SpringBoot拦截器实现

1. 创建拦截器配置类，实现WebMvcConfigurer接口 重写 addInterceptors方法。

@Configuration
public class h implements WebMvcConfigurer {
    @Autowired
    head head;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(head).excludePathPatterns("*");
        WebMvcConfigurer.super.addInterceptors(registry);
    }
}

2. 拦截处理，创建配置类，实现HandlerInterceptor接口，重写preHandle方法，请求拦截后在此处写业务，返回true放行，反之拦截

@Component
public class head implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("拦截请求");
        PrintWriter writer = response.getWriter();

        Map map = new HashMap<>();
        map.put("String","asdsadas");
        String s = new ObjectMapper().writeValueAsString(map);


        writer.println(s);
        return true;
    }
}