[Java知识库]spring项目中配置MVC拦截器

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:task="http://www.springframework.org/schema/task" 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd
       http://www.springframework.org/schema/task  
       http://www.springframework.org/schema/task/spring-task-3.2.xsd">
    <mvc:default-servlet-handler/>

    <!-- Controller包(自动注入) -->
    <context:component-scan base-package="com.**.controller"/>
    
    <!-- 配置拦截器 -->
<mvc:interceptors>
    <!-- 配置一个全局拦截器，拦截所有请求 -->
    <mvc:interceptor>
        <!-- 配置拦截器作用的路径 -->
        <mvc:mapping path="/**" />
        <!-- 配置不需要拦截作用的路径 -->
        <mvc:exclude-mapping path="/" />
        <mvc:exclude-mapping path="/login" />
        <!-- 定义<mvc:interceptor>元素中，表示匹配指定路径的请求才进行拦截 -->
        <bean class="com.hwxx.common.web.AccessInterceptor" />
    </mvc:interceptor>
</mvc:interceptors>

先配置xml中的配置类,然后再 创建?/eam/src/main/java/com/hwxx/common/web/AccessInterceptor.java 类

package com.hwxx.common.web;

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

import org.springframework.web.servlet.HandlerInterceptor;

import com.hwxx.system.entity.SysUsers;


/**
 *  MVC拦截器- 拦截所有的页面- 除了login 登录页面
 * @author 
 * 2022-3-13
 */
public class AccessInterceptor implements HandlerInterceptor{
	
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {
            String url = request.getRequestURL().toString();  
            if(url.endsWith("/login") || url.endsWith("/") || url.endsWith("/index"))
                return true;
            //判断是否已经登录
            HttpSession session = request.getSession();
            SysUsers sysUsers = (SysUsers)session.getAttribute("sysUsers"); 
            if(sysUsers == null) {
                response.sendRedirect("http://localhost/eam/login");  
            }  
		System.out.println("MVC拦截器111111111");    
		return false; //false拦截所有的, true是放行
	}
}

还有一种方法: 是通过注解配置类的方式拦截,这两种二选其一

package com.hwxx.common.web;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class SpringMebConfig implements WebMvcConfigurer{
	//配置spring mvc拦截器
	@Override
	public void addInterceptors(InterceptorRegistry registry) {
		registry.addInterceptor(new AccessInterceptor())
				.addPathPatterns("/**")
				.excludePathPatterns("/login");  //放行哪个不拦截
	}
}