规范中引入了新的 Web 组件技术——过滤器 （Filter），使上述难题迎刃而解。 大纲 过滤器概述 Java EE 过滤器 API Java EE 过滤器编程和配置 过滤器的主要任务 本节习题 过滤器的基本概念 过滤器，对某种数据流动进行过滤处理的对象。在 Java EE Web 应用中，这种数据流动就是 HTTP 请求数据流和响应数据流。 ▶ Filter 是对 HTTP 请求和响应的头（Header）和体（Body） 请求和响应的头（Header）和体（Body） 进行特殊操作的 Web 组件。 ▶ Filter 本身不生成 Web 响应，只对 Web 的请求和响应做过 滤处理。这些操作都是在 Web 组件和浏览器毫不知情的情 况下进行的。 大纲 过滤器概述 Java EE 过滤器 API Java EE 过滤器编程和配置 过滤器的主要任务 本节习题 过滤器的基本功能 过滤器采用 AOP（Aspect Oriented Programming）编程思想， 过滤器的主要任务 本节习题 大纲 过滤器概述 Java EE 过滤器 API Java EE 过滤器编程和配置 过滤器的主要任务 本节习题 javax.servlet.Filter 接口 所有过滤器必须实现 javax.servlet.Filter 接口。 public void init(FilterConfig filterConfig) throws ServletException 初始化方法，在

ServletContext，默认使用 IniWebEnvironment 实现。 <filter> <filter-name>iniShiroFilterfilter-name> <filter-class>org.apache.shiro.web.servlet.IniShiroFilterfilter-class> filter> <filter-mapping> <filter-name>iniShiroFilterfilter-name> /* filter-mapping> config 集成 DelegatingFilterProxy 作用是自动到 spring 容器查找名字为 shiroFilter（filter-name）的 bean 并把所有 Filter 的操作委托给它。然后将 ShiroFilter 配置到 spring 容器即可： 最后不要忘了使用 org.springframework.web

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_proxy_scgi: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ssl: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path

present in all the necessary directory contexts. mod_filter: FilterProvider syntax has changed and now uses a boolean expression to determine if a filter is applied. mod_include: The #if expr element now mod_charset_lite: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ext_filter: The DebugLevel option has been removed in favour of per-module LogLevel configuration. mod_ssl: module not included in the server configuration - AddOutputFilterByType has moved from the core to mod_filter, which must be loaded. Errors serving requests: configuration error: couldn't check user: /path