Unreadable Error Message

Hello All,

I am using PostgreSQL 7.2 with JBoss, and using JDBC to connect the db.
However, it throws an exception when execute query. The error message is
unreadable.
And the Java System properties is: user.language=en; user.region=US. It
should not relate to localisation......

[Default] ????¡Â????W?L??i?d???C
[Default]  at org.postgresql.jdbc2.ResultSet.getString(ResultSet.java:166)
[Default]  at
org.jboss.pool.jdbc.ResultSetInPool.getString(ResultSetInPool.java:654)
[Default]  at
org.jboss.security.auth.spi.DatabaseServerLoginModule.getRoleSets(DatabaseSe
rverLoginModule.java:156)
[Default]  at
org.jboss.security.auth.spi.AbstractServerLoginModule.commit(AbstractServerL
oginModule.java:123)
[Default]  at java.lang.reflect.Method.invoke(Native Method)
[Default]  at
javax.security.auth.login.LoginContext.invoke(LoginContext.java:595)
[Default]  at
javax.security.auth.login.LoginContext.access$000(LoginContext.java:125)
[Default]  at
javax.security.auth.login.LoginContext$3.run(LoginContext.java:531)
[Default]  at java.security.AccessController.doPrivileged(Native Method)
[Default]  at
javax.security.auth.login.LoginContext.invokeModule(LoginContext.java:528)
[Default]  at
javax.security.auth.login.LoginContext.login(LoginContext.java:450)
[Default]  at
org.jboss.security.plugins.JaasSecurityManager.defaultLogin(JaasSecurityMana
ger.java:396)
[Default]  at
org.jboss.security.plugins.JaasSecurityManager.authenticate(JaasSecurityMana
ger.java:363)
[Default]  at
org.jboss.security.plugins.JaasSecurityManager.isValid(JaasSecurityManager.j
ava:219)
[Default]  at
org.jboss.tomcat.security.JBossSecurityMgrRealm.authenticate(JBossSecurityMg
rRealm.java:129)
[Default]  at
org.apache.tomcat.core.ContextManager.doAuthenticate(ContextManager.java:852
)
[Default]  at
org.apache.tomcat.core.RequestImpl.getRemoteUser(RequestImpl.java:341)
[Default]  at
org.apache.tomcat.facade.HttpServletRequestFacade.getRemoteUser(HttpServletR
equestFacade.java:251)
[Default]  at
com.y28shop.control.web.MainServlet.doGet(MainServlet.java:170)
[Default]  at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
[Default]  at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
[Default]  at
org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
[Default]  at org.apache.tomcat.core.Handler.service(Handler.java:287)
[Default]  at
org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
[Default]  at
org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:81
2)
[Default]  at
org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
[Default]  at
org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC
onnectionHandler.java:213)
[Default]  at
org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
[Default]  at
org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
[Default]  at java.lang.Thread.run(Thread.java:479)

What should i do? Where can i find the log of db?

Thank you!
Leo Tai