Servlet3.0动态配置过滤器、监听器、Servlet

柔情只为你懂 2021-09-02 05:18 430阅读 0赞

Servlet 3.0 作为 Java EE 6 规范体系中一员，随着 Java EE 6 规范一起发布。该版本在前一版本（Servlet 2.5）的基础上提供了若干新特性用于简化 Web 应用的开发和部署。然后本博客就其中的一个特征，动态配置过滤器、监听器、Servlet，进行介绍

<dependency>
    	<groupId>javax.servlet</groupId>
    	<artifactId>javax.servlet-api</artifactId>
    	<scope>provided</scope>
    	<version>3.1.0</version>
    </dependency>

实现AbstractAnnotationConfigDispatcherServletInitializer类：

package com.extra.login.core.servlet;
    
    import com.extra.login.cas.client.filter.authentication.AuthenticationFilter;
    import com.extra.login.cas.client.filter.session.SingleSignOutFilter;
    import com.extra.login.cas.client.util.AssertionThreadLocalFilter;
    import com.extra.login.cas.client.util.CasParamKeyEnum;
    import com.extra.login.cas.client.util.CasPropertiesLoader;
    import com.extra.login.cas.client.util.HttpServletRequestWrapperFilter;
    import org.jasig.cas.client.session.SingleSignOutHttpSessionListener;
    import org.jasig.cas.client.validation.Cas30ProxyReceivingTicketValidationFilter;
    import org.springframework.stereotype.Component;
    import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
    
    import javax.servlet.*;
    import java.util.EnumSet;
    
    
    /** * <pre> * 基于Servlet3.0实现动态配置过滤器、监听器、Servlet * </pre> * * <pre> * @author mazq * 修改记录 * 修改后版本: 修改人： 修改日期: 2020/08/27 14:33 修改内容: * </pre> */
    @Component
    public class WebServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer  { 
    
    
        @Override
        protected Class<?>[] getRootConfigClasses() { 
            return new Class[0];
        }
    
        @Override
        protected Class<?>[] getServletConfigClasses() { 
            return new Class[0];
        }
    
        @Override
        protected String[] getServletMappings() { 
            return new String[0];
        }
    
        @Override
        public void onStartup(ServletContext servletContext) throws ServletException { 
            this.registerCasFilter(servletContext);
            this.registerCasListener(servletContext);
            super.onStartup(servletContext);
        }
    
        /** * 动态注册CAS过滤器 * @Author mazq * @Date 2020/08/27 16:41 * @Param [servletContext] * @return void */
        protected void registerCasFilter(ServletContext servletContext) { 
            /* CAS单点登录校验过滤器 */
            FilterRegistration casFilter = servletContext.addFilter("casFilter", AuthenticationFilter.class);
            casFilter.setInitParameter("casServerLoginUrl" , CasPropertiesLoader.getValue(CasParamKeyEnum.CAS_SERVER_HOST_LOGIN_URL.getCasParamKey()));
            casFilter.setInitParameter("serverName" , CasPropertiesLoader.getValue(CasParamKeyEnum.APP_SERVER_HOST_URL.getCasParamKey()));
            casFilter.setInitParameter("ignorePattern" , "/static/*");
            casFilter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class) , true, "/*");
            /* CAS单点登录ticket校验过滤器 */
            FilterRegistration casValidationFilter = servletContext.addFilter("casValidationFilter", Cas30ProxyReceivingTicketValidationFilter.class);
            casValidationFilter.setInitParameter("casServerUrlPrefix" , CasPropertiesLoader.getValue(CasParamKeyEnum.CAS_SERVER_HOST_URL.getCasParamKey()));
            casValidationFilter.setInitParameter("serverName" , CasPropertiesLoader.getValue(CasParamKeyEnum.APP_SERVER_HOST_URL.getCasParamKey()));
            casValidationFilter.setInitParameter("redirectAfterValidation" , "true");
            casValidationFilter.setInitParameter("useSession" , "true");
            casValidationFilter.setInitParameter("encoding" , "UTF-8");
            casValidationFilter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class) , true, "/*");
            /* CAS单点登出过滤器 */
            FilterRegistration singleSignOutFilter = servletContext.addFilter("singleSignOutFilter", SingleSignOutFilter.class);
            singleSignOutFilter.setInitParameter("casServerUrlPrefix" , CasPropertiesLoader.getValue(CasParamKeyEnum.CAS_SERVER_HOST_URL.getCasParamKey()));
            singleSignOutFilter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class) , true, "/*");
            /* HttpServletRequestWrapper过滤器 */
            FilterRegistration httpServletRequestWrapperFilter = servletContext.addFilter("httpServletRequestWrapperFilter", HttpServletRequestWrapperFilter.class);
            httpServletRequestWrapperFilter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class) , true, "/*");
            /* AssertionThreadLocal过滤器 */
            FilterRegistration assertionThreadLocalFilter = servletContext.addFilter("assertionThreadLocalFilter", AssertionThreadLocalFilter.class);
            assertionThreadLocalFilter.addMappingForUrlPatterns(EnumSet.allOf(DispatcherType.class) , true, "/*");
        }
    
        /** * 注册CAS监听器 * @Author mazq * @Date 2020/08/27 16:43 * @Param [servletContext] * @return void */
        protected void registerCasListener(ServletContext servletContext){ 
            //注册监听器
            servletContext.addListener(SingleSignOutHttpSessionListener.class);
        }
    
        @Override
        protected FilterRegistration.Dynamic registerServletFilter(ServletContext servletContext, Filter filter) { 
            return super.registerServletFilter(servletContext, filter);
        }
    
        @Override
        protected void registerContextLoaderListener(ServletContext servletContext) { 
            super.registerContextLoaderListener(servletContext);
        }
    }