项目启动时shiro加载过程
1.web下的shiro启动入口（shiro1.2及之后版本）
web入口web.xml配置
<!--- shiro 1.2 --> <listener> <listener-class>org.apache.shiro.web.env.EnvironmentLoaderListener</listener-class> </listener> <context-param> <param-name>shiroEnvironmentClass</param-name> <param-value>org.apache.shiro.web.env.IniWebEnvironment</param-value><!-- 默认先从/WEB-INF/shiro.ini，如果没有找classpath:shiro.ini --> </context-param> <context-param> <param-name>shiroConfigLocations</param-name> <param-value>classpath:shiro.ini</param-value> </context-param> <filter> <filter-name>shiroFilter</filter-name> <filter-class>org.apache.shiro.web.servlet.ShiroFilter</filter-class> </filter> <filter-mapping> <filter-name>shiroFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
EnvironmentLoaderListener是一个ServletContextListener，会在容器启动和销毁的时候执行对应方法。实际上具体的方法在父类EnvironmentLoader中实现
public class EnvironmentLoaderListener extends EnvironmentLoader implements ServletContextListener { //servlet容器启动的时候调用 public void contextInitialized(ServletContextEvent sce) { initEnvironment(sce.getServletContext()); } //servlet容器销毁的时候调用 public void contextDestroyed(ServletContextEvent sce) { destroyEnvironment(sce.getServletContext()); }
}
下面详细看一下EnvironmentLoader中启动初始化方法initEnvironment（源码EnvironmentLoader类119行）
public WebEnvironment initEnvironment(ServletContext servletContext) throws IllegalStateException {
//防止已经被初始化过了，这里做个校验 if (servletContext.getAttribute(ENVIRONMENT_ATTRIBUTE_KEY) != null) { String msg = "There is already a Shiro environment associated with the current ServletContext. " + "Check if you have multiple EnvironmentLoader* definitions in your web.xml!"; throw new IllegalStateException(msg); } servletContext.log("Initializing Shiro environment"); log.info("Starting Shiro environment initialization."); long startTime = System.currentTimeMillis(); try {
//重点是这，创建WebEnvironment WebEnvironment environment = createEnvironment(servletContext); servletContext.setAttribute(ENVIRONMENT_ATTRIBUTE_KEY, environment); log.debug("Published WebEnvironment as ServletContext attribute with name [{}]", ENVIRONMENT_ATTRIBUTE_KEY); if (log.isInfoEnabled()) { long elapsed = System.currentTimeMillis() - startTime; log.info("Shiro environment initialized in {} ms.", elapsed); } return environment; } catch (RuntimeException ex) { log.error("Shiro environment initialization failed", ex); servletContext.setAttribute(ENVIRONMENT_ATTRIBUTE_KEY, ex); throw ex; } catch (Error err) { log.error("Shiro environment initialization failed", err); servletContext.setAttribute(ENVIRONMENT_ATTRIBUTE_KEY, err); throw err; } }
下面看一下创建WebEnvironment过程（源码EnvironmentLoader类，193行）
protected WebEnvironment createEnvironment(ServletContext sc) {
//加载IniWebEnvironment Class<?> clazz = determineWebEnvironmentClass(sc); if (!MutableWebEnvironment.class.isAssignableFrom(clazz)) { throw new ConfigurationException("Custom WebEnvironment class [" + clazz.getName() + "] is not of required type [" + WebEnvironment.class.getName() + "]"); }
//获取shiro配置路径 String configLocations = sc.getInitParameter(CONFIG_LOCATIONS_PARAM); boolean configSpecified = StringUtils.hasText(configLocations); if (configSpecified && !(ResourceConfigurable.class.isAssignableFrom(clazz))) { String msg = "WebEnvironment class [" + clazz.getName() + "] does not implement the " + ResourceConfigurable.class.getName() + "interface. This is required to accept any " + "configured " + CONFIG_LOCATIONS_PARAM + "value(s)."; throw new ConfigurationException(msg); } MutableWebEnvironment environment = (MutableWebEnvironment) ClassUtils.newInstance(clazz); environment.setServletContext(sc); if (configSpecified && (environment instanceof ResourceConfigurable)) { ((ResourceConfigurable) environment).setConfigLocations(configLocations); } customizeEnvironment(environment);
//重点是初始化过程 LifecycleUtils.init(environment); return environment; }
上面代码加载IniWebEnvironment的就是web.xml中shiroEnvironmentClass配置的org.apache.shiro.web.env.IniWebEnvironment，加载过程如下（源码EnvironmentLoader类，165行），ENVIRONMENT_CLASS_PARAM=shiroEnvironmentClass，CONFIG_LOCATIONS_PARAM=shiroConfigLocations（就是web.xml配置的两个全局参数）
protected Class<?> determineWebEnvironmentClass(ServletContext servletContext) { String className = servletContext.getInitParameter(ENVIRONMENT_CLASS_PARAM); if (className != null) { try { return ClassUtils.forName(className); } catch (UnknownClassException ex) { throw new ConfigurationException( "Failed to load custom WebEnvironment class [" + className + "]", ex); } } else { return IniWebEnvironment.class; } }
下面分析初始化过程LifecycleUtils.init(environment)，最终会调用IniWebEnvironment的init（）方法（源代码IniWebEnvironment类，62行）public void init() { //这里暂时还没有配置文件，需要从前面加载的configLocations路径中加载
Ini ini = getIni(); String[] configLocations = getConfigLocations(); if (log.isWarnEnabled() && !CollectionUtils.isEmpty(ini) && configLocations != null && configLocations.length > 0) { log.warn("Explicit INI instance has been provided, but configuration locations have also been " + "specified. The {} implementation does not currently support multiple Ini config, but this may " + "be supported in the future. Only the INI instance will be used for configuration.", IniWebEnvironment.class.getName()); } if (CollectionUtils.isEmpty(ini)) { log.debug("Checking any specified config locations.");
//从配置路径下加载shiro配置 ini = getSpecifiedIni(configLocations); } if (CollectionUtils.isEmpty(ini)) { log.debug("No INI instance or config locations specified. Trying default config locations."); ini = getDefaultIni(); } if (CollectionUtils.isEmpty(ini)) { String msg = "Shiro INI configuration was either not found or discovered to be empty/unconfigured."; throw new ConfigurationException(msg); } setIni(ini);
//重点又来了，shiro需要的类是从这里开始加载的 configure(); }
下面分析configure（）方法，（源代码IniWebEnvironment类，95行）
protected void configure() { this.objects.clear(); //1创建securityManager，这里创建的是DefaultWebSecurityManager实例 WebSecurityManager securityManager = createWebSecurityManager(); setWebSecurityManager(securityManager);
//2从配置里（这里是.ini配置文件）生成拦截器链 FilterChainResolver resolver = createFilterChainResolver(); if (resolver != null) { setFilterChainResolver(resolver); } }
构造securityManager过程和生成url拦截器链列表都很简单，这里就不展开了，感兴趣的同学可以自己debug一下。源码debug入口参考开涛大神跟我学shiro第七章实例。
简单的总结一下原生的java web项目启动时配置shiro的过程：
（1）通过EnvironmentLoaderListener监听sevlet容器启动，触发shiro初始化操作。初始化动作实际上交给其父类EnvironmentLoader实现。
（2）EnvironmentLoader主要动作是创建WebEnvironment的实现类IniWebEnvironment。
（3）IniWebEnvironment该类的作用是加载shiro初始化配置文件，然后配置SecurityManager和FilterChainResolver
（4）启动完成后，配置shiroFilter，所有路径的请求都会走该拦截器。
补充一下shiroFilter初始化
public class ShiroFilter extends AbstractShiroFilter { /** * Configures this instance based on the existing {@link org.apache.shiro.web.env.WebEnvironment} instance * available to the currently accessible {@link #getServletContext() servletContext}. * * @see org.apache.shiro.web.env.EnvironmentLoaderListener * @since 1.2 */ @Override public void init() throws Exception {
//（1）获取webEnvironment实例 WebEnvironment env = WebUtils.getRequiredWebEnvironment(getServletContext()); //（2）绑定securityManager setSecurityManager(env.getWebSecurityManager()); //（3）绑定filterChainResolver FilterChainResolver resolver = env.getFilterChainResolver(); if (resolver != null) { setFilterChainResolver(resolver); } } }
shiroFilter拦截器的实现主要在父类AbstractShiroFilter中实现，关于shiro拦截器的实现计划另有篇幅讨论，这里不深入研究，主要看一下初始化过程。
shiroFilter初始化第一步是获取WebEnvironment实例，也就是我们前面分析的IniWebEnvironment实例，该实例有两个属性SecurityManager和FilterChainResolver，shiroFilter给自己set。
然而现在项目基本不会这么使用了，了解基础的使用是为了更好的掌握shiro原理，这样结合框加就不会知其然不知其所以然，下面我们一起分析spring boot下的shiro启动入口。
2.spring boot下的shiro启动入口
maven 依赖
<dependency> <groupId>org.apache.shiro</groupId> <artifactId>shiro-spring</artifactId> </dependency>
本次实例使用java方式配置shiro，完整的配置代码如下。cacheManager和sessionDao可自行实现，例如基于redis
@Configuration public class ShiroConfig { @Value("${shiro.session.expire.time}") private int globalSessionTimeOut; @Value("${shiro.cache.key}") private String shiroCacheKey; @Value("${shiro.login.url}") private String shiroLoginUrl; @Value("${shiro.auth.switch}") private boolean authSwitch; @Bean(name = "shiroFilter") public ShiroFilterFactoryBean shiroFilter(SecurityManager securityManager) { ShiroFilterFactoryBean shiroFilterFactoryBean = new ShiroFilterFactoryBean(); shiroFilterFactoryBean.setSecurityManager(securityManager); // 没有登陆的用户只能访问登陆页面 shiroFilterFactoryBean.setLoginUrl(shiroLoginUrl); //配置URL权限控制 Map<String, String> filterChainDefinitionMap = new LinkedHashMap<>(); if (authSwitch) { filterChainDefinitionMap.put(API_BASE + "/auth/login", "anon"); filterChainDefinitionMap.put(API_BASE + "/auth/logout", "anon"); filterChainDefinitionMap.put(API_BASE + "/auth/noauth", "anon"); filterChainDefinitionMap.put(API_BASE + "/auth/check", "anon"); filterChainDefinitionMap.put(API_BASE + "/auth/kickout", "anon"); filterChainDefinitionMap.put(API_ANON_BASE + "/**", "anon"); filterChainDefinitionMap.put("/**", "authc"); } shiroFilterFactoryBean.setFilterChainDefinitionMap(filterChainDefinitionMap); return shiroFilterFactoryBean; } @Bean public FilterRegistrationBean filterRegistrationBean() { FilterRegistrationBean filterRegistration = new FilterRegistrationBean(); filterRegistration.setFilter(new DelegatingFilterProxy("shiroFilter")); filterRegistration.addInitParameter("targetFilterLifecycle", "true"); filterRegistration.setEnabled(true); filterRegistration.addUrlPatterns("/*"); return filterRegistration; } @Bean public Realm realm(CacheManager cacheManager, CredentialsMatcher credentialsMatcher) { MyRealm myRealm = new MyRealm(); myRealm.setCredentialsMatcher(credentialsMatcher); myRealm.setCacheManager(cacheManager); return myRealm; } @Bean public CredentialsMatcher credentialsMatcher() { HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(); matcher.setHashAlgorithmName(PcdnConst.HASH_ALGORITHM); matcher.setHashIterations(PcdnConst.HASH_ITERATIONS); return matcher; } @Bean public SecurityManager securityManager(Realm realm, CacheManager cacheManager, SessionManager sessionManager) { DefaultWebSecurityManager securityManager = new DefaultWebSecurityManager(); // 设置realm. securityManager.setRealm(realm); // 设置缓存 securityManager.setCacheManager(cacheManager); // 配置session管理 securityManager.setSessionManager(sessionManager); return securityManager; } /** * Session Manager * 使用的是shiro-redis开源插件 */ @Bean public SessionManager sessionManager(SessionListener sessionListener, SessionDAO sessionDAO, CacheManager cacheManager, Cookie sessionIdCookie) { DefaultWebSessionManager sessionManager = new DefaultWebSessionManager(); sessionManager.setCacheManager(cacheManager); sessionManager.setSessionDAO(sessionDAO); sessionManager.setGlobalSessionTimeout(globalSessionTimeOut * 1000L); sessionManager.setSessionIdCookie(sessionIdCookie); sessionManager.setSessionListeners(new ArrayList<SessionListener>() {{ add(sessionListener); }}); return sessionManager; } @Bean("sessionIdCookie") public Cookie simpleCookie() { SimpleCookie cookie = new SimpleCookie(ShiroHttpSession.DEFAULT_SESSION_ID_NAME); //sessionIdCookie过期时间这里设置和会话有效期一样，不设置的话默认为-1，cookie关闭浏览器过期 cookie.setMaxAge(globalSessionTimeOut); return cookie; }/** * Shiro生命周期处理器，注意这里使用static修饰，@Value值不能初始化（原因可自行研究） */ @Bean public static LifecycleBeanPostProcessor getLifecycleBeanPostProcessor() { return new LifecycleBeanPostProcessor(); } @Bean public DefaultAdvisorAutoProxyCreator getDefaultAdvisorAutoProxyCreator() { DefaultAdvisorAutoProxyCreator daap = new DefaultAdvisorAutoProxyCreator(); daap.setProxyTargetClass(true); return daap; } @Bean public AuthorizationAttributeSourceAdvisor getAuthorizationAttributeSourceAdvisor(org.apache.shiro.mgt.SecurityManager securityManager) { AuthorizationAttributeSourceAdvisor aasa = new AuthorizationAttributeSourceAdvisor(); aasa.setSecurityManager(securityManager); return aasa; } }
加载配置的入口类ShiroFilterFactoryBean，从名字可以猜测这是一个spring的工厂类，
类签名：public class ShiroFilterFactoryBean implements FactoryBean, BeanPostProcessor
spring在实例化的时候会调用其getObject实现，源代码ShiroFilterFactoryBean ，第341行
public Object getObject() throws Exception { if (instance == null) { instance = createInstance(); } return instance; }
createInstance会创建一个AbstractShiroFilter的实现类SpringShiroFilter的实例，源代码ShiroFilterFactoryBean ，第422行
protected AbstractShiroFilter createInstance() throws Exception { log.debug("Creating Shiro Filter instance.");
//（1）获取前面shiroConfig中配置的securityManager SecurityManager securityManager = getSecurityManager(); if (securityManager == null) { String msg = "SecurityManager property must be set."; throw new BeanInitializationException(msg); } if (!(securityManager instanceof WebSecurityManager)) { String msg = "The security manager does not implement the WebSecurityManager interface."; throw new BeanInitializationException(msg); }
//（2）添加shiro的11个默认filter和自定义的filter FilterChainManager manager = createFilterChainManager(); //Expose the constructed FilterChainManager by first wrapping it in a // FilterChainResolver implementation. The AbstractShiroFilter implementations // do not know about FilterChainManagers - only resolvers: PathMatchingFilterChainResolver chainResolver = new PathMatchingFilterChainResolver(); chainResolver.setFilterChainManager(manager); //Now create a concrete ShiroFilter instance and apply the acquired SecurityManager and built //FilterChainResolver. It doesn't matter that the instance is an anonymous inner class //here - we're just using it because it is a concrete AbstractShiroFilter instance that accepts //injection of the SecurityManager and FilterChainResolver:
//（3）创建一个springShiroFilter实例 return new SpringShiroFilter((WebSecurityManager) securityManager, chainResolver); }
上面代码的（1）（2）步骤是不是有点眼熟，和原生java web加载shiro配置的功能类似。最后（3）会生成springShiroFilter实例托管给spring容器。
为什么要将ShiroFilter托管给spring容器？
很好理解，我们是基于spring配置来接入shiro的，理所应当的可以使用spring的ioc特性来管理shiro相关bean。配置中需要使用spring容器中的实例时可以直接注入。
所以
这里shiroFile不能使用前面原生的java web的web.xml中的org.apache.shiro.web.servlet.ShiroFilter，因为init（）方法没法初始化。相关配置需要从spring容器中获取，所以使用了DelegatingFilterProxy来代理shiroFilter。
DelegatingFilterProxy是spring对于servlet filter的通用代理类，指定targetBeanName后，可以从容器中获取filter实例。
