public class ConnectDatabase {
   ConnectDatabase(String username, String password , String a) throws SQLException  {
       Connection con = DriverManager.getConnection("jdbc:derby://localhost:1527/ai", username, password);
       Statement stmt =  con.createStatement();    // ResultSet FromResultSet = stmt.executeQuery("SELECT * FROM *");
       ArrayList<String> TableName=new ArrayList<>();
       DatabaseMetaData md   = con.getMetaData();
       ResultSet rs = md.getTables(null, null, "%", null);
       while (rs.next()){
       TableName.add(rs.getString(3));

     }
       String[] Tablenames= new String[TableName.size()];
       String[] TableNames = TableName.toArray(Tablenames);

System.out.println("Database checking done!");
con.close();
}

public String[] getTableNames(String username, String password , String a) throws SQLException{
 Connection DatabaseConnection = DriverManager.getConnection("jdbc:derby://localhost:1527/ai", username, password);
     DatabaseMetaData DatabaseInfo   = DatabaseConnection.getMetaData();
      ResultSet FromResultSet = DatabaseInfo.getTables(null, null, "%", null);
      ArrayList<String> TableNameArrayList=new ArrayList<>();

      while (FromResultSet.next()){
         TableNameArrayList.add(FromResultSet.getString(3));

     }
     String[] StringArrayObject= new String[TableNameArrayList.size()];
      String[] TableNameStringArray = TableNameArrayList.toArray(StringArrayObject);
    DatabaseConnection.close();
      return TableNameStringArray;

 }
}