The reference I am giving is
JBoss specific but this question can be generic.
If I want to update single class file, and if I have exploded war directory, I can just replace it at runtime and then update the timestamp of web.xml. URLDeploymentScanner will sense it and will redeploy that particular application so I can see the new changes affected. But the downside is that all the connected users will have to re-login as old sessions would be lost.
Now the question is can this be achieved without redeploying the web application? ...by adding the class file at higher level (say server level) which has highest precedence for class loader and then it will refresh the class copy in JVM and for all new request, it will use this new copy?