冲动是魔鬼

WLS支持在Global transaction中存在最多一个非XA的Datasource，这就决定了在同一个Tx context下，Datasource.getConnection必须保证总是从ConnectionPool中选出相同的物理连接，不过从JDBC规范来讲，这件事应该是不需要被保证的。

官方声明

http://edocs.beasys.com/wls/docs81/faq/jdbc.html

Q. If an application calls DataSource.getConnection multiple times in the same thread and transaction, will WebLogic Server handle giving me the same connection and transaction?

A. A common scenario might be to have multiple methods that are called within a transaction (begin/commit) that do something like the following:

Context ctx = new InitialContext();
DataSource ds = (javax.sql.DataSource) ctx.lookup("connpoll");
// work using Connection

In this case, all of the work will be done within the transaction and the same underlying JDBC connection will be used as long as the DataSource ds is a tx data source.