Store graph in virtuoso via HTTP Graph Store Protocol

VirtuosoStorage.scala

    def storeGraphGraphProtocol(graphURI: String, graph: Graph){
        val httpSuffix = if(endpointUsesSSL){"s"}else{""}
        val requestUri = String.format("http%s://%s:%s/sparql-graph-crud-auth?graph-uri=%s", httpSuffix, server, endpointPort.toString, graphURI)

        val creds = new UsernamePasswordCredentials(sqlUsername, sqlPassword)
        val httpclient = new DefaultHttpClient()
        val post = new HttpPost(requestUri)
        post.addHeader("X-Requested-Auth", "Digest")
        post.addHeader("Content-Type", "application/xml")
        try {

            httpclient.getCredentialsProvider().setCredentials(AuthScope.ANY, creds)
            val stringEntity = new StringEntity( graph.toStringRepresentation(RdfRepresentation.RdfXml) , "UTF-8")
            stringEntity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, "application/xml"))
            post.setEntity(stringEntity)
            httpclient.execute(post)
        } finally {
            httpclient.getConnectionManager().shutdown()
        }
    }