tomcat日志错误，大家给指点一二 亟待解决

2008-05-21 01:15:36 StandardContext[/] Velocity   [info] ResourceManager : found /core/webshow/detail.vm with loader org.apache.velocity.tools.view.servlet.WebappLoader
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 93,column 66] : $user.userName is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 93,column 110] : $user.newsNum is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 6,column 20] : $F is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 9,column 26] : $F is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 40] : $F is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 66] : $F is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 97] : $F is not a valid reference.
2008-05-21 01:15:36 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 147] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [info] ResourceManager : found /core/webshow/detail.vm with loader org.apache.velocity.tools.view.servlet.WebappLoader
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 93,column 66] : $user.userName is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 93,column 110] : $user.newsNum is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 6,column 20] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 9,column 26] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 40] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 66] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 97] : $F is not a valid reference.
2008-05-21 01:37:31 StandardContext[/] Velocity   [warn] org.apache.velocity.runtime.exception.ReferenceException: reference : template = /core/webshow/detail.vm [line 12,column 147] : $F is not a valid reference.
2008-05-21 01:47:58 ApplicationDispatcher[/] Servlet.service() for servlet jsp threw exception
java.lang.OutOfMemoryError