Establishing postgresql jdbc connection

The java code establishes postgresql database connection .

import java.sql.*;
import java.text.*;
import java.io.*;
//class
public class BioappAPI
{

   Connection       db;
   DatabaseMetaData dbmd;

   /** 

     * The constructor of BioApp API class It establishes connection with the database
     * and intitializes the class variables
     * @param  argv  a String array that contains database name,username and password
   */

   //Constructor
   public BioappAPI(String argv[])
    throws ClassNotFoundException, SQLException
   {
      String database = argv[0];
      String username = argv[1];
      String password = argv[2];
      try
      {
          Class.forName("org.postgresql.Driver");
          db = DriverManager.getConnection("jdbc:postgresql:"+database,username,password);
          dbmd = db.getMetaData();
          System.out.println("Connection to "+dbmd.getDatabaseProductName()+" "+
          dbmd.getDatabaseProductVersion()+" successful.
");
       }//end of try
       catch(Exception e)
       {
           e.printStackTrace() ;
           System.out.println("
 Connection could not be established!");
       }
   }//end of constructor

}//end of class