function conn = connect(hostname, database, username, password)
% CONNECT Opens a connection to the given database.
%
% CALL:
%
%   conn = utils.mysql.connect(hostname, database, username, password)
%
% This function returns a Java object implementing the java.sql.Connection
% interface connected to the given database using the provided credentials.
% If the connection fails because the given username and password pair is not
% accepted by the server an utils:mysql:connect:AccessDenied error is thrown.
%

  % informative message
  import utils.const.*
  utils.helper.msg(msg.PROC1, 'connection to mysql://%s/%s username=%s', hostname, database, username);

  % connection credential
  uri = sprintf('jdbc:mysql://%s/%s', hostname, database);
  db = javaObject('com.mysql.jdbc.Driver');
  pl = javaObject('java.util.Properties');
  pl.setProperty(db.USER_PROPERTY_KEY, username);
  pl.setProperty(db.PASSWORD_PROPERTY_KEY, password);

  try
    % connect
    conn = db.connect(uri, pl);
  catch ex
    % haven't decided yet if this code should be here or higher in the stack
    if strcmp(ex.identifier, 'MATLAB:Java:GenericException')
      % exceptions handling in matlab sucks
      if ~isempty(strfind(ex.message, 'java.sql.SQLException: Access denied'))
        throw(MException('utils:mysql:connect:AccessDenied', '### access denied').addCause(ex));
      end
    end
    rethrow(ex);
  end
end
