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