Exception in thread "main" java.lang.ClassNotFoundException: com.microsoft.sqlserver.jdbc.SQLServerDriver
    at java.net.URLClassLoader$ 1 .run(URLClassLoader.java: 200 )
    at java.security.AccessController.doPrivileged( Native  Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java: 188 )
    at java.lang.ClassLoader.loadClass(ClassLoader.java: 306 )
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java: 268 )
    at java.lang.ClassLoader.loadClass(ClassLoader.java: 251 )
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java: 319 )
    at java.lang. Class .forName0( Native  Method)
    at java.lang. Class .forName( Class .java: 164 )
    at conn.main(conn.java: 36 )

      public   class  connect{
      private  java.sql.Connection  con =  null ;
      private   final  String url = "jdbc:microsoft:sqlserver://";
      private   final  String serverName= "127.0.0.1";
      private   final  String portNumber = "1433";
      private   final  String databaseName= "maindatabase";
      private   final  String userName = "sa";
      private   final  String password = "sa";
     // Informs the driver to use server a side-cursor, 
     // which permits more than one active statement 
     // on a connection.
      private   final  String selectMethod = "cursor"; 
     
     // Constructor
      public  connect(){}
     
      private  String getConnectionUrl(){
           return  url+serverName+":"+portNumber+";databaseName="+databaseName+";selectMethod="+selectMethod+";";
     }
     
      private  java.sql.Connection getConnection(){
           try {
                Class .forName("com.microsoft.jdbc.sqlserver.SQLServerDriver"); 
               con = java.sql.DriverManager.getConnection(getConnectionUrl(),userName,password);
                if (con!= null ) System.out.println("Connection Successful!");
          } catch (Exception e){
               e.printStackTrace();
               System.out.println("Error Trace in getConnection() : " + e.getMessage());
         }
           return  con;
      }