Does Google App Engine Java support Hot Deployment in Eclipse?

Question

It doesn't seem to do this by default, which is pretty shocking to me given all the other stuff they've set up to make development easy. Is there a way to enable this? If not, anybody know why it isn't supported?

Answer 1

This is an open feature request on the App Engine Issue Tracker. You should vote on it there.

FWIW, it does work with JSP as expected (they get invalidated and recompiled when you update them).

Answer 2

There is JRebel that can help you with this http://englove.blogspot.com/2010/09/appengine-hot-deploy-on-mac.html

But using JRebel i had troubles with GWT in Development Mode.

BUt, there is a simplier way to do it. You can have hot deploy of your server clases if you debug your application in Eclipse.

Debug As -> Web Application

That's all! :)

Answer 3

I realized that local server reloads when I modify and save the appengine-web.xml file, so i created a build.xml file with this instructions and runs from eclipse+ant, so I have a hot deploy

<?xml version="1.0"?>

<project default="main" basedir=".">
<property name="appengine" location="${basedir}/war/WEB-INF/appengine-web.xml" />


<target name="main">
    <echo message="REINICIANDO SERVIDOR LOCAL ${appengine}" />
    <touch file="${appengine}" />
</target>

</project>

Answer 4

I work with App Engine 1.9.2, and it is already working not only for JSPs, but Servlets and Java code as well.

If your project is Maven-based, and you start your server with mvn appengine:devserver, after modifying some code, all you need to do is

mvn package

and refresh the page in your browser.