ssm框架拦截器

1.ssm框架的拦截器是在springmvc-servlet.xml配置文件中进行配置

<!-- 拦截器 -->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**" />
            <bean class="cn.com.***.controller.common.SecurityInterceptor">
                <!-- 不需要session验证的地址 -->
                <property name="excludeUrls">
                    <list>
                        <value>/web/index</value>
                        <value>/web/aboutsPage</value>                                              
                    </list>
                </property>
            </bean>
        </mvc:interceptor>
    </mvc:interceptors>

2.创建一个拦截器实体类，继承HandlerInterceptor，重写它的方法，preHandle是调用Controller具体方法之前拦截，postHandle是调用Controller具体方法之后拦截，afterCompletion是完成页面后调用，所以在preHandle里面写逻辑代码，如登入之后怎么做，没登录这么做，或者根据不同的登录平台进行跳转之类的逻辑

package cn.com.***.controller.common;

import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import cn.com.***.common.pojo.WSessionInfo;
import cn.com.***.common.result.Constant;


/**
 * 权限拦截器
 */
public class SecurityInterceptor implements HandlerInterceptor {

    private List<String> excludeUrls;// 不需要拦截的资源
    private List<String> wapUrls;//wapurl
    
    public List<String> getWapUrls() {
        return wapUrls;
    }

    public void setWapUrls(List<String> wapUrls) {
        this.wapUrls = wapUrls;
    }

    public List<String> getExcludeUrls() {
        return excludeUrls;
    }

    public void setExcludeUrls(List<String> excludeUrls) {
        this.excludeUrls = excludeUrls;
    }

    /**
     * 完成页面的render后调用
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object object,
            Exception exception) throws Exception {
    }

    /**
     * 在调用controller具体方法后拦截
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object object,
            ModelAndView modelAndView) throws Exception {
    }

    /**
     * 在调用controller具体方法前拦截
     */
    @SuppressWarnings("unchecked")
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object object) throws Exception {
         //请求的路径
        String contextPath=request.getContextPath();
        String  url=request.getServletPath().toString();
        StringBuffer realUrl = request.getRequestURL();
        WSessionInfo sessionInfo = (WSessionInfo) request.getSession().getAttribute(Constant.SESSION_INFO);

          if(excludeUrls.contains(url)){
              return true ;
          }

if (sessionInfo == null) {
            String isqian = url.substring(0, 4);
            if (isqian.equals("/wap")) {
              response.sendRedirect(contextPath + "/wap/adminLogin");
              return true;
            }if (isqian.equals("/web")) {
              response.sendRedirect(contextPath + "/web/index");
            } else if (realUrl.toString().equals(contextPath +"/web/index")) {
              response.sendRedirect(contextPath + "/wap/adminLogin");
              return true;
            }
          }
        return true ;
        
    }
}