springboot使用handlerintercpteradapter自定义拦截器

以用户登录拦截验证为例

1.创建一个自定义的登录拦截器LoginInterCeptor

//编程方法被调用之前

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    String path = request.getServletPath();
    //验证session
    Object username = request.getSession().getAttribute("username");
    if(username !=null){
        return true;
    }
    //如果为空就去登录
    else {
        response.sendRedirect("/user/login");
        return  false;
    }
}

2.配置WebMvcConfigurer,将自定义类加入到配置中

@Configuration
public class WebConfigurer implements WebMvcConfigurer {
    private static final List<String> EXCLUDE_PATH= Arrays.asList("/","/css/**","/js/**","/img/**");
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //配置拦截所有请求
        registry.addInterceptor(LoginInterCeptor()).addPathPatterns("/**"). excludePathPatterns(EXCLUDE_PATH);

    }
    @Bean
    public  LoginInterCeptor LoginInterCeptor(){

        return new LoginInterCeptor();
    }

}

 3.注意EXCLUDE_PATH

EXCLUDE_PATH常量为过滤器放行规则，如果改为

. excludePathPatterns("/static/**");是不生效的

4.还可以引入注解的方式

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginRequired {
}
我用的第一种方式，注解方式就不多做赘述