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Dubbo源码解析之ReferenceBean_referencebean.get() failed to check the status of

作者：笔触狂放9 | 2024-02-29 13:32:13

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referencebean.get() failed to check the status of the service

一个dubbo服务需要 api、provider、consumer构成

api提供接口供provider和consumer引用

1、接口的实现类需要用

org.apache.dubbo.config.annotation.Service包的@Service注解
  1. @Service(version = "1.0.1")
  2. public class ExampleImpl implements ExampleService {
  3.  
  4.     @Override
  5.     public String sayHello() {
  6.         return "new springboot dubbo project";
  7.     }
  8. }

区别于Spring的@Service注解

 

2、接口的引用方需要

org.apache.dubbo.config.annotation.Reference包的@Reference

形如：

  1. //本地服务
  2. @Autowired
  3. LocalService localService;
  4. //dubbo服务
  5. @Reference
  6. ExampleService exampleService;

 

可能使用起来会有同学觉得不方便，无论是实现还是引用可不可以只用Spring的注解呢，这时需要ReferenceBean出马了

使用方法，由provider新建moduel-client供consumer调用，client引用api

  1. @Bean
  2. public ReferenceBean<PLConfigService> configServiceReferenceBean(){
  3.     ReferenceBean<PLConfigService> referenceBean = new ReferenceBean<>();
  4.     referenceBean.setInterface(PLConfigService.class);
  5.     referenceBean.setCheck(false);
  6.     return referenceBean;
  7. }
public class ReferenceBean<T> extends ReferenceConfig<T> implements FactoryBean, ApplicationContextAware, InitializingBean, DisposableBean {...}

ReferenceBean实现了InitializingBean接口的afterPropertiesSet()，所以Spring会在初始化该类的属性后调用afterPropertiesSet方法

入口：

  1. public void afterPropertiesSet() throws Exception {
  2.     //加载ConsumerConfig
  3.     if (getConsumer() == null) {
  4.         Map<String, ConsumerConfig> consumerConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ConsumerConfig.class, false, false);
  5.         if (consumerConfigMap != null && consumerConfigMap.size() > 0) {
  6.             ConsumerConfig consumerConfig = null;
  7.             for (ConsumerConfig config : consumerConfigMap.values()) {
  8.                 if (config.isDefault() == null || config.isDefault().booleanValue()) {
  9.                     if (consumerConfig != null) {
  10.                         throw new IllegalStateException("Duplicate consumer configs: " + consumerConfig + " and " + config);
  11.                     }
  12.                     consumerConfig = config;
  13.                 }
  14.             }
  15.             if (consumerConfig != null) {
  16.                 setConsumer(consumerConfig);
  17.             }
  18.         }
  19.     }
  20.     //加载应用上下文
  21.     if (getApplication() == null
  22.             && (getConsumer() == null || getConsumer().getApplication() == null)) {
  23.         Map<String, ApplicationConfig> applicationConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ApplicationConfig.class, false, false);
  24.         if (applicationConfigMap != null && applicationConfigMap.size() > 0) {
  25.             ApplicationConfig applicationConfig = null;
  26.             for (ApplicationConfig config : applicationConfigMap.values()) {
  27.                 if (config.isDefault() == null || config.isDefault().booleanValue()) {
  28.                     if (applicationConfig != null) {
  29.                         throw new IllegalStateException("Duplicate application configs: " + applicationConfig + " and " + config);
  30.                     }
  31.                     applicationConfig = config;
  32.                 }
  33.             }
  34.             if (applicationConfig != null) {
  35.                 setApplication(applicationConfig);
  36.             }
  37.         }
  38.     }
  39.     //加载ModuleConfig
  40.     if (getModule() == null
  41.             && (getConsumer() == null || getConsumer().getModule() == null)) {
  42.         Map<String, ModuleConfig> moduleConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, ModuleConfig.class, false, false);
  43.         if (moduleConfigMap != null && moduleConfigMap.size() > 0) {
  44.             ModuleConfig moduleConfig = null;
  45.             for (ModuleConfig config : moduleConfigMap.values()) {
  46.                 if (config.isDefault() == null || config.isDefault().booleanValue()) {
  47.                     if (moduleConfig != null) {
  48.                         throw new IllegalStateException("Duplicate module configs: " + moduleConfig + " and " + config);
  49.                     }
  50.                     moduleConfig = config;
  51.                 }
  52.             }
  53.             if (moduleConfig != null) {
  54.                 setModule(moduleConfig);
  55.             }
  56.         }
  57.     }
  58.     //加载RegistryConfig
  59.     if ((getRegistries() == null || getRegistries().size() == 0)
  60.             && (getConsumer() == null || getConsumer().getRegistries() == null || getConsumer().getRegistries().size() == 0)
  61.             && (getApplication() == null || getApplication().getRegistries() == null || getApplication().getRegistries().size() == 0)) {
  62.         Map<String, RegistryConfig> registryConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, RegistryConfig.class, false, false);
  63.         if (registryConfigMap != null && registryConfigMap.size() > 0) {
  64.             List<RegistryConfig> registryConfigs = new ArrayList<RegistryConfig>();
  65.             for (RegistryConfig config : registryConfigMap.values()) {
  66.                 if (config.isDefault() == null || config.isDefault().booleanValue()) {
  67.                     registryConfigs.add(config);
  68.                 }
  69.             }
  70.             if (registryConfigs != null && registryConfigs.size() > 0) {
  71.                 super.setRegistries(registryConfigs);
  72.             }
  73.         }
  74.     }
  75.     //加载MonitorConfig
  76.     if (getMonitor() == null
  77.             && (getConsumer() == null || getConsumer().getMonitor() == null)
  78.             && (getApplication() == null || getApplication().getMonitor() == null)) {
  79.         Map<String, MonitorConfig> monitorConfigMap = applicationContext == null ? null : BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, MonitorConfig.class, false, false);
  80.         if (monitorConfigMap != null && monitorConfigMap.size() > 0) {
  81.             MonitorConfig monitorConfig = null;
  82.             for (MonitorConfig config : monitorConfigMap.values()) {
  83.                 if (config.isDefault() == null || config.isDefault().booleanValue()) {
  84.                     if (monitorConfig != null) {
  85.                         throw new IllegalStateException("Duplicate monitor configs: " + monitorConfig + " and " + config);
  86.                     }
  87.                     monitorConfig = config;
  88.                 }
  89.             }
  90.             if (monitorConfig != null) {
  91.                 setMonitor(monitorConfig);
  92.             }
  93.         }
  94.     }
  95.     //以上config都在DubboAutoConfiguration中加载进了Spring容器中
  96.     Boolean b = isInit();
  97.     if (b == null && getConsumer() != null) {
  98.         b = getConsumer().isInit();
  99.     }
  100.     if (b != null && b.booleanValue()) {
  101.         //重点 这一步会将之前set的interface加载进来
  102.         getObject();
  103.     }
  104. }
  1. public Object getObject() throws Exception {
  2.     return get();
  3. }

get()是父类ReferenceConfig<T>的方法,T为传入的接口的类型

  1. // 接口代理类引用
  2. private transient volatile T ref;
  1. public synchronized T get() {
  2.     if (destroyed) {
  3.         throw new IllegalStateException("Already destroyed!");
  4.     }
  5.     if (ref == null) {
  6.         //初始化
  7.         init();
  8.     }
  9.     return ref;
  10. }

我们setInterface时

  1. public void setInterface(Class<?> interfaceClass) {
  2.     if (interfaceClass != null && !interfaceClass.isInterface()) {
  3.         throw new IllegalStateException("The interface class " + interfaceClass + " is not a interface!");
  4.     }
  5.     this.interfaceClass = interfaceClass;
  6.     setInterface(interfaceClass == null ? (String) null : interfaceClass.getName());
  7. }
  8.  
  9. public void setInterface(String interfaceName) {
  10.     this.interfaceName = interfaceName;
  11.     if (id == null || id.length() == 0) {
  12.         id = interfaceName;
  13.     }
  14. }
  1. private void init() {
  2. //...省略N行
  3. //
  4. checkStubAndMock(interfaceClass);
  5. //...
  6. ref = createProxy(map);
  7. }
  1. private T createProxy(Map<String, String> map) {
  2.     URL tmpUrl = new URL("temp", "localhost", 0, map);
  3.     final boolean isJvmRefer;
  4.     if (isInjvm() == null) {
  5.         if (url != null && url.length() > 0) { //指定URL的情况下，不做本地引用
  6.             isJvmRefer = false;
  7.         } else if (InjvmProtocol.getInjvmProtocol().isInjvmRefer(tmpUrl)) {
  8.             //默认情况下如果本地有服务暴露，则引用本地服务.
  9.             isJvmRefer = true;
  10.         } else {
  11.             isJvmRefer = false;
  12.         }
  13.     } else {
  14.         isJvmRefer = isInjvm().booleanValue();
  15.     }
  16.  
  17.     if (isJvmRefer) {
  18.         URL url = new URL(Constants.LOCAL_PROTOCOL, NetUtils.LOCALHOST, 0, interfaceClass.getName()).addParameters(map);
  19.         invoker = refprotocol.refer(interfaceClass, url);
  20.         if (logger.isInfoEnabled()) {
  21.             logger.info("Using injvm service " + interfaceClass.getName());
  22.         }
  23.     } else {
  24.         if (url != null && url.length() > 0) { // 用户指定URL，指定的URL可能是对点对直连地址，也可能是注册中心URL
  25.             String[] us = Constants.SEMICOLON_SPLIT_PATTERN.split(url);
  26.             if (us != null && us.length > 0) {
  27.                 for (String u : us) {
  28.                     URL url = URL.valueOf(u);
  29.                     if (url.getPath() == null || url.getPath().length() == 0) {
  30.                         url = url.setPath(interfaceName);
  31.                     }
  32.                     if (Constants.REGISTRY_PROTOCOL.equals(url.getProtocol())) {
  33.                         urls.add(url.addParameterAndEncoded(Constants.REFER_KEY, StringUtils.toQueryString(map)));
  34.                     } else {
  35.                         urls.add(ClusterUtils.mergeUrl(url, map));
  36.                     }
  37.                 }
  38.             }
  39.         } else { // 通过注册中心配置拼装URL
  40.             List<URL> us = loadRegistries(false);
  41.             if (us != null && us.size() > 0) {
  42.                 for (URL u : us) {
  43.                     URL monitorUrl = loadMonitor(u);
  44.                     if (monitorUrl != null) {
  45.                         map.put(Constants.MONITOR_KEY, URL.encode(monitorUrl.toFullString()));
  46.                     }
  47.                     urls.add(u.addParameterAndEncoded(Constants.REFER_KEY, StringUtils.toQueryString(map)));
  48.                 }
  49.             }
  50.             if (urls == null || urls.size() == 0) {
  51.                 throw new IllegalStateException("No such any registry to reference " + interfaceName + " on the consumer " + NetUtils.getLocalHost() + " use dubbo version " + Version.getVersion() + ", please config <dubbo:registry address=\"...\" /> to your spring config.");
  52.             }
  53.         }
  54.  
  55.         if (urls.size() == 1) {
  56.             invoker = refprotocol.refer(interfaceClass, urls.get(0));
  57.         } else {
  58.             List<Invoker<?>> invokers = new ArrayList<Invoker<?>>();
  59.             URL registryURL = null;
  60.             for (URL url : urls) {
  61.                 invokers.add(refprotocol.refer(interfaceClass, url));
  62.                 if (Constants.REGISTRY_PROTOCOL.equals(url.getProtocol())) {
  63.                     registryURL = url; // 用了最后一个registry url
  64.                 }
  65.             }
  66.             if (registryURL != null) { // 有 注册中心协议的URL
  67.                 // 对有注册中心的Cluster 只用 AvailableCluster
  68.                 URL u = registryURL.addParameter(Constants.CLUSTER_KEY, AvailableCluster.NAME);
  69.                 invoker = cluster.join(new StaticDirectory(u, invokers));
  70.             } else { // 不是 注册中心的URL
  71.                 invoker = cluster.join(new StaticDirectory(invokers));
  72.             }
  73.         }
  74.     }
  75.  
  76.     Boolean c = check;
  77.     if (c == null && consumer != null) {
  78.         c = consumer.isCheck();
  79.     }
  80.     if (c == null) {
  81.         c = true; // default true
  82.     }
  83.     if (c && !invoker.isAvailable()) {
  84.         throw new IllegalStateException("Failed to check the status of the service " + interfaceName + ". No provider available for the service " + (group == null ? "" : group + "/") + interfaceName + (version == null ? "" : ":" + version) + " from the url " + invoker.getUrl() + " to the consumer " + NetUtils.getLocalHost() + " use dubbo version " + Version.getVersion());
  85.     }
  86.     if (logger.isInfoEnabled()) {
  87.         logger.info("Refer dubbo service " + interfaceClass.getName() + " from url " + invoker.getUrl());
  88.     }
  89.     // 创建服务代理
  90.     return (T) proxyFactory.getProxy(invoker);
  91. }

 

 

 

 

 
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