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2022-12-24发表Java / Spring / Spring Cloud Alibaba11 分钟读完 (大约1633个字)

Spring Cloud Alibaba Seata 源码分析服务端（TC）源码解读

服务端表解释

我们的Seata服务端在应用的时候需要准备三张表，那么这三张表分别代表的意思就是

branch_table 分支事务表
global_table 全局事务表
lock_table 全局锁表

客户端请求服务端以后，我们就需要把对应的全局事务包括分支事务和全局锁全部存放到这里。

![image.png](spring-cloud-alibaba-seata-source-code-analysis-server (-tc)-source-code-interpretation/a1cca08a47184ea5b4d1a2ba1cb12b5e.png)

2022-12-19发表Java / Spring / Spring Cloud Alibaba10 分钟读完 (大约1524个字)

Spring Cloud Alibaba Seata 2PC 核心源码解读

2PC提交源码流程

GlobalTransactionalInterceptor全局事务拦截器，一旦执行拦截器，就会进入到其中的invoke方法，在这其中会做一些@GlobalTransactional注解的判断，如果有注解以后，会执行全局事务和全局锁，那么在执行全局事务的时候会调用handleGlobalTransaction全局事务处理器，这里主要是获取事务信息

Object handleGlobalTransaction(final MethodInvocation methodInvocation,
                               final GlobalTransactional globalTrxAnno) throws Throwable {
    boolean succeed = true;
    try {
        return transactionalTemplate.execute(new TransactionalExecutor() {
            @Override
            public Object execute() throws Throwable {
                return methodInvocation.proceed();
            }

            // 获取事务名称，默认获取方法名
            public String name() {
                String name = globalTrxAnno.name();
                if (!StringUtils.isNullOrEmpty(name)) {
                    return name;
                }
                return formatMethod(methodInvocation.getMethod());
            }

            /**
                 * 解析GlobalTransactional注解属性，封装为对象
                 * @return
                 */
            @Override
            public TransactionInfo getTransactionInfo() {
                // reset the value of timeout
                // 获取超时时间，默认60秒
                int timeout = globalTrxAnno.timeoutMills();
                if (timeout <= 0 || timeout == DEFAULT_GLOBAL_TRANSACTION_TIMEOUT) {
                    timeout = defaultGlobalTransactionTimeout;
                }

                // 构建事务信息对象
                TransactionInfo transactionInfo = new TransactionInfo();
                transactionInfo.setTimeOut(timeout);// 超时时间
                transactionInfo.setName(name()); // 事务名称
                transactionInfo.setPropagation(globalTrxAnno.propagation());// 事务传播
                transactionInfo.setLockRetryInternal(globalTrxAnno.lockRetryInternal());// 校验或占用全局锁重试间隔
                transactionInfo.setLockRetryTimes(globalTrxAnno.lockRetryTimes());// 校验或占用全局锁重试次数
                Set<RollbackRule> rollbackRules = new LinkedHashSet<>();
                // 其他构建信息
                for (Class<?> rbRule : globalTrxAnno.rollbackFor()) {
                    rollbackRules.add(new RollbackRule(rbRule));
                }
                for (String rbRule : globalTrxAnno.rollbackForClassName()) {
                    rollbackRules.add(new RollbackRule(rbRule));
                }
                for (Class<?> rbRule : globalTrxAnno.noRollbackFor()) {
                    rollbackRules.add(new NoRollbackRule(rbRule));
                }
                for (String rbRule : globalTrxAnno.noRollbackForClassName()) {
                    rollbackRules.add(new NoRollbackRule(rbRule));
                }
                transactionInfo.setRollbackRules(rollbackRules);
                return transactionInfo;
            }
        });
    } catch (TransactionalExecutor.ExecutionException e) {
        // 执行异常
        TransactionalExecutor.Code code = e.getCode();
        switch (code) {
            case RollbackDone:
                throw e.getOriginalException();
            case BeginFailure:
                succeed = false;
                failureHandler.onBeginFailure(e.getTransaction(), e.getCause());
                throw e.getCause();
            case CommitFailure:
                succeed = false;
                failureHandler.onCommitFailure(e.getTransaction(), e.getCause());
                throw e.getCause();
            case RollbackFailure:
                failureHandler.onRollbackFailure(e.getTransaction(), e.getOriginalException());
                throw e.getOriginalException();
            case RollbackRetrying:
                failureHandler.onRollbackRetrying(e.getTransaction(), e.getOriginalException());
                throw e.getOriginalException();
            default:
                throw new ShouldNeverHappenException(String.format("Unknown TransactionalExecutor.Code: %s", code));
        }
    } finally {
        if (degradeCheck) {
            EVENT_BUS.post(new DegradeCheckEvent(succeed));
        }
    }
}