Tomcat and Eclipse Zero Turnaround Deployment

Question

I want to be able to deploy code changes to Tomcat (near instantly), while I\'m developing in Eclipse.

So far, I have my output from Eclipse placing the built classe

Answer 1

Maybe the Web Tools Project of Eclipse with auto-redeploy enabled will help you? Add a server, open properties and under Publishing you will see a radiobutton saying "Automatically publish when resources changes". This will result in a redeploy if classes changes otherwise just overwrites resources. You can install WTP via a built in update site (Eclipse only), so check out your software updates. It is free for most servers but it does not support certain Websphere features?

Answer 2

For these cases I set the eclipse build output to WEB-INF/classes as you have done and create a context file with the docBase set to the webapp folder (parent of WEB-INF) in the project. This is manually placed in conf/Catalina/localhost (assuming default configs for some elements of server.xml). End result is tomcat ends up serving from the development directory. So, change a servlet or other class and it is updated to the classes folder. Save a jsp and it is immediately available.

If project structured like:

src
|-main
  |-webapp
    |-images
    |-js
    |-WEB-INF
      |-jsp
      |-classes

Then context would be like:

<?xml version="1.0" encoding="UTF-8"?>
<Context path="/path" reloadable="true" 
    docBase="<pathtoproject>/src/main/webapp" />

Answer 3

Try the Spring Loaded JVM agent I've described in the following answer: https://stackoverflow.com/a/37064672/1034436

While that has worked for my Spring web application, this should work with vanilla Eclipse + WTP + Tomcat + Dynamic Web Applications since Spring Loaded works on the JVM/classloading level.

You will still need to use the "Automatically publish when resources changes" as mentioned by @toomasr in his answer. However, you must also disable "Module auto reload by default" option as well. If you already added/published modules from Eclipse to Tomcat, then disable "Auto Reload" for each web module (via the Tomcat config page's Modules tab). That should prevent Tomcat from reloading the application when a single class file is updated, which I suspect is what all that reload/wait time is.