Simple SPARQL Endpoint Proxy Servlet

Sparql Endpoint Proxy Servlet - Helps for bypassing CORS issues.

Simple proxy that redirects all elements in the request to a configured SPARQL endpoint. Headers in the request are also redirected.

Configuring the proxy

The only setting required to configure the SPARQL Endpoint proxy is proxy.host which refers to the host:port info in which the Stardog HTTP service is running, for example:

<init-param>
	<param-name>proxy.host</param-name>
	<param-value>http://localhost:5822</param-value>
</init-param>

The previous indicats the a Stardog DB is running the HTTP protocol in http://localhost:5822, which can be modified to any other information, either a local reference or remote.

Building .war file with Ant

To build the proxy war, just execute:

ant clean web-dist

This will generate the sparql-proxy.war file that you just need to copy to your app container webapps directory.

Using the proxy

To use the proxy, simple send the request to it, following the same pattern as you would do with a Stardog DB directly. For instance, to query the DB gov directly to Stardog HTTP endpoint you'll do:

curl -X GET "http://localhost:5822/gov/query?query=select%20*%20where%20%7B%20%3Fs%20%3Fp%20%3Fo%20%7D%20limit%2010"

Using the proxy (with CORS support), the same can be done:

curl -X GET "http://localhost:8181/sparql-proxy/gov/query?query=select%20*%20where%20%7B%20%3Fs%20%3Fp%20%3Fo%20%7D%20limit%2010"

where:

• http://localhost:8181/sparql-proxy is the path for the sparql-proxy (with servlet containter running in port 8181)
• gov is the Stardog DB
• query?query= points to the encoded query.