javax.mail.Service
выполняет connect()
подключение к указанному хосту и порту.Там он использует javax.mail.Authenticator
для аутентификации.
Код из javax.mail.Service.connect()
метод:
public synchronized void connect(String host, int port,
String user, String password) throws MessagingException {
// see if the service is already connected
if (isConnected())
throw new IllegalStateException("already connected");
PasswordAuthentication pw;
boolean connected = false;
boolean save = false;
String protocol = null;
String file = null;
// get whatever information we can from the URL
// XXX - url should always be non-null here, Session
// passes it into the constructor
if (url != null) {
protocol = url.getProtocol();
if (host == null)
host = url.getHost();
if (port == -1)
port = url.getPort();
if (user == null) {
user = url.getUsername();
if (password == null) // get password too if we need it
password = url.getPassword();
} else {
if (password == null && user.equals(url.getUsername()))
// only get the password if it matches the username
password = url.getPassword();
}
file = url.getFile();
}
// try to get protocol-specific default properties
if (protocol != null) {
if (host == null)
host = session.getProperty("mail." + protocol + ".host");
if (user == null)
user = session.getProperty("mail." + protocol + ".user");
}
// try to get mail-wide default properties
if (host == null)
host = session.getProperty("mail.host");
if (user == null)
user = session.getProperty("mail.user");
// try using the system username
if (user == null) {
try {
user = System.getProperty("user.name");
} catch (SecurityException sex) {
if (debug)
sex.printStackTrace(session.getDebugOut());
}
}
// if we don't have a password, look for saved authentication info
if (password == null && url != null) {
// canonicalize the URLName
setURLName(new URLName(protocol, host, port, file, user, null));
pw = session.getPasswordAuthentication(getURLName());
if (pw != null) {
if (user == null) {
user = pw.getUserName();
password = pw.getPassword();
} else if (user.equals(pw.getUserName())) {
password = pw.getPassword();
}
} else
save = true;
}
// try connecting, if the protocol needs some missing
// information (user, password) it will not connect.
// if it tries to connect and fails, remember why for later.
AuthenticationFailedException authEx = null;
try {
connected = protocolConnect(host, port, user, password);
} catch (AuthenticationFailedException ex) {
authEx = ex;
}
// if not connected, ask the user and try again
if (!connected) {
InetAddress addr;
try {
addr = InetAddress.getByName(host);
} catch (UnknownHostException e) {
addr = null;
}
pw = session.requestPasswordAuthentication(
addr, port,
protocol,
null, user);
if (pw != null) {
user = pw.getUserName();
password = pw.getPassword();
// have the service connect again
connected = protocolConnect(host, port, user, password);
}
}
// if we're not connected by now, we give up
if (!connected) {
if (authEx != null)
throw authEx;
else if (user == null)
throw new AuthenticationFailedException(
"failed to connect, no user name specified?");
else if (password == null)
throw new AuthenticationFailedException(
"failed to connect, no password specified?");
else
throw new AuthenticationFailedException("failed to connect");
}
setURLName(new URLName(protocol, host, port, file, user, password));
if (save)
session.setPasswordAuthentication(getURLName(),
new PasswordAuthentication(user, password));
// set our connected state
setConnected(true);
// finally, deliver the connection event
notifyConnectionListeners(ConnectionEvent.OPENED);
}