springmvc 过滤器和拦截器

 1. 拦截器:

interceptor

过滤器(filter)与拦截器(intercepter)相同点:
1) 都可以拦截请求,过滤请求
2) 都是应用了过滤器(责任链)设计模式

2.区别:

1) filter是范围比较大,配置web.xml中

2) intercepter范围比较小,配置在springmvc中

3) 在进入springmvc处理之前,要先处理web.xml的

springmvc-servlet.txml

   <bean id="localeResolver"
          class="org.springframework.web.servlet.i18n.SessionLocaleResolver"></bean>
    <mvc:interceptors>
        <!--<bean class="com.etc.interceptor.LoginInterceptor.etc.interceptor.MyInterceptor"></bean>-->
        <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"></bean>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <mvc:exclude-mapping path="/login"/>
            <bean class="com.etc.interceptor.LoginInterceptor"/>
        </mvc:interceptor>
    </mvc:interceptors>

 

web.xml

    <filter>
        <filter-name>loginFilter</filter-name>
        <filter-class>com.etc.fileter.MyFileter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>loginFilter</filter-name>
        <url-pattern>/</url-pattern>
    </filter-mapping>

LoginInterceptor:

package com.etc.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        HttpSession session=httpServletRequest.getSession();
        if(session.getAttribute("login")==null){
            httpServletResponse.sendRedirect("/login");
            return false;
        }else {
            System.out.println("ip:"+httpServletRequest.getRemoteHost()+"url"+httpServletRequest.getRequestURL()) ;
            return true;
        }
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

MyFileter:

package com.etc.fileter;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class MyFileter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
// 实际
        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
        HttpServletResponse httpServletResponse = (HttpServletResponse) servletResponse;

        // 如果调用了这个方法,过滤器就会继承往下执行,
        HttpSession session = httpServletRequest.getSession();
        if (session.getAttribute("login") == null) {
            //没有登陆
            httpServletResponse.sendRedirect("/login");
            //return false;
        } else {
            System.out.println("ip:" + httpServletRequest.getRemoteHost() + ",url:" + httpServletRequest.getRequestURL());
            filterChain.doFilter(servletRequest, servletResponse);
            //return true;
        }

    }

    @Override
    public void destroy() {

    }
}