| <!DOCTYPE html> |
| <html lang="en"> |
| <head> |
| |
| |
| <title>Apache Jena - ARQ - Querying Remote SPARQL Services</title> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"> |
| |
| <link href="/css/bootstrap.min.css" rel="stylesheet" media="screen"> |
| <link href="/css/bootstrap-icons.css" rel="stylesheet" media="screen"><link rel="stylesheet" type="text/css" href="https://jena.apache.org/sass/jena.1b17c39a117e22b46db4c66f6395dc27c134a60377d87d2d5745b8600eb69722.css" integrity="sha256-GxfDmhF+IrRttMZvY5XcJ8E0pgN32H0tV0W4YA62lyI="> |
| <link rel="shortcut icon" href="/images/favicon.ico" /> |
| |
| </head> |
| |
| <body> |
| |
| <nav class="navbar navbar-expand-lg bg-body-tertiary" role="navigation"> |
| <div class="container"> |
| <div class="navbar-header"> |
| <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation"> |
| <span class="navbar-toggler-icon"></span> |
| </button> |
| <a class="navbar-brand" href="/index.html"> |
| <img class="logo-menu" src="/images/jena-logo/jena-logo-notext-small.png" alt="jena logo">Apache Jena</a> |
| </div> |
| |
| <div class="collapse navbar-collapse" id="navbarNav"> |
| <ul class="navbar-nav me-auto mb-2 mb-lg-0"> |
| <li id="homepage" class="nav-item"><a class="nav-link" href="/index.html"><span class="bi-house"></span> Home</a></li> |
| <li id="download" class="nav-item"><a class="nav-link" href="/download/index.cgi"><span class="bi-download"></span> Download</a></li> |
| <li class="nav-item dropdown"> |
| <a href="#" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-journal"></span> Learn <b class="caret"></b></a> |
| <ul class="dropdown-menu"> |
| <li class="dropdown-header">Tutorials</li> |
| <li><a class="dropdown-item" href="/tutorials/index.html">Overview</a></li> |
| <li><a class="dropdown-item" href="/documentation/fuseki2/index.html">Fuseki Triplestore</a></li> |
| <li><a class="dropdown-item" href="/documentation/notes/index.html">How-To's</a></li> |
| <li><a class="dropdown-item" href="/documentation/query/manipulating_sparql_using_arq.html">Manipulating SPARQL using ARQ</a></li> |
| <li><a class="dropdown-item" href="/tutorials/rdf_api.html">RDF core API tutorial</a></li> |
| <li><a class="dropdown-item" href="/tutorials/sparql.html">SPARQL tutorial</a></li> |
| <li><a class="dropdown-item" href="/tutorials/using_jena_with_eclipse.html">Using Jena with Eclipse</a></li> |
| <li class="dropdown-divider"></li> |
| <li class="dropdown-header">References</li> |
| <li><a class="dropdown-item" href="/documentation/index.html">Overview</a></li> |
| <li><a class="dropdown-item" href="/documentation/query/index.html">ARQ (SPARQL)</a></li> |
| <li><a class="dropdown-item" href="/documentation/io/">RDF I/O</a></li> |
| <li><a class="dropdown-item" href="/documentation/assembler/index.html">Assembler</a></li> |
| <li><a class="dropdown-item" href="/documentation/tools/index.html">Command-line tools</a></li> |
| <li><a class="dropdown-item" href="/documentation/rdfs/">Data with RDFS Inferencing</a></li> |
| <li><a class="dropdown-item" href="/documentation/geosparql/index.html">GeoSPARQL</a></li> |
| <li><a class="dropdown-item" href="/documentation/inference/index.html">Inference API</a></li> |
| <li><a class="dropdown-item" href="/documentation/ontology/">Ontology API</a></li> |
| <li><a class="dropdown-item" href="/documentation/permissions/index.html">Permissions</a></li> |
| <li><a class="dropdown-item" href="/documentation/extras/querybuilder/index.html">Query Builder</a></li> |
| <li><a class="dropdown-item" href="/documentation/rdf/index.html">RDF API</a></li> |
| <li><a class="dropdown-item" href="/documentation/rdfconnection/">RDF Connection - SPARQL API</a></li> |
| <li><a class="dropdown-item" href="/documentation/rdfstar/index.html">RDF-star</a></li> |
| <li><a class="dropdown-item" href="/documentation/shacl/index.html">SHACL</a></li> |
| <li><a class="dropdown-item" href="/documentation/shex/index.html">ShEx</a></li> |
| <li><a class="dropdown-item" href="/documentation/tdb/index.html">TDB</a></li> |
| <li><a class="dropdown-item" href="/documentation/tdb2/index.html">TDB2</a></li> |
| <li><a class="dropdown-item" href="/documentation/query/text-query.html">Text Search</a></li> |
| </ul> |
| </li> |
| |
| <li class="nav-item dropdown"> |
| <a href="#" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-journal-code"></span> Javadoc <b class="caret"></b></a> |
| <ul class="dropdown-menu"> |
| <li><a class="dropdown-item" href="/documentation/javadoc.html">All Javadoc</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/arq/">ARQ</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/fuseki2/">Fuseki</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/geosparql/">GeoSPARQL</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/jena/">Jena Core</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/permissions/">Permissions</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/extras/querybuilder/">Query Builder</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/shacl/">SHACL</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/tdb/">TDB</a></li> |
| <li><a class="dropdown-item" href="/documentation/javadoc/text/">Text Search</a></li> |
| </ul> |
| </li> |
| </ul> |
| <form class="d-flex" role="search" action="/search" method="GET"> |
| <div class="input-group"> |
| <input class="form-control border-end-0 border m-0" type="search" name="q" id="search-query" placeholder="Search...." aria-label="Search" style="width: 10rem;"> |
| <button class="btn btn-outline-secondary border-start-0 border" type="submit"> |
| <i class="bi-search"></i> |
| </button> |
| </div> |
| </form> |
| <ul class="navbar-nav"> |
| <li id="ask" class="nav-item"><a class="nav-link" href="/help_and_support/index.html" title="Ask"><span class="bi-patch-question"></span><span class="text-body d-none d-xxl-inline"> Ask</span></a></li> |
| |
| <li class="nav-item dropdown"> |
| <a href="#" title="Get involved" class="nav-link dropdown-toggle" role="button" data-bs-toggle="dropdown" aria-expanded="false"><span class="bi-megaphone"></span><span class="text-body d-none d-xxl-inline"> Get involved </span><b class="caret"></b></a> |
| <ul class="dropdown-menu"> |
| <li><a class="dropdown-item" href="/getting_involved/index.html">Contribute</a></li> |
| <li><a class="dropdown-item" href="/help_and_support/bugs_and_suggestions.html">Report a bug</a></li> |
| <li class="dropdown-divider"></li> |
| <li class="dropdown-header">Project</li> |
| <li><a class="dropdown-item" href="/about_jena/about.html">About Jena</a></li> |
| <li><a class="dropdown-item" href="/about_jena/architecture.html">Architecture</a></li> |
| <li><a class="dropdown-item" href="/about_jena/citing.html">Citing</a></li> |
| <li><a class="dropdown-item" href="/about_jena/team.html">Project team</a></li> |
| <li><a class="dropdown-item" href="/about_jena/contributions.html">Related projects</a></li> |
| <li><a class="dropdown-item" href="/about_jena/roadmap.html">Roadmap</a></li> |
| <li><a class="dropdown-item" href="/about_jena/security-advisories.html">Security Advisories</a></li> |
| <li class="dropdown-divider"></li> |
| <li class="dropdown-header">ASF</li> |
| <li><a class="dropdown-item" href="https://www.apache.org/">Apache Software Foundation</a></li> |
| <li><a class="dropdown-item" href="https://www.apache.org/foundation/sponsorship.html">Become a Sponsor</a></li> |
| <li><a class="dropdown-item" href="https://www.apache.org/licenses/LICENSE-2.0">License</a></li> |
| <li><a class="dropdown-item" href="https://www.apache.org/security/">Security</a></li> |
| <li><a class="dropdown-item" href="https://www.apache.org/foundation/thanks.html">Thanks</a></li> |
| </ul> |
| </li> |
| |
| |
| |
| |
| <li class="nav-item" id="edit"><a class="nav-link" href="https://github.com/apache/jena-site/edit/main/source/documentation/query/sparql-remote.md" title="Edit this page on GitHub"><span class="bi-pencil-square"></span><span class="text-body d-none d-xxl-inline"> Edit this page</span></a></li> |
| </ul> |
| </div> |
| </div> |
| </nav> |
| |
| <div class="container"> |
| <div class="row"> |
| <div class="col-md-12"> |
| |
| <div id="breadcrumbs"> |
|
|
|
|
|
|
|
|
|
|
|
|
| <ol class="breadcrumb mt-4 p-2 bg-body-tertiary">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| <li class="breadcrumb-item"><a href='/documentation'>DOCUMENTATION</a></li>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| <li class="breadcrumb-item"><a href='/documentation/query'>QUERY</a></li>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| <li class="breadcrumb-item active">SPARQL REMOTE</li>
|
|
|
|
|
|
|
|
|
| </ol>
|
|
|
|
|
|
|
| |
| </div> |
| <h1 class="title">ARQ - Querying Remote SPARQL Services</h1> |
| |
| |
| <main class="d-flex flex-xl-row flex-column"> |
| |
| <aside class="text-muted align-self-start mb-3 p-0 d-xl-none d-block"> |
| <h2 class="h6 sticky-top m-0 p-2 bg-body-tertiary">On this page</h2> |
| <nav id="TableOfContents"> |
| <ul> |
| <li><a href="#from-your-application">From your application</a></li> |
| <li><a href="#from-the-command-line">From the command line</a></li> |
| <li><a href="#authentication">Authentication</a></li> |
| <li><a href="#firewalls-and-proxies">Firewalls and Proxies</a></li> |
| </ul> |
| </nav> |
| </aside> |
| <article class="flex-column me-lg-4"> |
| <p>SPARQL is a |
| <a href="http://www.w3.org/TR/sparql11-query/">query language</a> and a |
| <a href="http://www.w3.org/2001/sw/DataAccess/proto-wd/">remote access protocol</a>. |
| The remote access protocol runs over HTTP.</p> |
| <p>See <a href="../fuseki2/index.html">Fuseki</a> for an implementation of the |
| SPARQL protocol over HTTP. Fuseki uses ARQ to provide SPARQL |
| query access to Jena models, including Jena persistent models.</p> |
| <p>ARQ includes a query engine capable of using the HTTP version.</p> |
| <h2 id="from-your-application">From your application</h2> |
| <p>The <code>QueryExecutionHTTP</code> has methods for creating a |
| <code>QueryExecution</code> object for remote use. There are various |
| HTTP specific settings; the default should work in most cases.</p> |
| <p>The remote request is made when the <code>execSelect</code>, <code>execConstruct</code>, |
| <code>execDescribe</code> or <code>execAsk</code> method is called.</p> |
| <p>The results are held locally after remote execution and can be |
| processed as usual.</p> |
| <h2 id="from-the-command-line">From the command line</h2> |
| <p>The <a href="cmds.html#arq.rsparql"><code>arq.rsparql</code> command</a> can issue remote |
| query requests using the <code>--service</code> argument:</p> |
| <pre><code>java -cp ... arq.rsparql --service 'http://host/service' --query 'SELECT ?s WHERE {?s [] []}' |
| </code></pre> |
| <p>Or: |
| rsparql –service ‘http://host/service’ –query ‘SELECT ?s WHERE {?s [] []}’</p> |
| <p>This takes a URL that is the service location.</p> |
| <p>The query given is parsed locally to check for syntax errors before |
| sending.</p> |
| <h2 id="authentication">Authentication</h2> |
| <p>ARQ provides a flexible API for authenticating against remote services, see the <a href="../sparql-apis/http-auth.html">HTTP Authentication</a> documentation for more details.</p> |
| <h2 id="firewalls-and-proxies">Firewalls and Proxies</h2> |
| <p>Don’t forget to set the proxy for Java if you are accessing a |
| public server from behind a blocking firewall. Most home firewalls |
| do not block outgoing requests; many corporate firewalls do block |
| outgoing requests.</p> |
| <p>If, to use your web browser, you need to set a proxy, you need to |
| do so for a Java program.</p> |
| <p>Simple examples include:</p> |
| <pre><code>-DsocksProxyHost=YourSocksServer |
| |
| -DsocksProxyHost=YourSocksServer -DsocksProxyPort=port |
| |
| -Dhttp.proxyHost=WebProxy -Dhttp.proxyPort=Port |
| </code></pre> |
| <p>This can be done in the application |
| <em>if it is done before any network connection are made</em>:</p> |
| <pre><code> System.setProperty("socksProxyHost", "socks.corp.com"); |
| </code></pre> |
| <p>Consult the Java documentation for more details. Searching the web |
| is also very helpful.</p> |
| <p><a href="index.html">ARQ documentation index</a></p> |
| |
| </article> |
| |
| <aside class="text-muted align-self-start mb-3 mb-xl-5 p-0 d-none d-xl-flex flex-column sticky-top"> |
| <h2 class="h6 sticky-top m-0 p-2 bg-body-tertiary">On this page</h2> |
| <nav id="TableOfContents"> |
| <ul> |
| <li><a href="#from-your-application">From your application</a></li> |
| <li><a href="#from-the-command-line">From the command line</a></li> |
| <li><a href="#authentication">Authentication</a></li> |
| <li><a href="#firewalls-and-proxies">Firewalls and Proxies</a></li> |
| </ul> |
| </nav> |
| </aside> |
| </main> |
| |
| </div> |
| </div> |
| </div> |
| |
| <footer class="bd-footer py-4 py-md-5 mt-4 mt-lg-5 bg-body-tertiary"> |
| <div class="container" style="font-size:80%" > |
| <p> |
| Copyright © 2011–2024 The Apache Software Foundation, Licensed under the |
| <a href="https://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>. |
| </p> |
| <p> |
| Apache Jena, Jena, the Apache Jena project logo, Apache and the Apache feather logos are trademarks of |
| The Apache Software Foundation. |
| <br/> |
| <a href="https://privacy.apache.org/policies/privacy-policy-public.html" |
| >Apache Software Foundation Privacy Policy</a>. |
| </p> |
| </div> |
| </footer> |
| |
| <script src="/js/popper.min.js.js" type="text/javascript"></script> |
| <script src="/js/bootstrap.min.js" type="text/javascript"></script> |
| <script src="/js/improve.js" type="text/javascript"></script> |
| |
| <script type="text/javascript"> |
| (function() { |
| 'use strict' |
| |
| |
| |
| const links = document.querySelectorAll(`a[href="${window.location.pathname}"]`) |
| if (links !== undefined && links !== null) { |
| for (const link of links) { |
| |
| link.classList.add('active') |
| let parentElement = link.parentElement |
| let count = 0 |
| const levelsLimit = 4 |
| |
| |
| |
| |
| |
| while (['UL', 'LI'].includes(parentElement.tagName) && count <= levelsLimit) { |
| if (parentElement.tagName === 'LI') { |
| |
| |
| |
| parentElement.querySelector('a:first-child').classList.add('active') |
| } |
| parentElement = parentElement.parentElement |
| count++ |
| } |
| } |
| } |
| })() |
| </script> |
| |
| </body> |
| </html> |
