acegi的登陆过程

先来无事看看acegi的登陆过滤器 写下来当作备忘吧
主要的类是AuthenticationProcessingFilter 继承了AbstractProcessingFilter 这要的逻辑都在后面这个类中
让我们看看核心代码吧
[code] public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
ServletException {
if (!(request instanceof HttpServletRequest)) {
throw new ServletException("Can only process HttpServletRequest");
}

if (!(response instanceof HttpServletResponse)) {
throw new ServletException("Can only process HttpServletResponse");
}

HttpServletRequest httpRequest = (HttpServletRequest) request;
HttpServletResponse httpResponse = (HttpServletResponse) response;

if (requiresAuthentication(httpRequest, httpResponse)) {
if (logger.isDebugEnabled()) {
logger.debug("Request is to process authentication");
}

Authentication authResult;
//下面才是重点 上面都是些基本检查
try {
onPreAuthentication(httpRequest, httpResponse);
authResult = attemptAuthentication(httpRequest);//这个方法就是去登陆了 就是调用dao检查用户名密码 登陆不成功将抛出异常
}
catch (AuthenticationException failed) {
// Authentication failed
unsuccessfulAuthentication(httpRequest, httpResponse, failed);

return;
}

// Authentication success
if (continueChainBeforeSuccessfulAuthentication) {
chain.doFilter(request, response);
}

successfulAuthentication(httpRequest, httpResponse, authResult);

return;
}

chain.doFilter(request, response);
}[/code]

看一些登陆成功后 做些什么
[code] protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response,
Authentication authResult) throws IOException {
if (logger.isDebugEnabled()) {
logger.debug("Authentication success: " + authResult.toString());
}

//把用户信息保存到SecurityContextHolder中1980
SecurityContextHolder.getContext().setAuthentication(authResult);

if (logger.isDebugEnabled()) {
logger.debug("Updated SecurityContextHolder to contain the following Authentication: '" + authResult + "'");
}
//转到目标页面 即登陆成功页面
String targetUrl = determineTargetUrl(request);

if (logger.isDebugEnabled()) {
logger.debug("Redirecting to target URL from HTTP Session (or default): " + targetUrl);
}

onSuccessfulAuthentication(request, response, authResult);

rememberMeServices.loginSuccess(request, response, authResult);

// Fire event
if (this.eventPublisher != null) {
eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(authResult, this.getClass()));
}

sendRedirect(request, response, targetUrl);
}[/code]