spring cloud中FeignClientFactoryBean的原理和作用是什么
这篇文章主要介绍"spring cloud中FeignClientFactoryBean的原理和作用是什么"，在日常操作中，相信很多人在spring cloud中FeignClientFactoryBean的原理和作用是什么问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"spring cloud中FeignClientFactoryBean的原理和作用是什么"的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
序
本文主要研究一下spring cloud的FeignClientFactoryBean
FeignClientFactoryBean
spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/FeignClientFactoryBean.java
class FeignClientFactoryBean implements FactoryBean
FeignClientFactoryBean实现了FactoryBean的getObject、getObjectType、isSingleton方法；实现了InitializingBean的afterPropertiesSet方法；实现了ApplicationContextAware的setApplicationContext方法
getObject调用的是getTarget方法，它从applicationContext取出FeignContext，然后构造Feign.Builder并设置了logger、encoder、decoder、contract，之后通过configureFeign根据FeignClientProperties来进一步配置Feign.Builder的retryer、errorDecoder、request.Options、requestInterceptors、queryMapEncoder、decode404
初步配置完Feign.Builder之后再判断是否需要loadBalance，如果需要则通过loadBalance方法来设置，不需要则在Client是LoadBalancerFeignClient的时候进行unwrap
FeignClientProperties
spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/FeignClientProperties.java
@ConfigurationProperties("feign.client")public class FeignClientProperties { private boolean defaultToProperties = true; private String defaultConfig = "default"; private Map config = new HashMap<>(); public boolean isDefaultToProperties() { return this.defaultToProperties; } public void setDefaultToProperties(boolean defaultToProperties) { this.defaultToProperties = defaultToProperties; } public String getDefaultConfig() { return this.defaultConfig; } public void setDefaultConfig(String defaultConfig) { this.defaultConfig = defaultConfig; } public Map getConfig() { return this.config; } public void setConfig(Map config) { this.config = config; } @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } FeignClientProperties that = (FeignClientProperties) o; return this.defaultToProperties == that.defaultToProperties && Objects.equals(this.defaultConfig, that.defaultConfig) && Objects.equals(this.config, that.config); } @Override public int hashCode() { return Objects.hash(this.defaultToProperties, this.defaultConfig, this.config); } /** * Feign client configuration. */ public static class FeignClientConfiguration { private Logger.Level loggerLevel; private Integer connectTimeout; private Integer readTimeout; private Class retryer; private Class errorDecoder; private List> requestInterceptors; private Boolean decode404; private Class decoder; private Class encoder; private Class contract; public Logger.Level getLoggerLevel() { return this.loggerLevel; } public void setLoggerLevel(Logger.Level loggerLevel) { this.loggerLevel = loggerLevel; } public Integer getConnectTimeout() { return this.connectTimeout; } public void setConnectTimeout(Integer connectTimeout) { this.connectTimeout = connectTimeout; } public Integer getReadTimeout() { return this.readTimeout; } public void setReadTimeout(Integer readTimeout) { this.readTimeout = readTimeout; } public Class getRetryer() { return this.retryer; } public void setRetryer(Class retryer) { this.retryer = retryer; } public Class getErrorDecoder() { return this.errorDecoder; } public void setErrorDecoder(Class errorDecoder) { this.errorDecoder = errorDecoder; } public List> getRequestInterceptors() { return this.requestInterceptors; } public void setRequestInterceptors( List> requestInterceptors) { this.requestInterceptors = requestInterceptors; } public Boolean getDecode404() { return this.decode404; } public void setDecode404(Boolean decode404) { this.decode404 = decode404; } public Class getDecoder() { return this.decoder; } public void setDecoder(Class decoder) { this.decoder = decoder; } public Class getEncoder() { return this.encoder; } public void setEncoder(Class encoder) { this.encoder = encoder; } public Class getContract() { return this.contract; } public void setContract(Class contract) { this.contract = contract; } @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } FeignClientConfiguration that = (FeignClientConfiguration) o; return this.loggerLevel == that.loggerLevel && Objects.equals(this.connectTimeout, that.connectTimeout) && Objects.equals(this.readTimeout, that.readTimeout) && Objects.equals(this.retryer, that.retryer) && Objects.equals(this.errorDecoder, that.errorDecoder) && Objects.equals(this.requestInterceptors, that.requestInterceptors) && Objects.equals(this.decode404, that.decode404) && Objects.equals(this.encoder, that.encoder) && Objects.equals(this.decoder, that.decoder) && Objects.equals(this.contract, that.contract); } @Override public int hashCode() { return Objects.hash(this.loggerLevel, this.connectTimeout, this.readTimeout, this.retryer, this.errorDecoder, this.requestInterceptors, this.decode404, this.encoder, this.decoder, this.contract); } }} FeignClientProperties有个Map结构的config，key是feign client的名称，默认是default，value是FeignClientConfiguration；FeignClientConfiguration包含了loggerLevel、connectTimeout、readTimeout、retryer、errorDecoder、requestInterceptors、decode404、decoder、encoder、contract属性
小结
FeignClientFactoryBean实现了FactoryBean的getObject、getObjectType、isSingleton方法；实现了InitializingBean的afterPropertiesSet方法；实现了ApplicationContextAware的setApplicationContext方法
getObject调用的是getTarget方法，它从applicationContext取出FeignContext，然后构造Feign.Builder并设置了logger、encoder、decoder、contract，之后通过configureFeign根据FeignClientProperties来进一步配置Feign.Builder的retryer、errorDecoder、request.Options、requestInterceptors、queryMapEncoder、decode404
初步配置完Feign.Builder之后再判断是否需要loadBalance，如果需要则通过loadBalance方法来设置，不需要则在Client是LoadBalancerFeignClient的时候进行unwrap
到此，关于"spring cloud中FeignClientFactoryBean的原理和作用是什么"的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注网站，小编会继续努力为大家带来更多实用的文章！
