1. 自定义拦截器
实现HandlerInterceptor接口
拦截器一:
package cn.rodge.ssm.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
/**
* 自定义拦截器1
* @author Rodge
*
*/
public class Interceptor_First implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
//判断用户是否登录,即session中是否有值
//如果用户登录,放行return true
//如果没登录,页面转发,拦截
System.out.println("Interceptor_first preHandler");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
ModelAndView modelAndView) throws Exception {
System.out.println("Interceptor_first postHandler");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
throws Exception {
System.out.println("Interceptor_first afterCompletion");
}
}
拦截器二:
public class Interceptor_Second implements HandlerInterceptor {......}
拦截器三
public class Interceptor_Third implements HandlerInterceptor {......}
2. 拦截器的配置
2.1 针对某种mapping进行拦截
<bean
class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping">
<property name="interceptors">
<list>
<ref bean="handlerInterceptor1"/>
<ref bean="handlerInterceptor2"/>
</list>
</property>
</bean>
<bean id="handlerInterceptor1" class="springmvc.intercapter.HandlerInterceptor1"/>
<bean id="handlerInterceptor2" class="springmvc.intercapter.HandlerInterceptor2"/>
2.2 全局拦截器
<!-- 配置拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="cn.rodge.ssm.interceptor.Interceptor_First"></bean>
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="cn.rodge.ssm.interceptor.Interceptor_Second"></bean>
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="cn.rodge.ssm.interceptor.Interceptor_Third"></bean>
</mvc:interceptor>
</mvc:interceptors>
web.xml中的配置
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>
<!-- 需要在前端控制器中添加过滤路径 -->
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
3. 拦截器的执行流程
preHandle按拦截器定义顺序调用
postHandler按拦截器定义逆序调用
afterCompletion按拦截器定义逆序调用
postHandler在拦截器链内所有拦截器返成功调用
afterCompletion只有preHandle返回true才调用
4. 拦截器应用实例
用户身份认证
4.1 拦截器的编写
package cn.rodge.ssm.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
/**
* 自定义拦截器1
* @author Rodge
*
*/
public class LoginInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
//如果是登录界面,放行
String requestURI = request.getRequestURI();
System.out.println("请求uri路径" + requestURI);
if (requestURI.contains("login")) {
return true;
}
//判断用户是否登录,即session中是否有值
HttpSession session = request.getSession();
Object object = session.getAttribute("username");
if (object != null) {
//如果用户登录,放行return true
return true;
} else {
//如果没登录,页面转发,拦截
System.out.println("工程名: " + request.getContextPath());
request.getRequestDispatcher("WEB-INF/jsp/login.jsp").forward(request, response);
return false;
}
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
ModelAndView modelAndView) throws Exception {
System.out.println("Interceptor_Third postHandler");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
throws Exception {
System.out.println("Interceptor_Third afterCompletion");
}
}
4.2 拦截器的配置
在springmvc.xml中的配置
<!-- 配置静态资源访问:解决springmvc拦截js的问题 -->
<mvc:resources location="/js/" mapping="/js/**"/>
<!-- 配置拦截器 -->
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="cn.rodge.ssm.interceptor.LoginInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>
web.xml中的配置
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
