聊聊spring cloud的FeignClientBuilder-优快云博客

本文详细探讨了Spring Cloud中的FeignClientBuilder，包括它的forType方法、Builder构造及其实例应用。通过FeignClientBuilder，可以方便地创建并配置Feign客户端。文章还提到了FeignClientFactoryBean在构建feign client过程中的作用。

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本文主要研究一下spring cloud的FeignClientBuilder

FeignClientBuilder

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

public class FeignClientBuilder {

	private final ApplicationContext applicationContext;

	public FeignClientBuilder(final ApplicationContext applicationContext) {
		this.applicationContext = applicationContext;
	}

	public <T> Builder<T> forType(final Class<T> type, final String name) {
		return new Builder<>(this.applicationContext, type, name);
	}

	/**
	 * Builder of feign targets.
	 *
	 * @param <T> type of target
	 */
	public static final class Builder<T> {

		private FeignClientFactoryBean feignClientFactoryBean;

		private Builder(final ApplicationContext applicationContext, final Class<T> type,
				final String name) {
			this.feignClientFactoryBean = new FeignClientFactoryBean();

			this.feignClientFactoryBean.setApplicationContext(applicationContext);
			this.feignClientFactoryBean.setType(type);
			this.feignClientFactoryBean.setName(FeignClientsRegistrar.getName(name));
			this.feignClientFactoryBean.setContextId(FeignClientsRegistrar.getName(name));
			// preset default values - these values resemble the default values on the
			// FeignClient annotation
			this.url("").path("").decode404(false).fallback(void.class)
					.fallbackFactory(void.class);
		}

		public Builder url(final String url) {
			this.feignClientFactoryBean.setUrl(FeignClientsRegistrar.getUrl(url));
			return this;
		}

		public Builder contextId(final String contextId) {
			this.feignClientFactoryBean.set