Re: Pass info between Tomcat Valve and Filter
An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Hi Jon All, Thanks for your information. It's very helpful. I've been looking at ValveContext but did not find anything useful. Yes, I tried to pass the info object along as an attribute of ServletRequest. But problem occured with the retrieval of the object in the Filter, where ServletRequest.getAttribute() successfully located my attribute, but promtted a ClassCastException when the returned Object was casted back to the original info class. It seems Tomcat somehow lost the class structure of the original info class...? Anyone got a clue of this? Many thanks. Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Jon, To answer your query, I'm using a custom valve to instrument Tomcat with response time monitoring, as part of the project I'm working on... http://web.comlab.ox.ac.uk/oucl/research/areas/softeng/eWLM/ Cheers, Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Pass info between Tomcat Valve and Filter
One possible cause: The component that store your object find the class through a different classloader than the component that tries to retrieve the object. Where do you store the class/jar for the stored object ? -Original Message- From: Rui Zhang [mailto:[EMAIL PROTECTED] Sent: Friday, May 21, 2004 6:53 PM To: Tomcat Users List Cc: [EMAIL PROTECTED] Subject: Re: Pass info between Tomcat Valve and Filter Hi Jon All, Thanks for your information. It's very helpful. I've been looking at ValveContext but did not find anything useful. Yes, I tried to pass the info object along as an attribute of ServletRequest. But problem occured with the retrieval of the object in the Filter, where ServletRequest.getAttribute() successfully located my attribute, but promtted a ClassCastException when the returned Object was casted back to the original info class. It seems Tomcat somehow lost the class structure of the original info class...? Anyone got a clue of this? Many thanks. Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Rui Zhang wrote: Hi Jon All, Thanks for your information. It's very helpful. I've been looking at ValveContext but did not find anything useful. Yes, I tried to pass the info object along as an attribute of ServletRequest. But problem occured with the retrieval of the object in the Filter, where ServletRequest.getAttribute() successfully located my attribute, but promtted a ClassCastException when the returned Object was casted back to the original info class. It seems Tomcat somehow lost the class structure of the original info class...? Anyone got a clue of this? Sounds like a ClassLoader problem. The valve is going to use tomcat's libraries. The filter will use the webapps's libraries, in preference to tomcat's libraries. If the class is in the webapp's libraries, it's going to try to cast it to an instance of the webapp version of the class, which will be different from the version the valve created. (Classes with different classloaders are different, even if they happen to be identical.) - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Yes, indeed. I got around it by retrieving the info using getClass(), getField() etc. Thanks again. Rui On Fri, 21 May 2004, Carl Howells wrote: Rui Zhang wrote: Hi Jon All, Thanks for your information. It's very helpful. I've been looking at ValveContext but did not find anything useful. Yes, I tried to pass the info object along as an attribute of ServletRequest. But problem occured with the retrieval of the object in the Filter, where ServletRequest.getAttribute() successfully located my attribute, but promtted a ClassCastException when the returned Object was casted back to the original info class. It seems Tomcat somehow lost the class structure of the original info class...? Anyone got a clue of this? Sounds like a ClassLoader problem. The valve is going to use tomcat's libraries. The filter will use the webapps's libraries, in preference to tomcat's libraries. If the class is in the webapp's libraries, it's going to try to cast it to an instance of the webapp version of the class, which will be different from the version the valve created. (Classes with different classloaders are different, even if they happen to be identical.) - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Cool. I guess a Valve is good for that type of thing :) I think Carl and Ralph are right about the ClassClassException being a ClassLoader issue. I've seen similar things before when using custom Realms, JNDI resources etc. Our build process generates a minimal jar for deploying to common/lib which contains all the classes needed by the container classloaders. These classes are excluded from the webapp jars and all is happy. You have to be really careful about dependencies though or virtually all your webapp ends up in common/lib. Try jarring up your info object and putting in common/lib (or common/classes). Or you could use reflection as I've just read in your reply to Ralph ;) Good weekend all, Jon Rui Zhang wrote: Jon, To answer your query, I'm using a custom valve to instrument Tomcat with response time monitoring, as part of the project I'm working on... http://web.comlab.ox.ac.uk/oucl/research/areas/softeng/eWLM/ Cheers, Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Hi All, Thanks very much for your incisive comments. Similar problem, but it seems much trickier to pass info from a Filter to a Valve. No attribute is associated with a ServletResponse. And when I try to cast it to HttpServletResponse to make use of its addHeader() method, my program simply hangs... Any clue? Thanks again. Best, Rui On Fri, 21 May 2004, Jon Wingfield wrote: Cool. I guess a Valve is good for that type of thing :) I think Carl and Ralph are right about the ClassClassException being a ClassLoader issue. I've seen similar things before when using custom Realms, JNDI resources etc. Our build process generates a minimal jar for deploying to common/lib which contains all the classes needed by the container classloaders. These classes are excluded from the webapp jars and all is happy. You have to be really careful about dependencies though or virtually all your webapp ends up in common/lib. Try jarring up your info object and putting in common/lib (or common/classes). Or you could use reflection as I've just read in your reply to Ralph ;) Good weekend all, Jon Rui Zhang wrote: Jon, To answer your query, I'm using a custom valve to instrument Tomcat with response time monitoring, as part of the project I'm working on... http://web.comlab.ox.ac.uk/oucl/research/areas/softeng/eWLM/ Cheers, Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Maybe the failure of addHeader() is because the response has already been committed by the time it reaches the Filter? but, still, how can i pass info from a fliter back to a valve? Cheers, Rui On Fri, 21 May 2004, Rui Zhang wrote: Hi All, Thanks very much for your incisive comments. Similar problem, but it seems much trickier to pass info from a Filter to a Valve. No attribute is associated with a ServletResponse. And when I try to cast it to HttpServletResponse to make use of its addHeader() method, my program simply hangs... Any clue? Thanks again. Best, Rui On Fri, 21 May 2004, Jon Wingfield wrote: Cool. I guess a Valve is good for that type of thing :) I think Carl and Ralph are right about the ClassClassException being a ClassLoader issue. I've seen similar things before when using custom Realms, JNDI resources etc. Our build process generates a minimal jar for deploying to common/lib which contains all the classes needed by the container classloaders. These classes are excluded from the webapp jars and all is happy. You have to be really careful about dependencies though or virtually all your webapp ends up in common/lib. Try jarring up your info object and putting in common/lib (or common/classes). Or you could use reflection as I've just read in your reply to Ralph ;) Good weekend all, Jon Rui Zhang wrote: Jon, To answer your query, I'm using a custom valve to instrument Tomcat with response time monitoring, as part of the project I'm working on... http://web.comlab.ox.ac.uk/oucl/research/areas/softeng/eWLM/ Cheers, Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Pass info between Tomcat Valve and Filter
Never mind, I've found a not very tidy way around it by customizing the output stream of the response. But if anyone knows about a better way of doing it, pls let me know. Thanks. Rui On Fri, 21 May 2004, Rui Zhang wrote: Maybe the failure of addHeader() is because the response has already been committed by the time it reaches the Filter? but, still, how can i pass info from a fliter back to a valve? Cheers, Rui On Fri, 21 May 2004, Rui Zhang wrote: Hi All, Thanks very much for your incisive comments. Similar problem, but it seems much trickier to pass info from a Filter to a Valve. No attribute is associated with a ServletResponse. And when I try to cast it to HttpServletResponse to make use of its addHeader() method, my program simply hangs... Any clue? Thanks again. Best, Rui On Fri, 21 May 2004, Jon Wingfield wrote: Cool. I guess a Valve is good for that type of thing :) I think Carl and Ralph are right about the ClassClassException being a ClassLoader issue. I've seen similar things before when using custom Realms, JNDI resources etc. Our build process generates a minimal jar for deploying to common/lib which contains all the classes needed by the container classloaders. These classes are excluded from the webapp jars and all is happy. You have to be really careful about dependencies though or virtually all your webapp ends up in common/lib. Try jarring up your info object and putting in common/lib (or common/classes). Or you could use reflection as I've just read in your reply to Ralph ;) Good weekend all, Jon Rui Zhang wrote: Jon, To answer your query, I'm using a custom valve to instrument Tomcat with response time monitoring, as part of the project I'm working on... http://web.comlab.ox.ac.uk/oucl/research/areas/softeng/eWLM/ Cheers, Rui On Fri, 21 May 2004, Jon Wingfield wrote: An invocation of a Tomcat Valve gives you a Request object. This is a facade to a ServletRequest, which you can access via the getRequest() method. You could set your info object as an attribute on the ServletRequest. This should then be visible to your filter. http://jakarta.apache.org/tomcat/tomcat-4.1-doc/catalina/docs/api/index.html Just curious, why the custom Valve? Jon Rui Zhang wrote: Hi all, I'm trying to pass some info (say, as an Object) between a valve and a filter. Is anyone aware of a effective way to do this within the context of Tomcat? Many thanks. Best, Rui - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
