使用tomcat和jotm实现的一个JTA的例子
一、目的：在一个程序中，想达到对oracle数据库与sql server2000数据库的操作通过一个事务来管理，一起提交一起回滚，需要用到JTA。参考文档：http://www.blogjava.net/zhanglijun33/archive/2006/09/21/jta.html
二、下面说下我的具体实现：
1、JOTM包：
下载地址：http://jotm.ow2.org/xwiki/bin/view/Main/Download_Releases
我用的是ow2-jotm-dist-2.1.9-bin，由于我使用的是比较新的JOTM版本，所以不需要考虑参考文档中4.1提到的问题。
2、tomcat环境：
(1)版本：5.5.26
(2)commons\lib:把ow2-jotm-dist-2.1.9\lib中的包都放进来。
(3)context.xml:
<Context>
......
<Resource name="jdbc/orcldb"
auth="Container"
type="javax.sql.DataSource"
factory="org.objectweb.jotm.datasource.DataSourceFactory"
driverClassName="oracle.jdbc.driver.OracleDriver"
username="bt_dyw" password="bt_dyw"
url="jdbc:oracle:thin:@localhost:1521:orcl"/>
<Resource name="jdbc/sqldb"
auth="Container"
type="javax.sql.DataSource"
factory="org.objectweb.jotm.datasource.DataSourceFactory"
driverClassName="com.microsoft.jdbc.sqlserver.SQLServerDriver"
username="sa" password="sa"
url="jdbc:microsoft:sqlserver://BJ152:1433;DataBaseName=bt_jszx;SelectMethod=cursor"/>
<Resource name="UserTransaction"
auth="Container"
type="javax.transaction.UserTransaction" />
<Transaction factory="org.objectweb.jotm.UserTransactionFactory"
jotm.timeout="60"/>
......
</Context>
4、web应用中的代码:
index.jsp:
<%@page contentType="text/html;charset=GB2312"%>
<%@page import="java.sql.*"%>
<%@page import="javax.sql.*"%>
<%@page import="javax.naming.*"%>
<%@page import="javax.transaction.UserTransaction"%>
<%
Connection connOracle = null;
Statement stmtOracle = null;
ResultSet rsOracle = null;
Connection connSql = null;
Statement stmtSql = null;
ResultSet rsSql = null;
UserTransaction ut = null;
try {
Context initCtx = new InitialContext();
Context envCtx = (Context) initCtx.lookup("java:comp/env");
DataSource dsOracle = (DataSource) envCtx.lookup("jdbc/orcldb");
DataSource dsSql = (DataSource) envCtx.lookup("jdbc/sqldb");
ut = (UserTransaction)initCtx.lookup("java:comp/UserTransaction");
connOracle = dsOracle.getConnection();
connSql = dsSql.getConnection();
ut.begin();
System.out.println("<<< beginning the transaction >>>");
stmtOracle = connOracle.createStatement(
// ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE
);
rsOracle = stmtOracle.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsOracle.next();
stmtSql = connSql.createStatement(
// ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE
);
rsSql = stmtSql.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsSql.next();
} catch(Exception e) {
e.printStackTrace();
}
%>
<html>
<body>
Original price Oracle:
<%=rsOracle.getString("price")%>
<br />Original price Sql:
<%=rsSql.getString("price")%>
<br />After update Oracle:
<%
PreparedStatement pstmtOracle = connOracle.prepareStatement("update tm_product set price=? where id=1");
pstmtOracle.setInt(1,101);
pstmtOracle.executeUpdate();
rsOracle = stmtOracle.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsOracle.next();
%>
<%=rsOracle.getString("price")%>
<br />After update Sql:
<%
PreparedStatement pstmtSql = connSql.prepareStatement("update tm_product set price=? where id=1");
pstmtSql.setInt(1,101);
pstmtSql.executeUpdate();
rsSql = stmtSql.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsSql.next();
%>
<%=rsSql.getString("price")%>
<%
System.out.println("<<< rolling back the transaction >>>");
ut.rollback();//Or ut.commit();
%>
<br />After Rollback Oracle:
<%
rsOracle = stmtOracle.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsOracle.next();
%>
<%=rsOracle.getString("price")%>
<%connOracle.close();%>
<br />After Rollback Sql:
<%
rsSql = stmtSql.executeQuery("SELECT PRICE FROM TM_PRODUCT WHERE ID=1");
rsSql.next();
%>
<%=rsSql.getString("price")%>
<%connSql.close();%>
</body>
</html> 5、测试用数据的准备
oracle中：
create table tm_product(id number(9) primary key,price number(9));
insert into tm_product values(1,1200);
commit;
sql server2000中:
create table tm_product(id numeric(9) primary key,price numeric(9));
insert into tm_product values(1,1500);
6、异常处理
(1)java.lang.ClassCastException: org.objectweb.jotm.Current
我的应用Lib中的jta.jar冲突，去掉后OK
(2)java.sql.SQLException: Can't start a cloned connection while in manual transaction mode.
参考：http://blog.sina.com.cn/s/blog_4ffb1bf201009ld3.html
7、页面结果展示
Original price Oracle: 1200
Original price Sql: 1500
After update Oracle: 101
After update Sql: 101
After Rollback Oracle: 1200
After Rollback Sql: 1500
ps:
ut的timeout设置：
ut.setTransactionTimeout(3600*5);
页:
[1]