My 1st JDBC and PostgreSQL

Following the example in :
https://www.tutorialspoint.com/postgresql/postgresql_java.htm
I wrote the bellow method :

public void connectToDatabase() throws ClassNotFoundException, 
SQLException {
         try {
             this.perr(this.getDatabaseClass()); // 
org.postgresql.Driver = Class
             this.perr(this.getDatabaseUrl());   // 
jdbc:postgresql://localhost:5432/sara.pgdb = url
             this.perr(this.getUserID());        // chispa = user
             this.perr(this.getUserPassword());  // 8UUKZW = password

             Class.forName(this.getDatabaseClass().toString());
             conn = 
DriverManager.getConnection(this.getDatabaseUrl().toString(),
                     this.getUserID().toString(),
                     this.getUserPassword().toString() );
         } catch (final SQLException | ClassNotFoundException e) {
             throw e;
         }
     }

However, it throws an exception that reads :
Exception in thread "main" org.postgresql.util.PSQLException: FATAL: 
database "sara.pgdb" does not exist

In reference to the above web page, it reads :
The following Java code shows how to connect to an existing database. If 
the database does not exist, then it will be created and finally a 
database object will be returned.

True, the database file does not exist, but isn't JDBC supposed to 
create it?


Any help would be much appreciated.