wxiangliang

``` .route("user_route",r->r.path("/user") .filters( f->f.setRequestHeader("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE) .modifyRequestBody(MultiValueMap.class,MultiValueMap.class,((serverWebExchange, user) -> { MultiValueMap formData = new LinkedMultiValueMap(); formData.add("username", "John"); formData.add("nickName", "qwerty"); return Mono.just(formData); })) ) .uri("lb://smweb")) ``` ``` java.lang.UnsupportedOperationException: null at java.util.Collections$UnmodifiableMap.put(Collections.java:1457) ~[na:1.8.0_144]...