How to see JSP changes without redeployment

In this article we will learn how to see automatic changes in your Jakarta Server Pages without the need of redeploying your applications.

Prerequisites

To allow automatic reload of JSP pages you need to use an exploded deployment format. To learn more about the different types of deployment on WildFly, we recommend checking this article: How to deploy applications on WildFly

How to enable automatic changes in JSP pages

Next, let’s see how to enable automatic changes for JSP pages. The attribute which you need to configure is development, which is part of the servlet-container configuration of your Undertow server:

<servlet-container name="default">
                <jsp-config development="true"/>
                <websockets/>
</servlet-container>

To set it from the Command Line, you can use the following command:

/subsystem=undertow/servlet-container=default/setting=jsp:write-attribute(name=development,value=true)

Automatic reloading in JBoss EAP 6

On the other hand, if you are using an older version of the application server (such as JBoss EAP 6), the attribute to set is still development but it belongs to the configuration of the jsp-configuration element. For example:

<subsystem xmlns="urn:jboss:domain:web:1.0" default-virtual-server="default-host">
...
    <configuration>
        <jsp-configuration development="true"/>
    </configuration>
</subsystem>