最近涉及到了两个项目,都需要考虑全局的拦截器,其功能就是判断session的登陆状态,如果session信息完好,可以从中取得相应的信息,则放行,否则拦截,进入重定向的uri。
既然是全局的拦截器,其拦截的东西当然会很多也就是会很忙,相应的其功能也会非常丰富,可以在其中进行多种功能的拦截,本文就只考虑session的拦截。
以前是使用Filter加一个全局的过滤器,过滤web.xml中配置的url,通过request获取session,如果符合判断条件,则放行,否则做出相应的处理。从原理上来说,使用框架的拦截器跟Filter是一样的,只不过封装的更好,更能更加强大,通用性更强。
从源码上来看:
Filter接口:
public interface Filter { public void init(FilterConfig filterConfig) throws ServletException; public void doFilter ( ServletRequest request, ServletResponse response, FilterChain chain ) throws IOException, ServletException; public void destroy(); }
SpringMVC拦截器接口:
public interface HandlerInterceptor { boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception; void postHandle(
HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
throws Exception; void afterCompletion(
HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
throws Exception; }
struts2拦截器接口:
public interface Interceptor extends Serializable { void destroy(); void init(); String intercept(ActionInvocation invocation) throws Exception;
}
可以看到接口中都是有三个方法,作用就是在做前置工作、本职工作、后续工作。但配置上稍有不同,先谈SpringMVC:
<servlet>
<servlet-name>JeeCmsAdmin</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/config/jeecms-servlet-admin.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>JeeCmsAdmin</servlet-name>
<url-pattern>/jeeadmin/jeecms/*</url-pattern>
</servlet-mapping>
jeecms-servlet-admin.xml(部分)
<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
<property name="interceptors">
<list>
<ref bean="adminContextInterceptor"/>
<ref bean="adminLocaleIntercept"/>
<ref bean="fireWallInterceptor"/>
</list>
</property>
</bean>
<bean id="adminContextInterceptor" class="com.jeecms.cms.web.AdminContextInterceptor">
<property name="auth" value="true"/>
<property name="loginUrl" value="/jeeadmin/jeecms/login.do"/>
<property name="returnUrl" value="/jeeadmin/jeecms/index.do"/>
<property name="excludeUrls">
<list>
<value>/login.do</value>
<value>/logout.do</value>
</list>
</property>
</bean>
<bean id="adminLocaleIntercept" class="com.jeecms.cms.web.AdminLocaleInterceptor"/> <bean id="fireWallInterceptor" class="com.jeecms.cms.web.FireWallInterceptor">
</bean>
AdminContextInterceptor.java(部分)
- /**
- * 在业务处理器处理请求之前被调用
- * 如果返回false
- * 从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
- *
- * 如果返回true
- * 执行下一个拦截器,直到所有的拦截器都执行完毕
- * 再执行被拦截的Controller
- * 然后进入拦截器链,
- * 从最后一个拦截器往回执行所有的postHandle()
- * 接着再从最后一个拦截器往回执行所有的afterCompletion()
- */
public boolean preHandle(HttpServletRequest request,
HttpServletResponse response, Object handler) throws Exception {
// 获得站点
CmsSite site = getSite(request, response);
CmsUtils.setSite(request, site);
// Site加入线程变量
CmsThreadVariable.setSite(site);// 获得用户
CmsUser user = null;
if (adminId != null) {
// 指定管理员(开发状态)
user = cmsUserMng.findById(adminId);
if (user == null) {
throw new IllegalStateException("User ID=" + adminId
+ " not found!");
}
} else {
// 正常状态
Integer userId = authMng
.retrieveUserIdFromSession(session, request);
if (userId != null) {
user = cmsUserMng.findById(userId);
}
}
// 此时用户可以为null
CmsUtils.setUser(request, user);
// User加入线程变量
CmsThreadVariable.setUser(user);String uri = getURI(request);
// 不在验证的范围内
if (exclude(uri)) {
return true;
}
// 用户为null跳转到登陆页面
if (user == null) {
response.sendRedirect(getLoginUrl(request));
return false;
}
// 用户不是管理员,提示无权限。
if (!user.getAdmin()) {
request.setAttribute(MESSAGE, MessageResolver.getMessage(request,
"login.notAdmin"));
response.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
}
// 不属于该站点的管理员,提示无权限。
if (!user.getSites().contains(site)) {
request.setAttribute(MESSAGE, MessageResolver.getMessage(request,
"login.notInSite"));
response.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
}
boolean viewonly = user.getViewonlyAdmin();
// 没有访问权限,提示无权限。
if (auth && !user.isSuper()
&& !permistionPass(uri, user.getPerms(), viewonly)) {
request.setAttribute(MESSAGE, MessageResolver.getMessage(request,
"login.notPermission"));
response.sendError(HttpServletResponse.SC_FORBIDDEN);
return false;
}
return true;
}
struts2的拦截器:
web.xml
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.FilterDispatcher
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
从这个配置可以看出,struts2依然采取过滤器的方式,这个配置与过滤器一模一样,只是struts2进行了若干封装而已。
struts.xml配置:
<struts>
<constant name="struts.objectFactory" value="spring" />
<constant name="struts.devMode" value="true" />
<constant name="struts.i18n.encoding" value="UTF-8"/>
<!-- 全局拦截器 add by fdk -->
<package name="checkLogin" extends="struts-default">
<interceptors>
<interceptor name="noLogin"
class="com.tjhq.exception.AuthorityInterceptor" />
<interceptor-stack name="appStack">
<interceptor-ref name="defaultStack" />(必须加,否则出错)
</interceptor-stack> <interceptor-stack
name="defaultPaginationInterceptorStack">(这句是设置所有Action自动调用的拦截器堆栈)
<interceptor-ref name="noLogin" />
</interceptor-stack>
</interceptors>
<default-interceptor-ref
name="defaultPaginationInterceptorStack" /> <global-results>
<result name="login" type="redirect">${pageContext.request.contextPath}/login.jsp</result>
</global-results>
</package> <package name="strutsCheckLogin" extends="struts-default">
<interceptors>
<interceptor name="noLogin"
class="com.tjhq.exception.AuthorityInterceptor" />
<interceptor-stack name="appStack">
<interceptor-ref name="defaultStack" />
</interceptor-stack>
<interceptor-stack
name="defaultPaginationInterceptorStack">
<interceptor-ref name="noLogin" />
<interceptor-ref name="appStack" />
</interceptor-stack>
</interceptors>
<default-interceptor-ref name="defaultPaginationInterceptorStack" /> <global-results>
<result name="login" type="redirect">${pageContext.request.contextPath}/login.jsp</result>
<result name="noframe" type="redirect">${pageContext.request.contextPath}/pages/error.jsp</result>
</global-results> <global-exception-mappings>
<exception-mapping result="noframe" exception="com.tjhq.exception.AppException"></exception-mapping>
</global-exception-mappings>
</package>
<include file="struts2/pub.xml" />
<include file="struts2/collect.xml" />
<include file="struts2/audit.xml" />
<include file="struts2/publish.xml" />
<include file="struts2/search.xml" />
<include file="struts2/statistics.xml" />
<include file="struts2/sysmanager.xml" />
<include file="struts2/portal.xml" />
<include file="struts2/compre.xml" />
</struts>
AuthorityInterceptor.java
public String intercept(ActionInvocation ai) throws Exception { ActionContext ctx = ai.getInvocationContext();
Map session = ctx.getSession();
if(ServletActionContext.getRequest().getSession().getAttribute(Constants.USER_ID_SESSION)==null){
this.setSessionByUserId(session);
}
String ACCOUNT_ID = (String)session.get(Constants.USER_ID_SESSION);
SysUserBean sb = (SysUserBean)session.get(Constants.USER_ACCOUNT_SESSION);
if(sb != null &&
ACCOUNT_ID != null && ACCOUNT_ID.length()>0){
_logger.info("user loginning");
return ai.invoke();//放行,进入下一个拦截器
}
_logger.info("intercept user is not login");
session.put("message", Dresource.getPropertie(Constants.PropertyKeys.NOT_LOGIN));
return "login";//进入上文蓝色位置
}