The TCP/IP connection to the host localhost, port 1433 has failed. Error: "connect timed out. "

Question

This is my Java code:

import java.sql.*;
public class Database_connect 
{
  public static void main(String[] args) {
    String url= "jdbc:sqlserver://localhost:1433;DatabaseName=Reena;instance=SQLSERVER;encrypt=true;TrustServerCertificate=true";
    try{

        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
        System.out.println("Driver added");
        Connection con=DriverManager.getConnection(url,"sa","Reena123");
        System.out.println("connection established.");
        con.close();
    }
    catch(ClassNotFoundException e)
    {
        System.out.println("Driver not loaded");
    }
   catch(SQLException e)
   {
       System.out.println("Not connected."+e.getMessage());
   }
  }    
}

I have checked all these things that are mentioned in error.
But it's still giving me this error:

The TCP/IP connection to the host localhost, port 1433 has failed.
Error: “connect timed out. ”

What can I do to fix this?