spring cloud的FeignLoadBalancer怎么用

本篇内容主要讲解"spring cloud的FeignLoadBalancer怎么用"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"spring cloud的FeignLoadBalancer怎么用"吧!

序

本文主要研究一下spring cloud的FeignLoadBalancer

FeignLoadBalancer

spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/ribbon/FeignLoadBalancer.java

public class FeignLoadBalancer extends                AbstractLoadBalancerAwareClient {        private final RibbonProperties ribbon;        protected int connectTimeout;        protected int readTimeout;        protected IClientConfig clientConfig;        protected ServerIntrospector serverIntrospector;        public FeignLoadBalancer(ILoadBalancer lb, IClientConfig clientConfig,                        ServerIntrospector serverIntrospector) {                super(lb, clientConfig);                this.setRetryHandler(RetryHandler.DEFAULT);                this.clientConfig = clientConfig;                this.ribbon = RibbonProperties.from(clientConfig);                RibbonProperties ribbon = this.ribbon;                this.connectTimeout = ribbon.getConnectTimeout();                this.readTimeout = ribbon.getReadTimeout();                this.serverIntrospector = serverIntrospector;        }        @Override        public RibbonResponse execute(RibbonRequest request, IClientConfig configOverride)                        throws IOException {                Request.Options options;                if (configOverride != null) {                        RibbonProperties override = RibbonProperties.from(configOverride);                        options = new Request.Options(override.connectTimeout(this.connectTimeout),                                        override.readTimeout(this.readTimeout));                }                else {                        options = new Request.Options(this.connectTimeout, this.readTimeout);                }                Response response = request.client().execute(request.toRequest(), options);                return new RibbonResponse(request.getUri(), response);        }        @Override        public RequestSpecificRetryHandler getRequestSpecificRetryHandler(                        RibbonRequest request, IClientConfig requestConfig) {                if (this.ribbon.isOkToRetryOnAllOperations()) {                        return new RequestSpecificRetryHandler(true, true, this.getRetryHandler(),                                        requestConfig);                }                if (!request.toRequest().httpMethod().name().equals("GET")) {                        return new RequestSpecificRetryHandler(true, false, this.getRetryHandler(),                                        requestConfig);                }                else {                        return new RequestSpecificRetryHandler(true, true, this.getRetryHandler(),                                        requestConfig);                }        }        @Override        public URI reconstructURIWithServer(Server server, URI original) {                URI uri = updateToSecureConnectionIfNeeded(original, this.clientConfig,                                this.serverIntrospector, server);                return super.reconstructURIWithServer(server, uri);        }        //......}

• FeignLoadBalancer继承了AbstractLoadBalancerAwareClient，它的构造器接收ILoadBalancer、IClientConfig、ServerIntrospector，设置的retryHandler为RetryHandler.DEFAULT

• 其execute方法首先构造Request.Options，然后通过request.client().execute来获取Response，最后返回RibbonResponse

• FeignLoadBalancer还覆盖了getRequestSpecificRetryHandler方法，针对ribbon.isOkToRetryOnAllOperations()来构建不同的RequestSpecificRetryHandler；还覆盖了reconstructURIWithServer方法，它使用RibbonUtils的updateToSecureConnectionIfNeeded来构建URI

RibbonRequest

spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/ribbon/FeignLoadBalancer.java

        protected static class RibbonRequest extends ClientRequest implements Cloneable {                private final Request request;                private final Client client;                protected RibbonRequest(Client client, Request request, URI uri) {                        this.client = client;                        setUri(uri);                        this.request = toRequest(request);                }                private Request toRequest(Request request) {                        Map> headers = new LinkedHashMap<>(                                        request.headers());                        return Request.create(request.httpMethod(), getUri().toASCIIString(), headers,                                        request.requestBody());                }                Request toRequest() {                        return toRequest(this.request);                }                Client client() {                        return this.client;                }                HttpRequest toHttpRequest() {                        return new HttpRequest() {                                @Override                                public HttpMethod getMethod() {                                        return HttpMethod                                                        .resolve(RibbonRequest.this.toRequest().httpMethod().name());                                }                                @Override                                public String getMethodValue() {                                        return getMethod().name();                                }                                @Override                                public URI getURI() {                                        return RibbonRequest.this.getUri();                                }                                @Override                                public HttpHeaders getHeaders() {                                        Map> headers = new HashMap<>();                                        Map> feignHeaders = RibbonRequest.this                                                        .toRequest().headers();                                        for (String key : feignHeaders.keySet()) {                                                headers.put(key, new ArrayList(feignHeaders.get(key)));                                        }                                        HttpHeaders httpHeaders = new HttpHeaders();                                        httpHeaders.putAll(headers);                                        return httpHeaders;                                }                        };                }                public Request getRequest() {                        return this.request;                }                public Client getClient() {                        return this.client;                }                @Override                public Object clone() {                        return new RibbonRequest(this.client, this.request, getUri());                }        }

• RibbonRequest继承了ClientRequest实现了Cloneable接口，它提供了toHttpRequest方法来将feign的Request转换为spring的HttpRequest

RibbonResponse

spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/ribbon/FeignLoadBalancer.java

   protected static class RibbonResponse implements IResponse {                private final URI uri;                private final Response response;                protected RibbonResponse(URI uri, Response response) {                        this.uri = uri;                        this.response = response;                }                @Override                public Object getPayload() throws ClientException {                        return this.response.body();                }                @Override                public boolean hasPayload() {                        return this.response.body() != null;                }                @Override                public boolean isSuccess() {                        return this.response.status() == 200;                }                @Override                public URI getRequestedURI() {                        return this.uri;                }                @Override                public Map> getHeaders() {                        return this.response.headers();                }                Response toResponse() {                        return this.response;                }                @Override                public void close() throws IOException {                        if (this.response != null && this.response.body() != null) {                                this.response.body().close();                        }                }        }

• RibbonResponse实现了IResponse接口，将feign的Response适配为netflix的IResponse

小结

• FeignLoadBalancer继承了AbstractLoadBalancerAwareClient，它的构造器接收ILoadBalancer、IClientConfig、ServerIntrospector，设置的retryHandler为RetryHandler.DEFAULT

• 其execute方法首先构造Request.Options，然后通过request.client().execute来获取Response，最后返回RibbonResponse

• FeignLoadBalancer还覆盖了getRequestSpecificRetryHandler方法，针对ribbon.isOkToRetryOnAllOperations()来构建不同的RequestSpecificRetryHandler；还覆盖了reconstructURIWithServer方法，它使用RibbonUtils的updateToSecureConnectionIfNeeded来构建URI

到此，相信大家对"spring cloud的FeignLoadBalancer怎么用"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！