RocketMQTransactionAnnotationProcessor的原理和用法
本篇内容介绍了“RocketMQTransactionAnnotationProcessor的原理和用法”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
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本文主要研究一下RocketMQTransactionAnnotationProcessor
RocketMQTransactionAnnotationProcessor
rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/config/RocketMQTransactionAnnotationProcessor.java
public class RocketMQTransactionAnnotationProcessor
implements BeanPostProcessor, Ordered, ApplicationContextAware {
private final static Logger log = LoggerFactory.getLogger(RocketMQTransactionAnnotationProcessor.class);
private ApplicationContext applicationContext;
private final Set> nonProcessedClasses =
Collections.newSetFromMap(new ConcurrentHashMap, Boolean>(64));
private TransactionHandlerRegistry transactionHandlerRegistry;
public RocketMQTransactionAnnotationProcessor(TransactionHandlerRegistry transactionHandlerRegistry) {
this.transactionHandlerRegistry = transactionHandlerRegistry;
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext = applicationContext;
}
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if (!this.nonProcessedClasses.contains(bean.getClass())) {
Class targetClass = AopUtils.getTargetClass(bean);
RocketMQTransactionListener listener = AnnotationUtils.findAnnotation(targetClass, RocketMQTransactionListener.class);
this.nonProcessedClasses.add(bean.getClass());
if (listener == null) { // for quick search
log.trace("No @RocketMQTransactionListener annotations found on bean type: {}", bean.getClass());
} else {
try {
processTransactionListenerAnnotation(listener, bean);
} catch (MQClientException e) {
log.error("Failed to process annotation " + listener, e);
throw new BeanCreationException("Failed to process annotation " + listener, e);
}
}
}
return bean;
}
private void processTransactionListenerAnnotation(RocketMQTransactionListener listener, Object bean)
throws MQClientException {
if (transactionHandlerRegistry == null) {
throw new MQClientException("Bad usage of @RocketMQTransactionListener, " +
"the class must work with RocketMQTemplate", null);
}
if (!RocketMQLocalTransactionListener.class.isAssignableFrom(bean.getClass())) {
throw new MQClientException("Bad usage of @RocketMQTransactionListener, " +
"the class must implement interface RocketMQLocalTransactionListener",
null);
}
TransactionHandler transactionHandler = new TransactionHandler();
transactionHandler.setBeanFactory(this.applicationContext.getAutowireCapableBeanFactory());
transactionHandler.setName(listener.txProducerGroup());
transactionHandler.setBeanName(bean.getClass().getName());
transactionHandler.setListener((RocketMQLocalTransactionListener) bean);
transactionHandler.setCheckExecutor(listener.corePoolSize(), listener.maximumPoolSize(),
listener.keepAliveTime(), listener.blockingQueueSize());
RPCHook rpcHook = RocketMQUtil.getRPCHookByAkSk(applicationContext.getEnvironment(),
listener.accessKey(), listener.secretKey());
if (Objects.nonNull(rpcHook)) {
transactionHandler.setRpcHook(rpcHook);
} else {
log.debug("Access-key or secret-key not configure in " + listener + ".");
}
transactionHandlerRegistry.registerTransactionHandler(transactionHandler);
}
@Override
public int getOrder() {
return LOWEST_PRECEDENCE;
}
} RocketMQTransactionAnnotationProcessor实现了BeanPostProcessor, Ordered, ApplicationContextAware接口
postProcessAfterInitialization方法会查找标记有RocketMQTransactionListener注解的bean，然后执行processTransactionListenerAnnotation方法
processTransactionListenerAnnotation方法会创建transactionHandler，然后执行transactionHandlerRegistry.registerTransactionHandler进行注册
TransactionHandler
rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/config/TransactionHandler.java
class TransactionHandler {
private String name;
private String beanName;
private RocketMQLocalTransactionListener bean;
private BeanFactory beanFactory;
private ThreadPoolExecutor checkExecutor;
private RPCHook rpcHook;
public String getBeanName() {
return beanName;
}
public void setBeanName(String beanName) {
this.beanName = beanName;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public RPCHook getRpcHook() {
return rpcHook;
}
public void setRpcHook(RPCHook rpcHook) {
this.rpcHook = rpcHook;
}
public BeanFactory getBeanFactory() {
return beanFactory;
}
public void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}
public void setListener(RocketMQLocalTransactionListener listener) {
this.bean = listener;
}
public RocketMQLocalTransactionListener getListener() {
return this.bean;
}
public void setCheckExecutor(int corePoolSize, int maxPoolSize, long keepAliveTime, int blockingQueueSize) {
this.checkExecutor = new ThreadPoolExecutor(corePoolSize, maxPoolSize,
keepAliveTime, TimeUnit.MILLISECONDS,
new LinkedBlockingDeque<>(blockingQueueSize));
}
public ThreadPoolExecutor getCheckExecutor() {
return checkExecutor;
}
}TransactionHandler包含了name、beanName、bean、beanFactory、checkExecutor、rpcHook属性
TransactionHandlerRegistry
rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/config/TransactionHandlerRegistry.java
public class TransactionHandlerRegistry implements DisposableBean {
private RocketMQTemplate rocketMQTemplate;
private final Set listenerContainers = new ConcurrentSet<>();
public TransactionHandlerRegistry(RocketMQTemplate template) {
this.rocketMQTemplate = template;
}
@Override
public void destroy() throws Exception {
listenerContainers.clear();
}
public void registerTransactionHandler(TransactionHandler handler) throws MQClientException {
if (listenerContainers.contains(handler.getName())) {
throw new MQClientException(-1,
String
.format("The transaction name [%s] has been defined in TransactionListener [%s]", handler.getName(),
handler.getBeanName()));
}
listenerContainers.add(handler.getName());
rocketMQTemplate.createAndStartTransactionMQProducer(handler.getName(), handler.getListener(), handler.getCheckExecutor(), handler.getRpcHook());
}
} TransactionHandlerRegistry实现了DisposableBean接口，其clear方法直接清空listenerContainers；registerTransactionHandler方法会往listenerContainers添加该handler的name，然后执行rocketMQTemplate.createAndStartTransactionMQProducer来创建并启动TransactionMQProducer
小结
RocketMQTransactionAnnotationProcessor实现了BeanPostProcessor, Ordered, ApplicationContextAware接口
postProcessAfterInitialization方法会查找标记有RocketMQTransactionListener注解的bean，然后执行processTransactionListenerAnnotation方法
processTransactionListenerAnnotation方法会创建transactionHandler，然后执行transactionHandlerRegistry.registerTransactionHandler进行注册
“RocketMQTransactionAnnotationProcessor的原理和用法”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注创新互联网站，小编将为大家输出更多高质量的实用文章！
文章题目：RocketMQTransactionAnnotationProcessor的原理和用法
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