据我所知，您要实现的目标没有概念上的问题。 现在，根据错误，我认为这可能与您针对rest api restapp.get('/getallIDs',function(req,res) {...}执行的GET请求有关 您可以确认repository.query（payload）调用返回正确的响应吗？我想您可以简单地将记录器放在stream.on（'data'）之前，看看是否已打印，这将确认graphdbjs请求可能是正确的。 我可以给您一个稍微改进但仍然相似的示例，该示例似乎可以正确传输查询结果：

const {ServerClient,ServerClientConfig} = require('graphdbjs').server;
const {RepositoryClientConfig} = require('graphdbjs').repository;
const {RDFMimeType} = require('graphdbjs').http;
const {SparqlJsonResultParser} = require('graphdbjs').parser;
const {GetQueryPayload,QueryType} = require('graphdbjs').query;

const serverConfig = new ServerClientConfig('http://localhost:7200/',{
    'Accept': RDFMimeType.SPARQL_RESULTS_JSON
});
const server = new ServerClient(serverConfig);
const readTimeout = 30000;
const writeTimeout = 30000;
const repositoryClientConfig = new RepositoryClientConfig(['http://localhost:7200/repositories/testrepo'],{},'',readTimeout,writeTimeout);

server.getRepository('testrepo',repositoryClientConfig).then(function(repository) {  

    console.log('REPO:',repository);
    repository.registerParser(new SparqlJsonResultParser());

    const payload = new GetQueryPayload()
        .setQuery('select * where {?s ?p ?o}')
        .setQueryType(QueryType.SELECT)
        .setResponseType(RDFMimeType.SPARQL_RESULTS_JSON)
        .setLimit(100);
    return repository.query(payload);

})
.then(function(stream) {
    console.log('SELECT:');
    stream.on('data',function(bindings) {
        var test = Object.values(bindings);
        console.log('DATA');
        // var element = {id: test[0].id.replace(/['"]+/g,''),name: test[1].id.replace(/['"]+/g,'')}
    });
    stream.on('end',function() {
        console.log('END');
        // restapp.get('/getallIDs',res)  {
        //     res.send(element);
        // });
        // restapp.listen(3000,function () {
        //     console.log('App listening on port 3000!');
        // });
    });
})
.catch(function(error) {
    console.log('ERROR',error);
});

您可以解决的另一件事是res.send(element);调用，正如我所见，由于undefined的作用范围是element回调，因此实际上将发送stream.on('data'。因此，您可以通过在var element;行之前定义stream.on('data'来使其可用。

最好的结构化方法是拥有不同的文件，其中一个是主节点app.js

    var express = require('express');
var restapp = express();
var queryController = require('./controllers/queryController')

restapp.use(queryController)

restapp.listen(3001,function () {
    console.log('Αpp listening on port 3001!');
});

并暗示您导入了queryController.js，其中包括对graphdb服务器执行所需的每个不同查询的代码

var express = require('express');
var router = express.Router()

const {ServerClient,ServerClientConfig} = require('graphdb').server;
const {RDFMimeType} = require('graphdb').http;
const {RepositoryClientConfig} = require('graphdb').repository;
const {SparqlJsonResultParser} = require('graphdb').parser;
const {GetQueryPayload} = require('graphdb').query;
const {QueryType}= require('graphdb').query;
const serverConfig = new ServerClientConfig('http://localhost:7200',{
    'Accept': RDFMimeType.SPARQL_RESULTS_JSON
});

router.get('/hi',(req,res) => {
      res.send('hi')
})



router.get('/getallids',res) => {
    head = {};
    table = [];
    head.table = table;
    const server = new ServerClient(serverConfig);
    const readTimeout = 30000;
    const writeTimeout = 30000;
    const repositoryClientConfig = new RepositoryClientConfig(['http://localhost:7200/repositories/V2'],writeTimeout);
    server.getRepository('V2',repositoryClientConfig).then(repository => {  
        repository.registerParser(new SparqlJsonResultParser());     
        const payload = new GetQueryPayload()
        .setQuery('select * where {?p ?o ?k}')
        .setQueryType(QueryType.SELECT)
        .setResponseType(RDFMimeType.SPARQL_RESULTS_JSON)
        .setLimit(100);
        repository.query(payload).then((stream) => {
                stream.on('data',(bindings) => {
                var test = Object.values(bindings);
                var i=0;
                test.forEach(function(key,value){
                    test2 = Object.values(key);
                    if (i%2==1){
                    return true;}
                    var element = {id: test[0].id.replace(/['"]+/g,'')}
                    i++;
                    head.table.push(element);
                });       
            });
            stream.on('end',() => {  
                    res.send(head);   
            });       
        }).catch(err => console.log(err));
    });
})


router.get('/getid/:id',res) => {
    const params = req.params;
    head = {};
    table = [];
    head.table = table;
    const server = new ServerClient(serverConfig);
    const readTimeout = 30000;
    const writeTimeout = 30000;
    const repositoryClientConfig = new RepositoryClientConfig(['http://localhost:7200/repositories/V2'],repositoryClientConfig).then(repository => {  
        repository.registerParser(new SparqlJsonResultParser());     
        const payload = new GetQueryPayload()
        .setQuery('select'+Object.values(params)+'where {?p ?o ?k}')
        .setQueryType(QueryType.SELECT)
        .setResponseType(RDFMimeType.SPARQL_RESULTS_JSON)
        .setLimit(100);
        repository.query(payload).then((stream) => {
                stream.on('data',value){
                    test2 = Object.values(key);
                    if (i%2==1){
                    return true;}
                    var element = {key: test[0].id.replace(/['"]+/g,value: test[1].id.replace(/['"]+/g,() => {
                    res.send(head);  
            });       
        }).catch(err2 => console.log(err2));
    });
})
module.exports = router;