spring cloud的FeignLoadBalancer怎么用

本篇內(nèi)容主要講解“spring cloud的FeignLoadBalancer怎么用”，感興趣的朋友不妨來看看。本文介紹的方法操作簡單快捷，實(shí)用性強(qiáng)。下面就讓小編來帶大家學(xué)習(xí)“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<FeignLoadBalancer.RibbonRequest, FeignLoadBalancer.RibbonResponse> {

	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繼承了AbstractLoadBalancerAwareClient，它的構(gòu)造器接收ILoadBalancer、IClientConfig、ServerIntrospector，設(shè)置的retryHandler為RetryHandler.DEFAULT

• 其execute方法首先構(gòu)造Request.Options，然后通過request.client().execute來獲取Response，最后返回RibbonResponse

• FeignLoadBalancer還覆蓋了getRequestSpecificRetryHandler方法，針對(duì)ribbon.isOkToRetryOnAllOperations()來構(gòu)建不同的RequestSpecificRetryHandler；還覆蓋了reconstructURIWithServer方法，它使用RibbonUtils的updateToSecureConnectionIfNeeded來構(gòu)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<String, Collection<String>> 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<String, List<String>> headers = new HashMap<>();
					Map<String, Collection<String>> feignHeaders = RibbonRequest.this
							.toRequest().headers();
					for (String key : feignHeaders.keySet()) {
						headers.put(key, new ArrayList<String>(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繼承了ClientRequest實(shí)現(xiàn)了Cloneable接口，它提供了toHttpRequest方法來將feign的Request轉(zhuǎn)換為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<String, Collection<String>> 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實(shí)現(xiàn)了IResponse接口，將feign的Response適配為netflix的IResponse

小結(jié)

• FeignLoadBalancer繼承了AbstractLoadBalancerAwareClient，它的構(gòu)造器接收ILoadBalancer、IClientConfig、ServerIntrospector，設(shè)置的retryHandler為RetryHandler.DEFAULT

• 其execute方法首先構(gòu)造Request.Options，然后通過request.client().execute來獲取Response，最后返回RibbonResponse

• FeignLoadBalancer還覆蓋了getRequestSpecificRetryHandler方法，針對(duì)ribbon.isOkToRetryOnAllOperations()來構(gòu)建不同的RequestSpecificRetryHandler；還覆蓋了reconstructURIWithServer方法，它使用RibbonUtils的updateToSecureConnectionIfNeeded來構(gòu)建URI

到此，相信大家對(duì)“spring cloud的FeignLoadBalancer怎么用”有了更深的了解，不妨來實(shí)際操作一番吧！這里是億速云網(wǎng)站，更多相關(guān)內(nèi)容可以進(jìn)入相關(guān)頻道進(jìn)行查詢，關(guān)注我們，繼續(xù)學(xué)習(xí)！