Tomcat 8.5 in Eclipse 4.7.0 not seeing changed HTML files

Question

Tomcat in Eclipse is ignoring source HTML changes and not publishing them, even though it worked fine before.

I have Windows 10 Pro 64-bit, with Tomcat 8.5.6 installed in C:\bin\tomcat. I am running Eclipse Java EE 4.7.0, installed in D:\bin\eclipse (a separate volume). Tomcat has been added as an 8.5 server. My workspace is in D:\workspace . I have a Maven web application in D:\workspace\project, with HTML file index.html in src/main/webapp. My project has the "Dynamic Web Module 3.1" facet enabled. I have added a "Tomcat v8.5 Server at localhost" in the "Servers" tab, and I have added my project to the server. I have turned off caching in my browser.

With the above configuration, on the machine laptop1 I would start the server and I could access my index.html in a browser via localhost. If I edited index.html, as soon as I saved it Tomcat would quickly show that the files needed publishing, and then would auto-publish the changed file. I could refresh the browser and see the changed HTML file immediately. I worked in this development environment for six to nine months.

I configured a virtually identical machine laptop2 by installing the same version of Tomcat in C:\bin\tomcat as before. I connected the volume D: to laptop2. I built the project and started Tomcat. I was able to open the browser and see index.html via localhost.

But now if I edit index.html, even inside Eclipse, the changes do not show up in the browser.

• I have used F5 to refresh the project tree.
• I have verified that src/main/webapp/index.html has new content and has its timestamp updated.
• The content and timestamp of the files in target/m2e-wtp/web-resources do not change after editing index.html, even if I restart the server.
• I have removed and re-added the web app from the server in Eclipse, with no change in behavior.
• I have removed and re-added the "Tomcat v8.5 Server" from the "Server" tab, with no change in behavior.
• I have removed and re-added the "Apache Tomcat v8.5" runtime environment from Eclipse, with no change in behavior.
• I have completely disabled Windows Defender using the group policy editor for both laptop1 and laptop2.

I am at a loss to think of what else I could check. I do not know if moving from one system to the other had anything to do with Tomcat stopping recognizing and publishing file changes.

Answer 1

Somehow "Build Automatically" had been disabled.

Yes, the source of all these problems is that somehow in Eclipse the option Project > Build Automatically had been turned off. I don't know how. I don't know when. But once re-enabled, everything started working again exactly as it had been before.

I probably would have found this sooner or (much) later, but I stumbled across an answer to another question in which @mico mentioned this in passing. I am grateful.