如何在SpringWebFilter中添加自定义标头？

我试图在调用REST服务之前添加自定义过滤器。在下面的此类中，我试图在HttpRequest中添加自定义过滤器，但出现错误：-

java.lang.UnsupportedOperationException：在org.springframework.util.CollectionUtils $ MultiValueMapAdapter.add（CollectionUtils.java:459）处的java.util.Collections $ UnmodifiableMap.computeIfAbsent（Collections.java:1535）〜[na：1.8.0_171]为null ）〜[spring-core-5.0.7.RELEASE.jar：5.0.7.RELEASE]

public class AuthenticationWebFilter implements WebFilter {
    private static final Logger LOGGER = LoggerFactory.getLogger(AuthenticationWebFilter.class);

    @Autowired
    private TokenServiceRequest tokenServiceRequest;

    @Autowired
    private AuthenticationProvider authenticationProvider;

    public AuthenticationWebFilter(TokenServiceRequest tokenServiceRequest, AuthenticationProvider authenticationProvider) {
        super();
        this.tokenServiceRequest = tokenServiceRequest;
        this.authenticatiOnProvider= authenticationProvider;
    }

    @Override
    public Mono filter(ServerWebExchange serverWebExchange, WebFilterChain webFilterChain) {
        HttpHeaders requestHeaders = serverWebExchange.getRequest().getHeaders();
        HttpHeaders respOnseHeaders= serverWebExchange.getResponse().getHeaders();
        LOGGER.info("Response HEADERS: "+responseHeaders);
        LOGGER.info("Request HEADERS: "+serverWebExchange.getRequest().getHeaders());

        tokenServiceRequest.setUsername(serverWebExchange.getRequest().getHeaders().getFirst(CommerceConnectorConstants.USERNAME));
        tokenServiceRequest.setPassword(serverWebExchange.getRequest().getHeaders().getFirst(CommerceConnectorConstants.PASSWORD));
        tokenServiceRequest.setClientId(serverWebExchange.getRequest().getHeaders().getFirst(CommerceConnectorConstants.CLIENT_ID));
        tokenServiceRequest.setSecretClient(serverWebExchange.getRequest().getHeaders().getFirst(CommerceConnectorConstants.SECRET_CLIENT));
        LOGGER.info("Token Received: " + authenticationProvider.getUserAccessToken(tokenServiceRequest).getTokenId());

        //responseHeaders.set(CommerceConnectorConstants.X_AUTH_TOKEN, authenticationProvider.getUserAccessToken(tokenServiceRequest).getTokenId());
        //responseHeaders.add(CommerceConnectorConstants.X_AUTH_TOKEN, authenticationProvider.getUserAccessToken(tokenServiceRequest).getTokenId());

        //This below code is not working
        serverWebExchange.getRequest().getQueryParams().add("test", "value");

        //This below code is not working
        //serverWebExchange.getRequest().getHeaders().add(CommerceConnectorConstants.X_AUTH_TOKEN, authenticationProvider.getUserAccessToken(tokenServiceRequest).getTokenId());
        LOGGER.info("Exiting filter@AuthenticationWebFilter");
        return webFilterChain.filter(serverWebExchange);
    }
    }

在HTTPResponse中，我可以设置自定义标头，但我的要求是在HTTPRequest中添加自定义标头。请指教。

如果您在Spring Cloud Gateway中，则可以通过实现GlobalFilter或GatewayFilter修改请求标头。

    @Component 
    public class LogFilter implements GlobalFilter, Ordered {

    private Logger LOG = LoggerFactory.getLogger(LogFilter.class);

    @Override
    public Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        return chain.filter(
                exchange.mutate().request(
                        exchange.getRequest().mutate()
                                .header("customer-header", "customer-header-value")
                                .build())
                        .build());
    }

    @Override
    public int getOrder() {
        return 0;
    } }

如果您在ZuulFilter中，则addZuulRequestHeader可以修改请求标头。

    RequestContext.getCurrentContext().addZuulRequestHeader("customer-header", "customer-header-value");

希望对您有所帮助。