有关ibatis求助

Question

请哪位高手看一下，错在哪里了
public void updateChannel(Channel c) {
try {
session.update(Channel.class.getName()+".updateChannel", c);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
} finally{
session.close();
}
}
配置文件 <update id="updateChannel" parameterType="Channel" >
update t_channel set name=#{name},description=#{description} where id=#{id}
</update>junit测试
@Test
public void testUpdateChannel() {
Channel c = channeldao.getChannelById(11);
c.setName("updatechannel");
channeldao.updateChannel(c);
}出现的错误--------------------------------------------------
org.apache.ibatis.exceptions.PersistenceException: 
### Error updating database.  Cause: org.apache.ibatis.executor.ExecutorException: Executor was closed.
### The error may exist in com/test/cms/backmanager/DAO/implement/Channel.xml
### The error may involve com.test.cms.model.Channel.updateChannel
### The error occurred while executing an update
### Cause: org.apache.ibatis.executor.ExecutorException: Executor was closed.
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8)
at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:123)
at com.test.cms.backmanager.DAO.implement.ChannelDaoForMybatisImpl.updateChannel(ChannelDaoForMybatisImpl.java:89)
at com.test.cms.backmanager.DAO.ChannelDAOTest.testUpdateChannel(ChannelDAOTest.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:73)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:46)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:180)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:41)
at org.junit.runners.ParentRunner$1.evaluate(ParentRunner.java:173)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.ParentRunner.run(ParentRunner.java:220)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.apache.ibatis.executor.ExecutorException: Executor was closed.
at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:86)
at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:43)
at org.apache.ibatis.session.defaults.DefaultSqlSession.update(DefaultSqlSession.java:121)
... 26 more

Answer 1

SqlSession session =Mapper.openSession(TransactionIsolationLevel.READ_COMMITTED);或者参考FortuneJ中MyBatis的用法
参考地址www.cnblogs.com/mail-ricklee

Answer 2

SqlSession已经有的了，其他增删查没有问题

Answer 3

session.update(Channel.class.getName()+".updateChannel", c);你的错误在这里 你的session是全局的 
@Test
public void testUpdateChannel() {    
 Channel c = channeldao.getChannelById(11);     
c.setName("updatechannel");    
 channeldao.updateChannel(c); } 
做完查询操作 session就关闭了 所以 再更新的时候 session 就没有了遇到同样的错误了，哎

Answer 4

参考：http://blog.sina.com.cn/s/blog_8020e411010139q8.html