一起学习Spring boot 2.1.X | 第十五篇：登陆拦截器

末蓝、 2022-03-29 04:26 369阅读 0赞

## 1.POM依赖 ##

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-aop</artifactId>
            </dependency>

2.新建WebConfig

import com.alibaba.fastjson.JSONObject;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.servlet.HandlerInterceptor;
    import org.springframework.web.servlet.ModelAndView;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
    import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
    import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.IOException;
    
    @Configuration
    public class MvcConfig extends WebMvcConfigurationSupport {
    
        private final static Logger logger = LoggerFactory.getLogger(MvcConfig.class);
    
        //解决跨域问题
        /*@Override
        public void addCorsMappings(CorsRegistry registry) {
    
            registry.addMapping("/**")//配置可以被跨域的路径
                    .allowedMethods("*")//允许所有的请求方法
                    .allowedOrigins("*")//允许所有的请求域名
                    .allowedHeaders("*")//允许所有的请求header访问
                    .allowCredentials(true)//cookie请求的时候需要开启
                    .maxAge(3600)//请求时间
            ;
    
            super.addCorsMappings(registry);
    
        }*/
    
        //拦截器
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
    
            InterceptorRegistration interceptorRegistration = registry.addInterceptor(new LoginInterceptor());
            //excludePathPatterns去除拦截和addPathPatterns添加拦截
            interceptorRegistration.excludePathPatterns("/login"/*,"/page"*/);
    //        interceptorRegistration.excludePathPatterns("/**");
            interceptorRegistration.addPathPatterns("/**");
    
        }
    
        //静态资源处理
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            //需要配置1：需要告知系统，这是要被当成静态文件的！
            //第一个方法设置访问路径前缀，第二个方法设置资源路径
            registry.addResourceHandler("/static/**", "/favicon.ico").addResourceLocations("classpath:/static/");
        }
    
    
        //用户拦截器
        private class LoginInterceptor implements HandlerInterceptor {
    
            @Override
            public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
    
                System.out.println(request.getRequestURI());
                //System.out.println("在控制器执行前调用 ");
    
                //Session
                //Object admin = request.getSession().getAttribute("admin");
    
                //Token
                //String user = request.getHeader("Token");
                //String user = request.getParameter("Token");
                String user = null;
                if (user == null){
                    JSONObject json = new JSONObject();
                    json.put("flag","0");
                    json.put("error","无用户登陆!");
                    //设置缓冲区中使用的编码为UTF-8
                    response.setCharacterEncoding("UTF-8");
                    //设置接受内容时所使用的编码方式
    //                response.setContentType("text/html;charset = UTF-8");
                    response.setContentType("application/json;charset=UTF-8");
                    response.getWriter().print(json);
                    return false;
                }
                logger.info("当前用户已登录，登录的用户名为： ");
                return true;
            }
    
            @Override
            public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
                //controller方法处理完毕后，调用此方法
    //            System.out.println("在后端控制器执行后调用 ");
            }
    
            @Override
            public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
                //页面渲染完毕后调用此方法
    //            System.out.println("整个请求执行完成后调用 ");
            }
        }
    
    }

## 3.需要Controller中重写login ##

@RequestMapping(value = "/login")
        public String admin(){
    
            return "login";
        }

注：自己稍微梳理一下