Connecting Virtuoso to NodeJS via JDBC

Question

I have the following code to connect to a Virtuoso 7 Server through Node and JDBC (via jdbc package on npm):

    const checkDatabaseConnection = function(callback)
{
    const JDBC = require('jdbc');
    const jinst = require('jdbc/lib/jinst');

    if (!jinst.isJvmCreated()) {
        jinst.addOption("-Xrs");
        jinst.setupClasspath([
            Pathfinder.absPathInApp("conf/virtuoso-jdbc/virtjdbc4.jar")
        ]);
    }

    const config = {
        // Required
        url : "jdbc:virtuoso://192.168.56.249:1111",
        drivername: 'virtuoso.jdbc4.Driver',
        minpoolsize: 1,
        maxpoolsize: 100,
        maxidle : 5000,
        username : "dba",
        password : "dba",

        properties: {}
    };

    const jdbcdb = new JDBC(config);

    jdbcdb.initialize(function(err) {
        if (err) {
            console.log(err);
        }
    });
};

It immediately returns:

{ Error: Error running static method
virtuoso.jdbc4.VirtuosoException: Virtuoso Communications Link Failure (timeout) : Connection to the server lost
    at virtuoso.jdbc4.VirtuosoFuture.nextResult(VirtuosoFuture.java:63)
    at virtuoso.jdbc4.VirtuosoConnection.connect(VirtuosoConnection.java:328)
    at virtuoso.jdbc4.VirtuosoConnection.connect(VirtuosoConnection.java:224)
    at virtuoso.jdbc4.VirtuosoConnection.<init>(VirtuosoConnection.java:169)
    at virtuoso.jdbc4.Driver.connect(Driver.java:58)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:208)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
 cause: nodeJava_virtuoso_jdbc4_VirtuosoException {} }

Running Virtuoso JDBC driver 4.2, Virtuoso 7.

I did telnet to the server on the same IP and port, and the server is listening. What could be the problem?

Please post the full Java exception stacktrace. Likely it simply can't connect because, the server isn't running on 192.168.56.249:1111, or your host is not allowed to connect. — Mark Rotteveel, Sep 30 '17 at 08:39
I will post the stack trace. Server is listening because it responds to telnet in that port. — João Rocha da Silva, Sep 30 '17 at 08:43
I don't know Virtuoso, but the exception suggests it isn't responding or not finishing the connection handshake. This could still suggest that it isn't Virtuoso listening on port 1111, but something else. — Mark Rotteveel, Sep 30 '17 at 11:53
Did you run your `telnet` test from the same client environment as where `node.js` is running? Are you running Virtuoso Open Source or Enterprise Edition? Are all components (Virtuoso, JDBC driver, etc.) current/latest version (`java virtuoso.jdbc4.Driver`, `virtuoso-t -?`, `virtuoso-iodbc-t -?`)? — TallTed, Sep 30 '17 at 17:30
Did you resolve this? If so, what was the issue? If not, can you provide the additional info requested above? — TallTed, Oct 19 '17 at 15:46

score 1 · Answer 1 · answered Mar 13 '19 at 20:50

1) Check the reference node-jdbc The the config property username is wrong, it must me user

2) The next example works properly for me.

var JDBC = require('jdbc');
var jinst = require('jdbc/lib/jinst');
var asyncjs = require('async');

if (!jinst.isJvmCreated()) {
  jinst.addOption("-Xrs");
  jinst.setupClasspath(['./drivers/virtjdbc4.jar']);
}

const config = {
     // Required
     url : "jdbc:virtuoso://192.168.10.101:1111",
     drivername: 'virtuoso.jdbc4.Driver',
     minpoolsize: 1,
     maxpoolsize: 100,
     maxidle : 5000,
     user : "dba",
     password : "dba",

     properties: {}
 };

 const jdbcdb = new JDBC(config);

 jdbcdb.initialize(function(err) {
     if (err) {
         console.log(err);
     }
 });

jdbcdb.reserve(function(err, connObj) {
  if (connObj) {
    console.log("Using connection: " + connObj.uuid);
    var conn = connObj.conn;

    asyncjs.series([
      function(callback) {
        console.log("call create Statement");

        conn.createStatement(function(err, statement) {
          if (err) {
            callback(err);
          } else {
            console.log("execute query");

            statement.executeQuery("SELECT * FROM Demo.demo.Artist",
                                   function(err, resultset) {
              if (err) {
                callback(err)
              } else {
                resultset.toObjArray(function(err, results) {
                  console.log('res='+JSON.stringify(results));
                  if (results.length > 0) {
                    console.log("Name: " + results[0].Name);
                  }
                  callback(null, resultset);
                });
              }
            });
          }
        });
      }
    ], function(err, results) {
      // Release the connection back to the pool.
      if (err) 
        console.log("Error:"+err);

      jdbcdb.release(connObj, function(err) {
        if (err) {
          console.log(err.message);
        }
      });
    });
  }
});

The output log:

Using connection: f5c60576-1da5-4129-af0a-f25d10160f21
call create Statement
execute query
res=[{"ArtistID":1,"CountryCode":"nl","Name":"Rembrandt Harmenszoon van Rijn"}]
Name: Rembrandt Harmenszoon van Rijn

Connecting Virtuoso to NodeJS via JDBC

1 Answers1