Tomcat是Servlet容器,但它也提供了一个JNDI InitialContext实现,因此用户可以像在J2EE应用程序服务器中一样在Tomcat中使用JNDI查找JDBC数据源。不过在事务处理方面,Tomcat本身并不支持JTA(Java Transaction API),所以需要借助其他的方案。JOTM(Java Open Transaction Manager)是ObjectWeb的一个开源JTA实现,它本身也是开源应用程序服务器JOnAS(Java Open Application Server)的一部分,为其提供JTA支持和分布式事务管理。JOTM同样可以为Tomcat提供JTA支持,以下将对相关的配置进行简单说明,使用的相应版本为:
ut.begin();
System.out.println("<<< beginning the transaction >>>");
stmt = conn.createStatement(
// ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE
);
rs = stmt.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rs.next();
} catch(Exception e) {e.printStackTrace();}
%>
<html>
<body>
Original price:
<%=rs.getString("price")%>
<br>After update:
<%
PreparedStatement pstmt = conn.prepareStatement("update tm_product set price=? where id=1");
pstmt.setInt(1,101);
pstmt.executeUpdate();
rs = stmt.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rs.next();
%>
<%=rs.getString("price")%>
<br>After Rollback:
<%
System.out.println("<<< rolling back the transaction >>>");
ut.rollback();//Or ut.commit();
rs = stmt.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rs.next();
%>
<%=rs.getString("price")%>
<%conn.close();%>
</body>
</html>
6. 参考
How to use JDBC and transactions in Tomcat with JOTM
How to use JDBC and transactions in Tomcat with JOTM(For Tomcat 5.5.x)
UserTransaction, JOTM and Tomcat 5.5.x