ClassNotFoundException for multi-project web project when running in Tomcat through WTP

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1

Hi,

my project structure looks like

myproject
- common
- dao
- webmvc
- webapp  <-- actual webapp, depends on the other sub projects

The settings.gradle of “myproject” contains an include of all the sub projects.

“webapp” is the project I want to run/deploy to Tomcat. It depends on the other subprojects: common, dao and webmvc.

Gradle does not show any errors. I can run the war task and I get a war file that looks fine to me, including web.xml. The WAR file includes all the dependencies in WEB-INF/lib as expected.

But when I run “webapp” project in Eclipse (2025-03) on my Tomcat 10.1, I cannot open the web application in my browser. At the first attempt to navigate to it, a ClassNotFoundException is logged for the servlet located in webmvc dependency JAR. Tomcat says “Marking servlet [SimpleServlet] as unavailable”. All subsequent access attempts lead to 404.

Only classes directly in “webapp” are found. Classes from the dependencies are not found.

Even more weird: If I run

dir C:\eclipse\myworkspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps\webapp\WEB-INF\lib\*

which is the folder that Eclipse WTP seems to use as “webapps” folder for Tomcat, I see all the JARs and these contain the classes that Tomcat cannot find…

I’ve included ‘eclipse-wtp’ and ‘war’ plugins in the build.gradle of all (sub) projects.

The build.gradle file of “webapp” looks like this:

plugins {
	id 'eclipse-wtp'
	id 'war'
}
repositories {
	mavenCentral()
}
dependencies {
	// https://mvnrepository.com/artifact/jakarta.servlet/jakarta.servlet-api
	compileOnly group: 'jakarta.servlet', name: 'jakarta.servlet-api', version: '6.0.0'
	implementation project(':common')
	implementation project(':dao')
	implementation project(':webmvc')
}
java {
	sourceCompatibility = JavaVersion.VERSION_17
}
compileJava {
	options.release = 17
	options.encoding = "UTF-8"
}
compileTestJava {
	options.release = 17
	options.encoding = "UTF-8"
}
testing {
	suites {
		test {
			useJUnitJupiter()
		}
	}
}
eclipse {
	wtp {
		facet {
			facet name: "jst.web", version: "6.0"  // 5.0 doesn't help either
		}
	}
}
war {
	webAppDirectory = file('src/main/webapp')
}

Any advice? :sob: