>
<li><a href="protocol-examples-policies-deletepolicy.html">Delete a Policy</a></li>
<li><a href="protocol-examples-policies-modifypolicy.html">Modify a Policy</a></li>
<li><a href="protocol-examples-policies-retrievepolicy.html">Retrieve a Policy</a></li>
<li><a href="protocol-examples-policies-modifypolicyentries.html">Modify entries</a></li>
<li><a href="protocol-examples-policies-retrievepolicyentries.html">Retrieve entries</a></li>
<li><a href="protocol-examples-policies-createpolicyentry.html">Create a single entry</a></li>
<li><a href="protocol-examples-policies-deletepolicyentry.html">Delete a single entry</a></li>
<li><a href="protocol-examples-policies-modifypolicyentry.html">Modify a single entry</a></li>
<li><a href="protocol-examples-policies-retrievepolicyentry.html">Retrieve a single entry</a></li>
<li><a href="protocol-examples-policies-modifysubjects.html">Modify subjects</a></li>
<li><a href="protocol-examples-policies-retrievesubjects.html">Retrieve subjects</a></li>
<li><a href="protocol-examples-policies-createsubject.html">Create a single subject</a></li>
<li><a href="protocol-examples-policies-deletesubject.html">Delete a single subject</a></li>
<li><a href="protocol-examples-policies-modifysubject.html">Modify a single subject</a></li>
<li><a href="protocol-examples-policies-retrievesubject.html">Retrieve a single subject</a></li>
<li><a href="protocol-examples-policies-modifyresources.html">Modify resources</a></li>
<li><a href="protocol-examples-policies-retrieveresources.html">Retrieve resources</a></li>
<li><a href="protocol-examples-policies-createresource.html">Create a single resource</a></li>
<li><a href="protocol-examples-policies-deleteresource.html">Delete a single resource</a></li>
<li><a href="protocol-examples-policies-modifyresource.html">Modify a single resource</a></li>
<li><a href="protocol-examples-policies-retrieveresource.html">Retrieve a single resource</a></li>
<li><a href="protocol-examples-policies-errorresponses.html">Error responses</a></li>
</ul>
</li>
<li><a href="protocol-examples-search.html">→ Search examples</a></li>
</ul>
</li>
<li><a href="sandbox.html">Sandbox</a></li>
<li><a href="presentations.html">Presentations</a></li>
<li><a href="glossary.html">Glossary</a></li>
<li><a href="feedback.html">Feedback</a></li>
<p class="external">
<a href="#" id="collapseAll">Collapse All</a> | <a href="#" id="expandAll">Expand All</a>
</p>
</ul>
<!-- this highlights the active parent class in the sidebar. this is critical so that the parent expands when you're viewing a page. This must appear below the sidebar code above. Otherwise, if placed inside customscripts.js, the script runs before the sidebar code runs and the class never gets inserted.-->
<script>$("li.active").parents('li').toggleClass("active");
</script>
</div>
<!-- Content Column -->
<div class="col-md-9" id="tg-sb-content">
<div class="post-header">
<h1 class="post-title-main">Protocol examples</h1>
</div>
<div class="post-content">
<!-- this handles the automatic toc. use ## for subheads to auto-generate the on-page minitoc. if you use html tags, you must supply an ID for the heading element in order for it to appear in the minitoc. -->
<script>
$( document ).ready(function() {
// Handler for .ready() called.
$('#toc').toc({ minimumHeaders: 0, listType: 'ul', showSpeed: 0, headers: 'h2,h3,h4' });
/* this offset helps account for the space taken up by the floating toolbar. */
$('#toc').on('click', 'a', function() {
var target = $(this.getAttribute('href'))
, scroll_target = target.offset().top
$(window).scrollTop(scroll_target - 10);
return false
})
});
</script>
<div id="toc"></div>
<p>The structure of the examples in this section is as follows:</p>
<h2 id="command">Command</h2>
<p>Each example always starts with a command message that initiates an operation at Ditto (e.g. create a thing, retrieve a thing).</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"topic"</span><span class="p">:</span><span class="w"> </span><span class="s2">"com.acme/xdk_58/things/twin/commands/modify"</span><span class="p">,</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="p">,</span><span class="w">
</span><span class="s2">"requested-acks"</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="s2">"twin-persisted"</span><span class="p">,</span><span class="s2">"custom-ack"</span><span class="w"> </span><span class="p">]</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="w">
</span><span class="err">...</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<h2 id="response">Response</h2>
<p>A command always has a response which either reports the success or the failure. The example contains the success response.
See Thing Error responses for examples of messages that will be returned in case of an error.</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="p">,</span><span class="w">
</span><span class="s2">"value"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="err">...</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"status"</span><span class="p">:</span><span class="w"> </span><span class="mi">204</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<h2 id="event">Event</h2>
<p>If Ditto triggers an event (e.g. Thing created, Attribute modified) as a result of the executed command, an example of such an event is also demonstrated.</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"topic"</span><span class="p">:</span><span class="w"> </span><span class="s2">"com.acme/thing_id_3141/things/twin/events/modified"</span><span class="p">,</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="p">,</span><span class="w">
</span><span class="s2">"requested-acks"</span><span class="p">:</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="s2">"custom-ack"</span><span class="w"> </span><span class="p">]</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="p">,</span><span class="w">
</span><span class="s2">"value"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="err">...</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"revision"</span><span class="p">:</span><span class="w"> </span><span class="mi">1</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<h2 id="acknowledgements-acks">Acknowledgements (ACKs)</h2>
<p>A command issuer can require a response and specify the acknowledgements (ACKs) which have to be successfully fulfilled
to regard the command as successfully executed.</p>
<p>Below an example is given for a successfully fulfilled ACK (status 202):</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"topic"</span><span class="p">:</span><span class="w"> </span><span class="s2">"com.acme/thing_name_3141/things/twin/acks/custom-ack"</span><span class="p">,</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="p">,</span><span class="w">
</span><span class="s2">"status"</span><span class="p">:</span><span class="w"> </span><span class="mi">202</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<p>And here is an example for a failed ACK (aka NACK, status 400):</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"topic"</span><span class="p">:</span><span class="w"> </span><span class="s2">"com.acme/thing_name_3141/things/twin/acks/custom-ack"</span><span class="p">,</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="p">,</span><span class="w">
</span><span class="s2">"value"</span><span class="p">:</span><span class="w"> </span><span class="s2">"You better try harder"</span><span class="p">,</span><span class="w">
</span><span class="s2">"status"</span><span class="p">:</span><span class="w"> </span><span class="mi">400</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<p>An ACK representing a timeout would look like this:</p>
<div class="language-json highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="p">{</span><span class="w">
</span><span class="s2">"topic"</span><span class="p">:</span><span class="w"> </span><span class="s2">"com.acme/thing_name_3141/things/twin/acks/custom-ack"</span><span class="p">,</span><span class="w">
</span><span class="s2">"headers"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"correlation-id"</span><span class="p">:</span><span class="w"> </span><span class="s2">"a780b7b5-fdd2-4864-91fc-80df6bb0a636"</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"path"</span><span class="p">:</span><span class="w"> </span><span class="s2">"/"</span><span class="p">,</span><span class="w">
</span><span class="s2">"value"</span><span class="p">:</span><span class="w"> </span><span class="p">{</span><span class="w">
</span><span class="s2">"status"</span><span class="p">:</span><span class="w"> </span><span class="mi">408</span><span class="p">,</span><span class="w">
</span><span class="s2">"error"</span><span class="p">:</span><span class="w"> </span><span class="s2">"acknowledgement:request.timeout"</span><span class="p">,</span><span class="w">
</span><span class="s2">"message"</span><span class="p">:</span><span class="w"> </span><span class="s2">"The acknowledgement request reached the specified timeout of 1,337ms."</span><span class="p">,</span><span class="w">
</span><span class="s2">"description"</span><span class="p">:</span><span class="w"> </span><span class="s2">"Try increasing the timeout and make sure that the requested acknowledgement is sent back in time."</span><span class="w">
</span><span class="p">},</span><span class="w">
</span><span class="s2">"status"</span><span class="p">:</span><span class="w"> </span><span class="mi">408</span><span class="w">
</span><span class="p">}</span><span class="w">
</span></code></pre></div></div>
<div class="tags">
<b>Tags: </b>
<a href="tag_protocol.html" class="btn btn-default navbar-btn cursorNorm" role="button">protocol</a>
</div>
</div>
<hr class="shaded"/>
<footer>
<div class="row">
<div class="col-lg-12 footer">
<div class="logo">
<a href="https://eclipse.org"><img src="images/eclipse_foundation_logo.svg" alt="Eclipse logo"/></a>
</div>
<p class="notice">
&copy;2021 Eclipse Ditto.
Site last generated: Apr 6, 2021 <br />
</p>
<div class="quickLinks">
<a href="https://www.eclipse.org/legal/privacy.php" target="_blank">
&gt; Privacy Policy
</a>
<a href="https://www.eclipse.org/legal/termsofuse.php" target="_blank">
&gt; Terms of Use
</a>
<a href="https://www.eclipse.org/legal/copyright.php" target="_blank">
&gt; Copyright Agent
</a>
<a href="https://www.eclipse.org/legal" target="_blank">
&gt; Legal
</a>
<a href="https://www.eclipse.org/legal/epl-2.0/" target="_blank">
&gt; License
</a>
<a href="https://eclipse.org/security" target="_blank">
&gt; Report a Vulnerability
</a>
</div>
</div>
</div>
</footer>
</div>
<!-- /.row -->
</div>
<!-- /.container -->
</div>
<!-- /#main -->
</div>
</body>
</html>