如何配置jboss数据源为分布式事务的形式

我新建了一个mysql-xa-ds.xml文件放在deploy目录下

 <?xml version="1.0" encoding="UTF-8"?>

<datasources>


    <xa-datasource>
        <jndi-name>DataSource</jndi-name>
        <track-connection-by-tx>true</track-connection-by-tx>
        <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class>
        <new-connection-sql>set autocommit=1</new-connection-sql>
        <no-tx-separate-pools>true</no-tx-separate-pools>
        <xa-datasource-property name="Url">jdbc:mysql://127.0.0.1:3306/register?autoReconnect=true</xa-datasource-property>
        <xa-datasource-property name="User">root</xa-datasource-property>
        <xa-datasource-property name="Password">root</xa-datasource-property>

        <transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>

        <exception-sorter-class-name>
            org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter
        </exception-sorter-class-name>
        <type-mapping>mySQL</type-mapping>

        <!--pooling parameters--> 
        <min-pool-size>5</min-pool-size>
        <max-pool-size>100</max-pool-size>
        <blocking-timeout-millis>5000</blocking-timeout-millis>
        <idle-timeout-minutes>15</idle-timeout-minutes>
    </xa-datasource>
</datasources>

jboss控制台上也输出了绑定DataSource成功 但是当我用Context.lookup("DataSource")查找时却提示not bound
这是怎么回事

是需要额外的驱动吗？