SpringBoot之WebMvcConfigurer接口

SpringBoot 确实为我们做了很多事情， 但有时候我们想要自己定义一些Handler，Interceptor，ViewResolver时该怎么做呢？在Spring Boot 1.5版本都是靠重写WebMvcConfigurerAdapter的方法来添加自定义拦截器，消息转换器等。SpringBoot 2.0 后，该类被标记为@Deprecated。因此我们只能靠实现WebMvcConfigurer接口来实现。

package com.developlee.config;

import com.alibaba.fastjson.serializer.SerializerFeature;
import com.alibaba.fastjson.support.config.FastJsonConfig;
import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter;
import com.developlee.configurer.USLocalDateFormatter;
import org.springframework.format.FormatterRegistry;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.JsonbHttpMessageConverter;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

/**
 * @Description 实现WebMvcConfigurer接口，
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

    /**
     * 添加类型转换器和格式化器
     * @param registry
     */
    @Override
    public void addFormatters(FormatterRegistry registry) {
        registry.addFormatterForFieldType(LocalDate.class, new USLocalDateFormatter())
                 .excludePathPatterns("/login");
    }

    /**
     * 跨域支持
     * @param registry
     */
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowCredentials(true)
                .allowedMethods("GET", "POST", "DELETE", "PUT")
                .maxAge(3600 * 24);
    }

   /**
    * 拦截器设置
    */
  @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //对所有请求进行拦截
        registry.addInterceptor(new ReqInterceptor()).addPathPatterns("/**");
    }
}

添加一个Interceptor类：

package com.developlee.configurer;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

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

/**
 * @Description 请求Interceptor
 */
public class ReqInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("Interceptor preHandler method is running !");
        return super.preHandle(request, response, handler);
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("Interceptor postHandler method is running !");
        super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("Interceptor afterCompletion method is running !");
        super.afterCompletion(request, response, handler, ex);
    }
}

 

可以通过拦截除登录和鉴权的方法进行安全拦截(token检验，没有登录拒绝访问),过期重新登录(授权过期，重新登录)，
检查踢下线等。