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！
本文主要研究一下spring cloud的FeignClientFactoryBean
spring-cloud-openfeign-core-2.2.0.M1-sources.jar!/org/springframework/cloud/openfeign/FeignClientFactoryBean.java
class FeignClientFactoryBean
implements FactoryBean<Object>, InitializingBean, ApplicationContextAware {
/***********************************
* WARNING! Nothing in this class should be @Autowired. It causes NPEs because of some
* lifecycle race condition.
***********************************/
private Class<?> type;
private String name;
private String url;
private String contextId;
private String path;
private boolean decode404;
private ApplicationContext applicationContext;
private Class<?> fallback = void.class;
private Class<?> fallbackFactory = void.class;
@Override
public void afterPropertiesSet() throws Exception {
Assert.hasText(this.contextId, "Context id must be set");
Assert.hasText(this.name, "Name must be set");
}
@Override
public Object getObject() throws Exception {
return getTarget();
}
@Override
public Class<?> getObjectType() {
return this.type;
}
@Override
public boolean isSingleton() {
return true;
}
@Override
public void setApplicationContext(ApplicationContext context) throws BeansException {
this.applicationContext = context;
}
<T> T getTarget() {
FeignContext context = this.applicationContext.getBean(FeignContext.class);
Feign.Builder builder = feign(context);
if (!StringUtils.hasText(this.url)) {
if (!this.name.startsWith("http")) {
this.url = "http://" + this.name;
}
else {
this.url = this.name;
}
this.url += cleanPath();
return (T) loadBalance(builder, context,
new HardCodedTarget<>(this.type, this.name, this.url));
}
if (StringUtils.hasText(this.url) && !this.url.startsWith("http")) {
this.url = "http://" + this.url;
}
String url = this.url + cleanPath();
Client client = getOptional(context, Client.class);
if (client != null) {
if (client instanceof LoadBalancerFeignClient) {
// not load balancing because we have a url,
// but ribbon is on the classpath, so unwrap
client = ((LoadBalancerFeignClient) client).getDelegate();
}
builder.client(client);
}
Targeter targeter = get(context, Targeter.class);
return (T) targeter.target(this, builder, context,
new HardCodedTarget<>(this.type, this.name, url));
}
private String cleanPath() {
String path = this.path.trim();
if (StringUtils.hasLength(path)) {
if (!path.startsWith("/")) {
path = "/" + path;
}
if (path.endsWith("/")) {
path = path.substring(0, path.length() - 1);
}
}
return path;
}
//......
}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
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<String, FeignClientConfiguration> 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<String, FeignClientConfiguration> getConfig() {
return this.config;
}
public void setConfig(Map<String, FeignClientConfiguration> 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> retryer;
private Class<ErrorDecoder> errorDecoder;
private List<Class<RequestInterceptor>> requestInterceptors;
private Boolean decode404;
private Class<Decoder> decoder;
private Class<Encoder> encoder;
private Class<Contract> 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<Retryer> getRetryer() {
return this.retryer;
}
public void setRetryer(Class<Retryer> retryer) {
this.retryer = retryer;
}
public Class<ErrorDecoder> getErrorDecoder() {
return this.errorDecoder;
}
public void setErrorDecoder(Class<ErrorDecoder> errorDecoder) {
this.errorDecoder = errorDecoder;
}
public List<Class<RequestInterceptor>> getRequestInterceptors() {
return this.requestInterceptors;
}
public void setRequestInterceptors(
List<Class<RequestInterceptor>> requestInterceptors) {
this.requestInterceptors = requestInterceptors;
}
public Boolean getDecode404() {
return this.decode404;
}
public void setDecode404(Boolean decode404) {
this.decode404 = decode404;
}
public Class<Decoder> getDecoder() {
return this.decoder;
}
public void setDecoder(Class<Decoder> decoder) {
this.decoder = decoder;
}
public Class<Encoder> getEncoder() {
return this.encoder;
}
public void setEncoder(Class<Encoder> encoder) {
this.encoder = encoder;
}
public Class<Contract> getContract() {
return this.contract;
}
public void setContract(Class<Contract> 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
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，请继续关注亿速云网站，小编会继续努力为大家带来更多实用的文章！
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