在java开发中,拦截器使用是很普遍的,最常用的就是登陆拦截了,然后并不是所有的请求我们都需要拦截,比如index页面的请求我们是不拦截的.通常情况下我们有两种方式:先贴出来springboot使用拦截器的case:

1.自定义拦截器,实现HandlerInterceptor ,也可以采用继承的方式(HandlerInterceptorAdapter),内容不重要,看过程

public class LoginHandlerInterceptor implements HandlerInterceptor {

public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

HttpSession session = request.getSession();

String username = (String) session.getAttribute("username");

if (StringUtils.isEmpty(username) || !Objects.equals("123456",username)) {

request.setAttribute("msg","没有权限");

request.getRequestDispatcher("/index.html").forward(request,response);

return false;

}else {

return true;

}

}

public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {

}

public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {

}

}

2.配置我们自定义的拦截器

@Configuration

public class MyConfigurerAdapter extends WebMvcConfigurerAdapter {

@Override

public void addInterceptors(InterceptorRegistry registry) {

registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("*").excludePathPatterns("/index","/","/user/login");

super.addInterceptors(registry);

}

}

第一种方式就是使用interceptor的excludePatterns来去除我们不要验证的请求

第二种方式是使用注解的方式(虽然这个麻烦一点点,但是使用方便)

@Target(ElementType.METHOD)

@Retention(RetentionPolicy.RUNTIME)

public @interface UnAuthRequest {

}

然后我们自己的拦截器就需要改一下

public class LoginHandlerInterceptor implements HandlerInterceptor {

public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

HttpSession session = request.getSession();

HandlerMethod handlerMethod = (HandlerMethod) handler;

Method method = handlerMethod.getMethod();

UnAuthRequest annotation = method.getAnnotation(UnAuthRequest.class);

if (Objects.nonNull(annotation)) {

return true;

}

String username = (String) session.getAttribute("username");

if (StringUtils.isEmpty(username) || !Objects.equals("123456",username)) {

request.setAttribute("msg","没有权限");

request.getRequestDispatcher("/index.html").forward(request,response);

return false;

}else {

return true;

}

}

public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {

}

public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {

}

}

这样的话,我们只需要将注解贴在我们不需要拦截的请求上就行了,使用起来很方便.