UsernamePasswordToken token = new UsernamePasswordToken(loginForm.getUsername(), loginForm.getPassphrase());
token.setRememberMe(true);Subject currentUser = SecurityUtils.getSubject();currentUser.login(token);

 public void login(AuthenticationToken token) throws AuthenticationException {clearRunAsIdentitiesInternal();Subject subject = securityManager.login(this, token);PrincipalCollection principals;String host = null;if (subject instanceof DelegatingSubject) {DelegatingSubject delegating = (DelegatingSubject) subject;//we have to do this in case there are assumed identities - we don't want to lose the 'real' principals:principals = delegating.principals;host = delegating.host;} else {principals = subject.getPrincipals();}if (principals == null || principals.isEmpty()) {String msg = "Principals returned from securityManager.login( token ) returned a null or " +"empty value.  This value must be non null and populated with one or more elements.";throw new IllegalStateException(msg);}this.principals = principals;this.authenticated = true;if (token instanceof HostAuthenticationToken) {host = ((HostAuthenticationToken) token).getHost();}if (host != null) {this.host = host;}Session session = subject.getSession(false);if (session != null) {this.session = decorate(session);} else {this.session = null;}}

    public Subject login(Subject subject, AuthenticationToken token) throws AuthenticationException {AuthenticationInfo info;try { info = authenticate(token);} catch (AuthenticationException ae) {try {onFailedLogin(token, ae, subject);} catch (Exception e) {if (log.isInfoEnabled()) {log.info("onFailedLogin method threw an " +"exception.  Logging and propagating original AuthenticationException.", e);}}throw ae; //propagate
        }  Subject loggedIn = createSubject(token, info, subject); onSuccessfulLogin(token, info, loggedIn);return loggedIn;}

    /*** Delegates to the wrapped {@link org.apache.shiro.authc.Authenticator Authenticator} for authentication.*/public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {return this.authenticator.authenticate(token);}

public final AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {if (token == null) {throw new IllegalArgumentException("Method argumet (authentication token) cannot be null.");}log.trace("Authentication attempt received for token [{}]", token);AuthenticationInfo info;try { info = doAuthenticate(token);if (info == null) {String msg = "No account information found for authentication token [" + token + "] by this " +"Authenticator instance.  Please check that it is configured correctly.";throw new AuthenticationException(msg);}} catch (Throwable t) {AuthenticationException ae = null;if (t instanceof AuthenticationException) {ae = (AuthenticationException) t;}if (ae == null) {//Exception thrown was not an expected AuthenticationException.  Therefore it is probably a little more//severe or unexpected.  So, wrap in an AuthenticationException, log to warn, and propagate:String msg = "Authentication failed for token submission [" + token + "].  Possible unexpected " +"error? (Typical or expected login exceptions should extend from AuthenticationException).";ae = new AuthenticationException(msg, t);}try {notifyFailure(token, ae);} catch (Throwable t2) {if (log.isWarnEnabled()) {String msg = "Unable to send notification for failed authentication attempt - listener error?.  " +"Please check your AuthenticationListener implementation(s).  Logging sending exception " +"and propagating original AuthenticationException instead...";log.warn(msg, t2);}}throw ae;}log.debug("Authentication successful for token [{}].  Returned account [{}]", token, info);notifySuccess(token, info);return info;}

    protected AuthenticationInfo doAuthenticate(AuthenticationToken authenticationToken) throws AuthenticationException {assertRealmsConfigured();Collection<Realm> realms = getRealms();if (realms.size() == 1) {return doSingleRealmAuthentication(realms.iterator().next(), authenticationToken);} else {return doMultiRealmAuthentication(realms, authenticationToken);}}

    /*** Performs the authentication attempt by interacting with the single configured realm, which is significantly* simpler than performing multi-realm logic.** @param realm the realm to consult for AuthenticationInfo.* @param token the submitted AuthenticationToken representing the subject's (user's) log-in principals and credentials.* @return the AuthenticationInfo associated with the user account corresponding to the specified {@code token}*/protected AuthenticationInfo doSingleRealmAuthentication(Realm realm, AuthenticationToken token) {if (!realm.supports(token)) {String msg = "Realm [" + realm + "] does not support authentication token [" +token + "].  Please ensure that the appropriate Realm implementation is " +"configured correctly or that the realm accepts AuthenticationTokens of this type.";throw new UnsupportedTokenException(msg);}AuthenticationInfo info = realm.getAuthenticationInfo(token);if (info == null) {String msg = "Realm [" + realm + "] was unable to find account data for the " +"submitted AuthenticationToken [" + token + "].";throw new UnknownAccountException(msg);}return info;}

   public final AuthenticationInfo getAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {AuthenticationInfo info = getCachedAuthenticationInfo(token); //从缓存中读取if (info == null) {//otherwise not cached, perform the lookup:info = doGetAuthenticationInfo(token);  //缓存中读不到，则到数据库或者ldap或者jndi等去读log.debug("Looked up AuthenticationInfo [{}] from doGetAuthenticationInfo", info);if (token != null && info != null) {cacheAuthenticationInfoIfPossible(token, info);}} else {log.debug("Using cached authentication info [{}] to perform credentials matching.", info);}if (info != null) {assertCredentialsMatch(token, info);} else {log.debug("No AuthenticationInfo found for submitted AuthenticationToken [{}].  Returning null.", token);}return info;}

    /*** Checks to see if the authenticationCache class attribute is null, and if so, attempts to acquire one from* any configured {@link #getCacheManager() cacheManager}.  If one is acquired, it is set as the class attribute.* The class attribute is then returned.** @return an available cache instance to be used for authentication caching or {@code null} if one is not available.* @since 1.2*/private Cache<Object, AuthenticationInfo> getAuthenticationCacheLazy() {if (this.authenticationCache == null) {log.trace("No authenticationCache instance set.  Checking for a cacheManager...");CacheManager cacheManager = getCacheManager();if (cacheManager != null) {String cacheName = getAuthenticationCacheName();log.debug("CacheManager [{}] configured.  Building authentication cache '{}'", cacheManager, cacheName);this.authenticationCache = cacheManager.getCache(cacheName);}}return this.authenticationCache;}

 protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {UsernamePasswordToken upToken = (UsernamePasswordToken) token;String username = upToken.getUsername();// Null username is invalidif (username == null) {throw new AccountException("Null usernames are not allowed by this realm.");}Connection conn = null;SimpleAuthenticationInfo info = null;try {conn = dataSource.getConnection();String password = null;String salt = null;switch (saltStyle) {case NO_SALT:password = getPasswordForUser(conn, username)[0];break;case CRYPT:// TODO: separate password and hash from getPasswordForUser[0]throw new ConfigurationException("Not implemented yet");//break;case COLUMN: String[] queryResults = getPasswordForUser(conn, username);password = queryResults[0];salt = queryResults[1];break;case EXTERNAL:password = getPasswordForUser(conn, username)[0];salt = getSaltForUser(username);}if (password == null) {throw new UnknownAccountException("No account found for user [" + username + "]");}info = new SimpleAuthenticationInfo(username, password.toCharArray(), getName());if (salt != null) {info.setCredentialsSalt(ByteSource.Util.bytes(salt));}} catch (SQLException e) {final String message = "There was a SQL error while authenticating user [" + username + "]";if (log.isErrorEnabled()) {log.error(message, e);}// Rethrow any SQL errors as an authentication exceptionthrow new AuthenticationException(message, e);} finally {JdbcUtils.closeConnection(conn);}return info;}

 private String[] getPasswordForUser(Connection conn, String username) throws SQLException {String[] result;boolean returningSeparatedSalt = false;switch (saltStyle) {case NO_SALT:case CRYPT:case EXTERNAL:result = new String[1];break;default:result = new String[2];returningSeparatedSalt = true;}PreparedStatement ps = null;ResultSet rs = null;try {ps = conn.prepareStatement(authenticationQuery);ps.setString(1, username);// Execute queryrs = ps.executeQuery();// Loop over results - although we are only expecting one result, since usernames should be uniqueboolean foundResult = false;while (rs.next()) {// Check to ensure only one row is processedif (foundResult) {throw new AuthenticationException("More than one user row found for user [" + username + "]. Usernames must be unique.");}result[0] = rs.getString(1);if (returningSeparatedSalt) {result[1] = rs.getString(2);}foundResult = true;}} finally {JdbcUtils.closeResultSet(rs);JdbcUtils.closeStatement(ps);}return result;}

 protected String authenticationQuery = DEFAULT_AUTHENTICATION_QUERY;protected static final String DEFAULT_AUTHENTICATION_QUERY = "select password from users where username = ?";