proxy.js

const express = require('express');
const fetch = (...args) => import('node-fetch').then(({default: fetch}) => fetch(...args));
const app = express();

app.use(express.json());
app.use(express.static('.'));

const RDF4J = 'http://localhost:8080/rdf4j-server/repositories/grafexamen';

app.get('/statiuni', async (req, res) => {
    const query = `
        PREFIX ex: <http://example.org/statiuni/>
        SELECT ?nume ?tara ?an WHERE {
            ?s a ex:Statiune ;
               ex:nume ?nume ;
               ex:tara ?tara ;
               ex:anInaugurare ?an .
        }
    `;
    const response = await fetch(`${RDF4J}?query=${encodeURIComponent(query)}`, {
        headers: { 'Accept': 'application/sparql-results+json' }
    });
    const data = await response.json();
    res.json(data);
});

app.get('/plaje', async (req, res) => {
    const statiune = req.query.statiune;
    const query = `
        PREFIX ex: <http://example.org/statiuni/>
        SELECT ?numeStatiune ?numePlaja ?lungime ?tip WHERE {
            ?p a ex:Plaja ;
               ex:nume ?numePlaja ;
               ex:lungime ?lungime ;
               ex:tip ?tip ;
               ex:apartineDe ?s .
            ?s ex:nume ?numeStatiune .
            FILTER(?numeStatiune = "${statiune}")
        }
    `;
    const response = await fetch(`${RDF4J}?query=${encodeURIComponent(query)}`, {
        headers: { 'Accept': 'application/sparql-results+json' }
    });
    const data = await response.json();
    res.json(data);
});

app.post('/adauga-plaja', async (req, res) => {
    const { numePlaja, lungime, tip, numeStatiune } = req.body;
    const update = `
        PREFIX ex: <http://example.org/statiuni/>
        PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
        INSERT DATA {
            ex:${numePlaja.replace(/\s+/g, '')} a ex:Plaja ;
                ex:nume "${numePlaja}" ;
                ex:lungime "${lungime}"^^xsd:decimal ;
                ex:tip "${tip}" ;
                ex:apartineDe ?s .
        }
    `;
    const statiuneQuery = `
        PREFIX ex: <http://example.org/statiuni/>
        SELECT ?s WHERE { ?s ex:nume "${numeStatiune}" . }
    `;
    const statiuneResp = await fetch(`${RDF4J}?query=${encodeURIComponent(statiuneQuery)}`, {
        headers: { 'Accept': 'application/sparql-results+json' }
    });
    const statiuneData = await statiuneResp.json();
    const statiuneURI = statiuneData.results.bindings[0].s.value;

    const insertQuery = `
        PREFIX ex: <http://example.org/statiuni/>
        PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
        INSERT DATA {
            ex:${numePlaja.replace(/\s+/g, '')} a ex:Plaja ;
                ex:nume "${numePlaja}" ;
                ex:lungime "${lungime}"^^xsd:decimal ;
                ex:tip "${tip}" ;
                ex:apartineDe <${statiuneURI}> .
        }
    `;
    await fetch(`${RDF4J}/statements`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/sparql-update' },
        body: insertQuery
    });
    res.json({ succes: true });
});

app.listen(5000, () => console.log('Proxy pornit pe http://localhost:5000'));