title: errors while connecting java with sql server 2017
body: <pre><code>public class RDF2Connection {
  
       static Connection connection=null;
       final static String connectionUrl = "jdbc:sqlserver://DESKTOP-Q5K9FE6:1433;" +
               "databaseName=RDFDB;";
      public static Connection getRdf2Connected(){
  
              try {
                  Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
                  connection = DriverManager.getConnection(connectionUrl, "sa", "root");
              } catch (ClassNotFoundException e) {
                  e.printStackTrace();
              } catch (SQLException e) {
                  e.printStackTrace();
              }
              return connection;
          }
  
  }
  </code></pre>
  
  <hr>
  
  <blockquote>
    <p>com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection
    to the host DESKTOP-Q5K9FE6, port 1433 has failed. Error: "Connection
    refused: no further information. Verify the connection properties.
    Make sure that an instance of SQL Server is running on the host and
    accepting TCP/IP connections at the port. Make sure that TCP
    connections to the port are not blocked by a firewall.".
          at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:206)
          at com.microsoft.sqlserver.jdbc.SQLServerException.ConvertConnectExceptionToSQLServerException(SQLServerException.java:257)
          at com.microsoft.sqlserver.jdbc.SocketFinder.findSocket(IOBuffer.java:2385)
          at com.microsoft.sqlserver.jdbc.TDSChannel.open(IOBuffer.java:567)
          at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1955)
          at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:1616)
          at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:1447)
          at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:788)
          at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:1187)
          at java.sql.DriverManager.getConnection(DriverManager.java:664)
          at java.sql.DriverManager.getConnection(DriverManager.java:247)
          at com.rdf2.databaseconnection.RDF2Connection.getRdf2Connected(RDF2Connection.java:22)
          at MainClass.main(MainClass.java:53)
        java.lang.NullPointerException
          at MainClass.main(MainClass.java:54)</p>
    
    <p>Process finished with exit code 0</p>
  </blockquote>