spring集成shiro登陆流程（上）

public final void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
            throws ServletException, IOException {
　　　　//当前过滤器的名字
        String alreadyFilteredAttributeName = getAlreadyFilteredAttributeName();
　　　　　//如果该过滤器执行过，那么将不执行同一个名字的过滤器 直接执行过滤链中的下一个过滤器
        if ( request.getAttribute(alreadyFilteredAttributeName) != null ) {
            filterChain.doFilter(request, response);

        } else if (!isEnabled(request, response) || shouldNotFilter(request) ) {
　　　　　　　　//如果当前过滤器设置了enabled属性为false，则不执行，直接执行过滤链中的下一个过滤器
            filterChain.doFilter(request, response);
        } else {
            //标志当前过滤器已经执行过
            request.setAttribute(alreadyFilteredAttributeName, Boolean.TRUE);
            try {
　　　　　　　　　　//1、 核心方法
                doFilterInternal(request, response, filterChain);
            } finally {
                //过滤链执行完毕后，清空request中的过滤链执行记录
                request.removeAttribute(alreadyFilteredAttributeName);
            }
        }
    }

protected void doFilterInternal(ServletRequest servletRequest, ServletResponse servletResponse, final FilterChain chain)
        throws ServletException, IOException {
            
     //封装容器的request和response为shiro自己的 其中在request中标识了当前不为servlet容器的session （在创建session时会用到servlet容器调用getSession()时 ）
    final ServletRequest request = prepareServletRequest(servletRequest, servletResponse, chain);
    final ServletResponse response = prepareServletResponse(request, servletResponse, chain);
    //2、 创建subject（可以看出每次请求都会创建一个Subject对象）
    final Subject subject = createSubject(request, response);

    //执行过滤链
    subject.execute(new Callable() {
        public Object call() throws Exception {
            updateSessionLastAccessTime(request, response);  //修改session的最后活动时间
            executeChain(request, response, chain);  //执行过滤链
            return null;
        }
    });
}
//创建subject对象
protected WebSubject createSubject(ServletRequest request, ServletResponse response) {
    return new WebSubject.Builder(getSecurityManager(), request, response).buildWebSubject();
}
//7、执行过滤链
protected void executeChain(ServletRequest request, ServletResponse response, FilterChain origChain)
        throws IOException, ServletException {
    //获取当前请求对应的过滤链
    FilterChain chain = getExecutionChain(request, response, origChain);
    chain.doFilter(request, response);
}

//3、
public Builder(SecurityManager securityManager, ServletRequest request, ServletResponse response) {
    //每次都创建subject上下文(subjectContext),  并设置securityManager对象
    super(securityManager);
    //将request和response添加到subject上下文（subjectContext）， 即上面创建的对象
    setRequest(request);
    setResponse(response);
}
//4、创建
public WebSubject buildWebSubject() {
    Subject subject = super.buildSubject();
    return (WebSubject) subject;
}

//5、调用DefaultSecurityManager的createSubject方法

public Subject buildSubject() {
　　return this.securityManager.createSubject(this.subjectContext);
}

// 6
public Subject createSubject(SubjectContext subjectContext) {
    //web的subjectContext时，会重新创建一个新的，其他的（ini等），只是copy
    SubjectContext context = copy(subjectContext);

    //验证是否subject上下文中有securityMangary对象，如果没有创建一个
    context = ensureSecurityManager(context);
    
    //将session放入subjectContext 该session会从cookie或者rul上带的JSESSIONID(默认) 注意：第一次访问项目来到这儿没有session
    context = resolveSession(context);

    //校验用户登陆信息, 并放入context, 如果subject,session,和授权认证AuthenticationInfo中都没有，将会从rememberMeManager（cookie）中获取
　　　//注意：第一次访问项目来到这儿没有这些信息
    context = resolvePrincipals(context);
    
    //创建一个WebDelegatingSubject对象
    Subject subject = doCreateSubject(context);

    //保存当前认证的用户信息（一般是用户名）在session里，并标记当前用户已经被认证过  为了下次remember使用
    save(subject);

    return subject;
}

// 从context中获取session
protected SubjectContext resolveSession(SubjectContext context) {
    Session session = resolveContextSession(context);
    if (session != null) {
        context.setSession(session);
    }
    return context;
}
protected Session resolveContextSession(SubjectContext context) throws InvalidSessionException {
    //调用的下面子类DefaultWebSecurityManager的方法
    SessionKey key = getSessionKey(context);
    if (key != null) {
        //调用 SessionsSecurityManager#getSession
        return getSession(key);
    }
    return null;
}

//登陆
public Subject login(Subject subject, AuthenticationToken token) throws AuthenticationException {
    AuthenticationInfo info;
    try {
        info = authenticate(token);
    } catch (AuthenticationException ae) {
        onFailedLogin(token, ae, subject);
    }
    Subject loggedIn = createSubject(token, info, subject);
    //登陆成功后 根据配置的"记住我" 保存认证信息
    onSuccessfulLogin(token, info, loggedIn);
    return loggedIn;
}

protected void onSuccessfulLogin(AuthenticationToken token, AuthenticationInfo info, Subject subject) {
    rememberMeSuccessfulLogin(token, info, subject);
}
protected void rememberMeSuccessfulLogin(AuthenticationToken token, AuthenticationInfo info, Subject subject) {
    //获取 rememberMeManager管理器
    RememberMeManager rmm = getRememberMeManager();
    rmm.onSuccessfulLogin(subject, token, info);
}

//创建sessionKey
@Override
protected SessionKey getSessionKey(SubjectContext context) {
    //从context中获取sessonId和request，response
    if (WebUtils.isWeb(context)) {
        Serializable sessionId = context.getSessionId();
        ServletRequest request = WebUtils.getRequest(context);
        ServletResponse response = WebUtils.getResponse(context);
        return new WebSessionKey(sessionId, request, response);
    } else {
        ...
    }
}
// 第一次调用时 getSession方法最后会调用到这儿来 返回null
protected Session retrieveSession(SessionKey sessionKey) throws UnknownSessionException {
    Serializable sessionId = getSessionId(sessionKey);
    if (sessionId == null) {
        return null;
    }
    Session s = retrieveSessionFromDataSource(sessionId);
    if (s == null) {
        //session ID was provided, meaning one is expected to be found, but we couldn‘t find one:
        String msg = "Could not find session with ID [" + sessionId + "]";
        throw new UnknownSessionException(msg);
    }
    return s;
}

public void doFilterInternal(ServletRequest request, ServletResponse response, FilterChain chain)
            throws ServletException, IOException {

        Exception exception = null;
        try {
　　　　　　　//8、执行前置方法
            boolean continueChain = preHandle(request, response);
　　　　　　　if (continueChain) {
                executeChain(request, response, chain);
            }

            postHandle(request, response);
            if (log.isTraceEnabled()) {
                log.trace("Successfully invoked postHandle method");
            }

        } catch (Exception e) {
            exception = e;
        } finally {
            cleanup(request, response, exception);
        }
    }

public boolean onPreHandle(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
    //9、是登陆的rul或者已经认证过 否则重定向到登陆页面
    return isAccessAllowed(request, response, mappedValue) || onAccessDenied(request, response, mappedValue);
}

//10、判断是否认证过
protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
　　//判断当前请求的路径是否为当前过滤器配置的登陆路径(登陆不需要任何权限，返回true)
    if (isLoginRequest(request, response)) {
        return true;
    } else {
　　　　//判断是否已经认证过
        Subject subject = getSubject(request, response);
        return subject.getPrincipal() != null;
    }
}
//11、返回false
protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
　　//重定向到登陆rul
    saveRequestAndRedirectToLogin(request, response);
    return false;
}
//12、
protected void saveRequestAndRedirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
    //调用webUtils的方法，将当前请求失败的的信息保存起来（便于下次认证成功后直接重定向到该路径）
    saveRequest(request);
    //重定向的时候会生成session（shrio的）
    redirectToLogin(request, response);
}

//保存
public static void saveRequest(ServletRequest request) {
    Subject subject = SecurityUtils.getSubject();
    //13、这里会创建一个 StoppingAwareProxiedSession   AbstractNativeSessionManager#start是创建simpleSession并调用session监听器
　　//会将sessinID存在cookie中和sessionDao中（默认时ehcache缓存，可以自己实现redis等）（在DefaultSessionManager#create(Session session)方法中）
    Session session = subject.getSession();
    HttpServletRequest httpRequest = toHttp(request);
    //将当前目标路径的请求信息保存起来
    SavedRequest savedRequest = new SavedRequest(httpRequest);
    //存到session中，跳到登陆页面后登陆成功后会重定向到此次失败的路径
    session.setAttribute(SAVED_REQUEST_KEY, savedRequest);
}
//重定向到savedRequet保存的路径 如果是直接访问的登陆url，则直接重定向到当前过滤器配置的登陆成功url
//成功后的重定向可是不生成session的
public static void redirectToSavedRequest(ServletRequest request, ServletResponse response, String fallbackUrl)
        throws IOException {
    String successUrl = null;
    boolean contextRelative = true;
    //从session中获取，并清空上一次失败保存的信息
    SavedRequest savedRequest = WebUtils.getAndClearSavedRequest(request);
    //上一次请求失败的保存的对象  而且是get请求（这里一般是直接浏览器输入的url） 如果是post请求过来的（一般是表单），直接返回目标路径
    if (savedRequest != null && savedRequest.getMethod().equalsIgnoreCase(AccessControlFilter.GET_METHOD)) {
        successUrl = savedRequest.getRequestUrl();
        contextRelative = false;
    }
　　//第一次请求时，successUrl为null, 登陆成功后，有值（上一次失败的url）
    if (successUrl == null) {
        successUrl = fallbackUrl;
    }
　　//15、发出重定向
    WebUtils.issueRedirect(request, response, successUrl, null, contextRelative);
}

public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative) throws IOException {
    issueRedirect(request, response, url, queryParams, contextRelative, true);
}
// 会把sessionID写在rul上， 下面的内容就不带大家看了
public static void issueRedirect(ServletRequest request, ServletResponse response, String url, Map queryParams, boolean contextRelative, boolean http10Compatible) throws IOException {
    RedirectView view = new RedirectView(url, contextRelative, http10Compatible);
    view.renderMergedOutputModel(queryParams, toHttp(request), toHttp(response));
}

// SavedRequest的构造方法
public SavedRequest(HttpServletRequest request) {
　　//当前请求的方式（get|post...）
    this.method = request.getMethod();
　　//当前请求的参数
    this.queryString = request.getQueryString();
　　//当前请求失败的路径
    this.requestURI = request.getRequestURI();
}

public final void renderMergedOutputModel(
            Map model, HttpServletRequest request, HttpServletResponse response) throws IOException {

        // Prepare name URL.
        StringBuilder targetUrl = new StringBuilder();
        if (this.contextRelative && getUrl().startsWith("/")) {
            targetUrl.append(request.getContextPath());
        }
        targetUrl.append(getUrl());
　　　　　//拼接请求参数
        appendQueryProperties(targetUrl, model, this.encodingScheme);
        sendRedirect(request, response, targetUrl.toString(), this.http10Compatible);
    }

//14、创建session时会调用
public Session start(SessionContext context) {
    //创建simpleSession
    Session session = createSession(context);
    //重置session时间
    applyGlobalSessionTimeout(session);
　　//会将sessionID存到cookie
    onStart(session, context);
    //调用session的Listner
    notifyStart(session);
    //Don‘t expose the EIS-tier Session object to the client-tier:
    return createExposedSession(session, context);
}

// 这里需要该过滤器的 登陆url 和登陆所在的界面的url一样
protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
    //条件： 配置的该过滤器的登陆路径和请求路径相同
    if (isLoginRequest(request, response)) {
        //1、HttpServletRequest  2、post请求
        if (isLoginSubmission(request, response)) {
            return executeLogin(request, response);
        } else {
            //登陆页面的url 请求方式为get
            return true;
        }
    } else {
        //如果一个请求路径配置的authc过滤器，然后没有登陆直接调用，会走到这里
        //重定向到登陆页面  会创建一个StoppingAwareProxiedSession类型的session 并把sessionId放在登陆页面的url上
        saveRequestAndRedirectToLogin(request, response);
        return false;
    }
}

protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
    //调用 new UsernamePasswordToken(username, password, rememberMe, host);
    AuthenticationToken token = createToken(request, response);
    try {
        Subject subject = getSubject(request, response);
        subject.login(token);
        return onLoginSuccess(token, subject, request, response);
    } catch (AuthenticationException e) {
        return onLoginFailure(token, e, request, response);
    }
}
//登陆成功后 重定向到上一次重定向过来的路径或者当前过滤器的登陆路径
//可以重写该方法登陆后直接跳到当前过滤器配置的url  而不是上一次失败的url
protected boolean onLoginSuccess(AuthenticationToken token, Subject subject,
                                 ServletRequest request, ServletResponse response) throws Exception {
    //调用父类AuthenticationFilter的issueSuccessRedirect方法
    issueSuccessRedirect(request, response);
    //重定向后，阻止过滤连调用
    return false;
}

protected void issueSuccessRedirect(ServletRequest request, ServletResponse response) throws Exception {
    //当前过滤器配置的登陆url
    WebUtils.redirectToSavedRequest(request, response, getSuccessUrl());
}

public void login(AuthenticationToken token) throws AuthenticationException {
    clearRunAsIdentitiesInternal();
    //委托给securiManager登陆
    Subject subject = securityManager.login(this, token);
    PrincipalCollection principals;
    String host = null;
    if (subject instanceof DelegatingSubject) {
        DelegatingSubject delegating = (DelegatingSubject) subject;
        //认证信息
        principals = delegating.principals;
        host = delegating.host;
    } else {
        principals = subject.getPrincipals();
    }
    this.principals = principals;
    //标记已经登陆过
    this.authenticated = true;
    if (token instanceof HostAuthenticationToken) {
        host = ((HostAuthenticationToken) token).getHost();
    }
    if (host != null) {
        this.host = host;
    }
    //获取登陆时的session
    Session session = subject.getSession(false);
    if (session != null) {
        //执行new StoppingAwareProxiedSession(session, this);  登陆后的session封装成StoppingAwareProxiedSession代理对象
        this.session = decorate(session);
    } else {
        this.session = null;
    }
}

public void onSuccessfulLogin(Subject subject, AuthenticationToken token, AuthenticationInfo info) {
    //清空之前的认证信息
    forgetIdentity(subject);

    //如果是rememberMe类型的token
    if (isRememberMe(token)) {
        //记录
        rememberIdentity(subject, token, info);
    }
}
public void rememberIdentity(Subject subject, AuthenticationToken token, AuthenticationInfo authcInfo) {
    //从认证后的信息中获取
    PrincipalCollection principals = getIdentityToRemember(subject, authcInfo);
    rememberIdentity(subject, principals);
}
// 加密处理
protected void rememberIdentity(Subject subject, PrincipalCollection accountPrincipals) {
    byte[] bytes = convertPrincipalsToBytes(accountPrincipals);
    rememberSerializedIdentity(subject, bytes);
}
//使用CipherService类进行处理
protected byte[] convertPrincipalsToBytes(PrincipalCollection principals) {
    byte[] bytes = serialize(principals);
    if (getCipherService() != null) {
        bytes = encrypt(bytes);
    }
    return bytes;
}
// 返回加密后的认证信息
protected byte[] encrypt(byte[] serialized) {
    byte[] value = serialized;
    CipherService cipherService = getCipherService();
    if (cipherService != null) {
        // getEncryptionCipherKey()  获取的是rememberMe cookie加密和解密的密钥
        ByteSource byteSource = cipherService.encrypt(serialized, getEncryptionCipherKey());
        value = byteSource.getBytes();
    }
    return value;
}
//加密
protected byte[] encrypt(byte[] serialized) {
    byte[] value = serialized;
    CipherService cipherService = getCipherService();
    if (cipherService != null) {
        ByteSource byteSource = cipherService.encrypt(serialized, getEncryptionCipherKey());
        value = byteSource.getBytes();
    }
    return value;
}

protected void rememberSerializedIdentity(Subject subject, byte[] serialized) {
    HttpServletRequest request = WebUtils.getHttpRequest(subject);
    HttpServletResponse response = WebUtils.getHttpResponse(subject);

    //base 64 encode it and store as a cookie:
    String base64 = Base64.encodeToString(serialized);
    //rememberMe的cookie模板  key为自定义的名字  我这儿是rememberMe
    Cookie template = getCookie();
    Cookie cookie = new SimpleCookie(template);
    cookie.setValue(base64);
    cookie.saveTo(request, response);
}

<bean id="rememberMeCookie" class="org.apache.shiro.web.servlet.SimpleCookie">
    <constructor-arg value="rememberMe"/>
    <property name="httpOnly" value="true"/>
    <property name="maxAge" value="2592000"/><!-- 30天 -->
</bean>

<!-- rememberMe管理器 -->
<bean id="rememberMeManager" class="org.apache.shiro.web.mgt.CookieRememberMeManager">
    <!-- rememberMe cookie加密和解密的密钥 建议每个项目都不一样 默认AES算法 密钥长度（128 256 512 位）-->
    <property name="cipherKey"
              value="#{T(org.apache.shiro.codec.Base64).decode(‘4AvVhmFLUs0KTA3Kprsdag==‘)}"/>
    <property name="cookie" ref="rememberMeCookie"/>
</bean>