RE: [cinjug-users] WebApps: how not to deploy?

["Mascolino, Mark R." <mark.mascolino@xxxxxx>]

 

In the servlet's init() you could do a little try/catch action to look for the absence of a particular 1.4 only class.  That's when you would throw the ServletException to veto the Servlet's loading.  Still does nothing to prevent the application as a whole from loading, just that particular servlet.

 

m

 

Mark Mascolino
Hewlett Packard
Managed Services - GTS
eBusiness Services - P&G Cincinnati
+1 513.983.4714
mark.mascolino@xxxxxx

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-----Original Message-----
From: Robert Casto [mailto:robert@xxxxxxxxxxxxx]
Sent: Wednesday, September 01, 2004 4:13 PM
To: users@xxxxxxxxxx
Subject: RE: [cinjug-users] WebApps: how not to deploy?

Wouldn’t you want to avoid the ClassNotFoundException as well? It is not severity of the problem but the fact that the problem exists at all. I too have run into this and I think Joe Herbers has a good point. There needs to be some way of knowing before hand that the deployment is going to be able to run before using a browser to test it.

 

I guess all you can do is see what is installed on the server. I would be curious to know what you guys come up with as it would help me greatly with upgrades at various customer sites, especially if the sites are running older version of software.

Robert Casto
Phone: 513-755-2221
robert@xxxxxxxxxxxxx

 

 

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From: James Carman [mailto:james@xxxxxxxxxxxxxxxxxxxx]
Sent: Wednesday, September 01, 2004 4:06 PM
To: users@xxxxxxxxxx
Subject: RE: [cinjug-users] WebApps: how not to deploy?

 

However, if that servlet class was compiled using the JDK 1.4 compiler, it would throw an error, because the JVM wouldn’t know how to load the class.  You need to tell your compiler to compile your classes so that they are compatible with the 1.3 releases.  They can still depend upon the 1.4-specific classes, but the class file format would be compatible with the older JVMs.  That way, the worst thing that could happen would probably be a ClassNotFoundException unless you’re using assertions.

 

-----Original Message-----
From: Mascolino, Mark R. [mailto:mark.mascolino@xxxxxx]
Sent: Wednesday, September 01, 2004 3:59 PM
To: users@xxxxxxxxxx
Subject: RE: [cinjug-users] WebApps: how not to deploy?

 

I don't believe that there is any cross-app server way of having an app veto its deployment.  The best you could do is a load-on-startup servlet that checked things out and threw a ServletException in the case that everything wasn't ok.  Not perfect, but at least you should get a failure message right away.

Mark Mascolino
Hewlett Packard
Managed Services - GTS
eBusiness Services - P&G Cincinnati
+1 513.983.4714
mark.mascolino@xxxxxx

The information transmitted is intended solely for the individual or entity to which it is addressed and may contain Hewlett Packard Company confidential and/or privileged material. Any review, retransmission, dissemination or other use of or taking action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you have received this email in error please contact the sender and delete the material from any computer.

-----Original Message-----
From: Herbers, Joe [mailto:herbers@xxxxxxx]
Sent: Wednesday, September 01, 2004 3:48 PM
To: users@xxxxxxxxxx
Subject: [cinjug-users] WebApps: how not to deploy?

Let’s say you have a web application that requires Java 1.4.  Is there a good way to prevent it from deploying on an appserver if the appserver is only running 1.3?

 

What I’ve noticed by default on at least one appserver is that you won’t see an issue till a client hits a JSP page that references a class file, at which point the client gets a message like “The major.minor version '48.0' is too recent for this tool to understand.”

 

This isn’t very clear!  Rather than this appearing to the first user who hits the server, we’re thinking perhaps it would be better to print an error message on startup.  However, since the output may be buried in a log file somewhere (for example on Oracle 9i’s AppServer) it seems like the only way to get attention is to prevent deployment of the war as well.  What do you think?

 

Mascolino, Mark R..vcf
Description: Mascolino, Mark R..vcf