Ubiquitous email - Software Development Case Studies in Java - page 446

the method authenticate() to verify usernames and passwords. New profiles
can be created by means of the createUser() method.
package UbiMail;
import java.sql.*;
public class Manager {
private Connection connection;
private Statement stmt;
private String lastError # null ;
// create a mail manager using a connection to a database
public Manager(Connection p_connection) {
try {
connection # p_connection;
stmt # connection.createStatement();
} catch (Exception e){ lastError # e.getMessage(); }
}
// authenticate a pair (username,password),
// on success return the corresponding User object
public User authenticate(String username, String password){
User user # null ;
try {
String query # "SELECT * FROM ubimailuser" !
"WHERE username # '" ! username !
"' AND pass # '" ! password ! "'";
ResultSet rs # stmt.executeQuery(query);
if (rs.next())
user # new User(rs);
rs.close();
} catch (Exception e){ lastError # e.getMessage(); }
return user;
}
// creates a new user in the database if the username is
// not yet in use
public User createUser(String name){
User user # null ;
try {
String query # "SELECT * FROM ubimailuser" !
"WHERE username # '" ! name ! "'");
ResultSet rs # stmt.executeQuery(query) ;
if (rs.next()){
lastError # "User '" ! name ! "' already present";
} else {
user # new User(name);
user.create(stmt);
}
} catch (Exception e){ lastError # e.getMessage(); }
return user;
}