Spring WebFlux 是一个基于spring 5+的reactive web 框架，filters 的实现和以前的spring mvc不一样，基本没有(Servlet Filter, HandlerInterceptor）这些了，而是全新的weblux风格的过滤器，下面介绍几种实现方式：
方法一：WebFilter
函数式的router风格：https://docs.spring.io/spring/docs/current/spring-framework-reference/web-reactive.html#webflux-fn
WebFilter 的 Kotlin 实现：
@Bean
fun sampleWebFilter(): WebFilter {
return WebFilter { e: ServerWebExchange, c: WebFilterChain ->
val l: MutableList<String> = e.getAttributeOrDefault(KEY, mutableListOf())
l.add("From WebFilter")
e.attributes.put(KEY, l) // 目前发现attributes不能放mono和flux的对象
c.filter(e)
}
}
方法二：HandlerFilterFunction
基于函数式的路由方式，RouterFunctions提供钩子实现
@Bean
fun route(): RouterFunction<*> = router {
GET("/react/hello", { r ->
ok().body(fromObject(
Greeting("${r.attribute(KEY).orElse("[Fallback]: ")}: Hello")
))
POST("/another/endpoint", TODO())
PUT("/another/endpoint", TODO())
})
}
HandlerFilterFunction 拦截请求：
fun route(): RouterFunction<*> = router {
GET("/react/hello", { r ->
ok().body(fromObject(
Greeting("${r.attribute(KEY).orElse("[Fallback]: ")}: Hello")
))
})
POST("/another/endpoint", TODO())
PUT("/another/endpoint", TODO())
}.filter({ r: ServerRequest, n: HandlerFunction<ServerResponse> ->
val greetings: MutableList<String> = r.attribute(KEY)
.map { v ->
v as MutableList<String>
}.orElse(mutableListOf())
greetings.add("From HandlerFilterFunction")
r.attributes().put(KEY, greetings)
n.handle(r)
})
github:https://github.com/xlj44400/sample-webflux-web-testing
