文章类型网站,长沙网站制作公司推荐,做领域细分行业需要建网站吗,制作一个网站需要注意什么Seata源码剖析-源码入口
Seata客户端启动
首先一个Seata的客户端启动一般分为几个流程#xff1a;
自动加载各种Bean及配置信息初始化TM初始化RM#xff08;具体服务#xff09;初始化分布式事务客户端完成#xff0c;代理数据源连接TC#xff08;Seata服务端#xff…Seata源码剖析-源码入口
Seata客户端启动
首先一个Seata的客户端启动一般分为几个流程
自动加载各种Bean及配置信息初始化TM初始化RM具体服务初始化分布式事务客户端完成代理数据源连接TCSeata服务端注册RM注册TM开启全局事务
在这个其中就会涉及到几个核心的类型首先我们需要来看配置类型GlobalTransactionAutoConfiguration
所以我们直接通过官方案例引入的Seata包找到SpringBoot项目在启动的时候自动扫描加载类型的spring.factories然后找到GlobalTransactionAutoConfigurationSeata自动配置类
全局事务扫描类源码
这个类型的核心点就是加载配置注入相关的Bean
/*** seata自动配置类*/
Configuration
EnableConfigurationProperties(SeataProperties.class)
public class GlobalTransactionAutoConfiguration {private final ApplicationContext applicationContext;private final SeataProperties seataProperties;public GlobalTransactionAutoConfiguration(ApplicationContext applicationContext,SeataProperties seataProperties) {this.applicationContext applicationContext;this.seataProperties seataProperties;}// 注入全局事务扫描器Beanpublic GlobalTransactionScanner globalTransactionScanner() {String applicationName applicationContext.getEnvironment().getProperty(spring.application.name);String txServiceGroup seataProperties.getTxServiceGroup();if (StringUtils.isEmpty(txServiceGroup)) {txServiceGroup applicationName -fescar-service-group;seataProperties.setTxServiceGroup(txServiceGroup);}// 构建全局扫描器传入参数应用名、事务分组名失败处理器return new GlobalTransactionScanner(applicationName, txServiceGroup);}
}
GlobalTransactionScanner全局事务扫描器
在这其中我们要关心的是GlobalTransactionScanner这个类型这个类型扫描GlobalTransactional注解并对代理方法进行拦截增强事务的功能。 这里给大家展示了当前GlobalTransactionScanner的类关系图其中我们现在继承了Aop的AbstractAutoProxyCreator类型在这其中有一个重点方法其实这个方法就是判断Bean对象是否需要代理是否需要增强
protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {if (beanName ! null this.targetSourcedBeans.contains(beanName)) {return bean;}if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {return bean;}if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {this.advisedBeans.put(cacheKey, Boolean.FALSE);return bean;}// Create proxy if we have advice.Object[] specificInterceptors getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);if (specificInterceptors ! DO_NOT_PROXY) {this.advisedBeans.put(cacheKey, Boolean.TRUE);Object proxy createProxy(bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));this.proxyTypes.put(cacheKey, proxy.getClass());return proxy;}this.advisedBeans.put(cacheKey, Boolean.FALSE);return bean;
}当然这是父类提供的方法那子类继承之后重写此方法完成了定制化的效果定义不同的代理对象
Override
protected Object wrapIfNecessary奈色色瑞(Object bean, String beanName, Object cacheKey) {try {// 加锁防止并发synchronized (PROXYED_SET) {if (PROXYED_SET.contains(beanName)) {return bean;}interceptor null;//check TCC proxy// 检查是否是TCC模式if (TCCBeanParserUtils.isTccAutoProxy(bean, beanName, applicationContext)) {//TCC interceptor, proxy bean of sofa:reference/dubbo:reference, and LocalTCC// 如果是添加TCC拦截器interceptor new TccActionInterceptor(TCCBeanParserUtils.getRemotingDesc(beanName));ConfigurationCache.addConfigListener(ConfigurationKeys.DISABLE_GLOBAL_TRANSACTION,(ConfigurationChangeListener)interceptor);} else {// 不是TCC模式Class? serviceInterface SpringProxyUtils.findTargetClass(bean);Class?[] interfacesIfJdk SpringProxyUtils.findInterfaces(bean);// 判断是否有相关事务注解如果没有就不代理if (!existsAnnotation(new Class[]{serviceInterface}) !existsAnnotation(interfacesIfJdk)) {return bean;}// 当发现存在全局事务注解标注的Bean添加拦截器if (globalTransactionalInterceptor null) {// 添加拦截器globalTransactionalInterceptor new GlobalTransactionalInterceptor(failureHandlerHook);ConfigurationCache.addConfigListener(ConfigurationKeys.DISABLE_GLOBAL_TRANSACTION,(ConfigurationChangeListener)globalTransactionalInterceptor);}interceptor globalTransactionalInterceptor;}LOGGER.info(Bean[{}] with name [{}] would use interceptor [{}], bean.getClass().getName(), beanName, interceptor.getClass().getName());// 检查是否是代理对象if (!AopUtils.isAopProxy(bean)) {// 不是调用Spring代理父级bean super.wrapIfNecessary(bean, beanName, cacheKey);} else {// 已经是代理对象反射获取代理类中的已经存在的拦截器组合然后添加到该集合当中AdvisedSupport advised SpringProxyUtils.getAdvisedSupport(bean);Advisor[] advisor buildAdvisors(beanName, getAdvicesAndAdvisorsForBean(null, null, null));for (Advisor avr : advisor) {advised.addAdvisor(0, avr);}}// 将Bean添加到Set中PROXYED_SET.add(beanName);return bean;}} catch (Exception exx) {throw new RuntimeException(exx);}
}
