public void noTransaction() {
        Connection connection = null;
        String sql = "update account set balance=balance-100 where id=1";
        String sql2 = "update account set balance=balance+100 where id=2";
        //創(chuàng)建PreparedStatement對象
        PreparedStatement preparedStatement = null;
        try {
            connection = JDBCUtils.getConnection();// 獲取數(shù)據(jù)庫連接
            connection.setAutoCommit(false);//事務開始
            preparedStatement = connection.prepareStatement(sql);
            preparedStatement.executeUpdate();//執(zhí)行第一個sql
            preparedStatement = connection.prepareStatement(sql2);
            preparedStatement.executeUpdate();//執(zhí)行sql2
            //提交事務
            connection.commit();
        } catch (SQLException e) {
            //進行事務回滾，默認回滾到事務開始的地方
            try {
                connection.rollback();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
            e.printStackTrace();
        } finally {
            //關閉流
            JDBCUtils.close(null, preparedStatement, connection);
        }
    }

@Override
@Nullable
public <T> T execute(TransactionCallback<T> action) throws TransactionException {
   Assert.state(this.transactionManager != null, "No PlatformTransactionManager set");

   if (this.transactionManager instanceof CallbackPreferringPlatformTransactionManager) {
      return ((CallbackPreferringPlatformTransactionManager) this.transactionManager).execute(this, action);
   }
   else {
       //獲取事務 
      TransactionStatus status = this.transactionManager.getTransaction(this);
      T result;
      try {
          //執(zhí)行SQL語句內(nèi)容
         result = action.doInTransaction(status);
      }
      catch (RuntimeException | Error ex) {
         //異?；貪L
         rollbackOnException(status, ex);
         throw ex;
      }
      catch (Throwable ex) {
         // 異?；貪L
         rollbackOnException(status, ex);
         throw new UndeclaredThrowableException(ex, "TransactionCallback threw undeclared checked exception");
      }
       //提交事務
      this.transactionManager.commit(status);
      return result;
   }
}

@Override
public boolean isCandidateClass(Class<?> targetClass) {
   for (TransactionAnnotationParser parser : this.annotationParsers) {
      if (parser.isCandidateClass(targetClass)) {
         return true;
      }
   }
   return false;
}

@Override
public boolean isCandidateClass(Class<?> targetClass) {
   return AnnotationUtils.isCandidateClass(targetClass, Transactional.class);
}

@Override
@Nullable
public Object invoke(MethodInvocation invocation) throws Throwable {
    // 判斷執(zhí)行的方法屬于哪個類
   Class<?> targetClass = (invocation.getThis() != null ? AopUtils.getTargetClass(invocation.getThis()) : null);
    //再調(diào)用事務進行執(zhí)行
   return invokeWithinTransaction(invocation.getMethod(), targetClass, new CoroutinesInvocationCallback() {
      @Override
      @Nullable
      public Object proceedWithInvocation() throws Throwable {
         return invocation.proceed();
      }
      @Override
      public Object getTarget() {
         return invocation.getThis();
      }
      @Override
      public Object[] getArguments() {
         return invocation.getArguments();
      }
   });
}

@Nullable
protected Object invokeWithinTransaction(Method method, @Nullable Class<?> targetClass,
      final InvocationCallback invocation) throws Throwable {
   TransactionAttributeSource tas = getTransactionAttributeSource();
   final TransactionAttribute txAttr = (tas != null ? tas.getTransactionAttribute(method, targetClass) : null);
   final TransactionManager tm = determineTransactionManager(txAttr);
	.......
        
   PlatformTransactionManager ptm = asPlatformTransactionManager(tm);
   final String joinpointIdentification = methodIdentification(method, targetClass, txAttr);
   if (txAttr == null || !(ptm instanceof CallbackPreferringPlatformTransactionManager)) {
      // 創(chuàng)建事務
      TransactionInfo txInfo = createTransactionIfNecessary(ptm, txAttr, joinpointIdentification);
      Object retVal;
      try {
         // 執(zhí)行方法
         retVal = invocation.proceedWithInvocation();
      } catch (Throwable ex) {
         // 回滾處理 + 拋出異常終止執(zhí)行
         completeTransactionAfterThrowing(txInfo, ex);
         throw ex;
      } finally {
         cleanupTransactionInfo(txInfo);
      }
		// 正常執(zhí)行了事務，此時再執(zhí)行回調(diào)
      if (retVal != null && vavrPresent && VavrDelegate.isVavrTry(retVal)) {
         TransactionStatus status = txInfo.getTransactionStatus();
         if (status != null && txAttr != null) {
            retVal = VavrDelegate.evaluateTryFailure(retVal, txAttr, status);
         }
      }
		// 提交事務
      commitTransactionAfterReturning(txInfo);
      return retVal;
   }
}