Migrate from Java 8 to Java 21 with Jakarta EE 10

[devin-ai-integration]

Summary

Full migration of the project from Java 8 / Java EE (javax namespace) to Java 21 / Jakarta EE 10 (jakarta namespace). This touches every layer: Maven compiler settings, dependencies, Jetty plugin, XML descriptors, and Java source imports.

Key changes:

• Parent POM: Compiler source/target → 21, added maven.compiler.release=21
• Dependencies: javax.servlet-api:3.1.0 → jakarta.servlet-api:6.0.0, cdi-api:1.2 → jakarta.enterprise.cdi-api:4.0.1
• Plugins: maven-war-plugin 2.5 → 3.4.0, jetty-maven-plugin 9.x → jetty-ee10-maven-plugin 12.0.14, weld-servlet 2.x → weld-servlet-shaded 5.1.2.Final
• XML configs: web.xml/web-overwrite.xml updated to Jakarta EE 10 schema (version 6.0); jetty-env.xml and jetty-context.xml updated for Jetty 12 EE10 class names
• Java sources: All javax.servlet.*, javax.inject.*, javax.enterprise.*, javax.annotation.* imports → jakarta.* equivalents. javax.naming.* (JDK) correctly left unchanged.
• READMEs: Updated version references and documentation links

Build compiles cleanly with mvn clean install under JDK 21.

Updates since last revision

• Fixed jetty-context.xml: Changed <Set name="hiddenClassMatcher"> to <Get name="hiddenClassMatcher"> so that exclude() is called on the existing ClassMatcher object rather than on the WebAppContext (which has no exclude() method). Caught by Devin Review.

Review & Testing Checklist for Human

• Verify jetty-context.xml Jetty 12 classloader config — the old Jetty 9 serverClasses negative pattern was replaced with <Get name="hiddenClassMatcher"><Call name="exclude"> for DecoratingListener. The <Set>→<Get> bug was fixed, but the overall approach (class name, exclude pattern) still needs runtime validation to confirm Weld integrates correctly with Jetty 12's classloading.
• Verify contextXml placement inside <webApp> in the Jetty EE10 Maven plugin config — it was moved from a top-level plugin config element to nested under <webApp>. Confirm this matches the Jetty 12 EE10 plugin API.
• Verify ManagerObjectFactory class name — jetty-env.xml references org.jboss.weld.resources.ManagerObjectFactory which was correct for Weld 2.x. Confirm this factory class still exists in Weld 5.1.2.Final.
• Run mvn jetty:run in jetty-maven-cdi/ and hit http://localhost:8080/ — compilation passed but CDI/Weld/Jetty runtime wiring was NOT tested. Verify the page renders "Hello web-overwrite.xml!" (confirming JNDI + CDI injection both work).
• Check console output for BeanManager injection succeeded and BeanManager JNDI lookup succeeded during Jetty startup — this confirms the JNDI binding in jetty-env.xml is wired correctly with the new Jakarta class references.

Notes

• javax.naming.* imports in DefaultGreeting.java are intentionally unchanged — these are JDK classes, not Jakarta EE.
• The old javax.el exclusion on cdi-api was removed since the Jakarta CDI API no longer bundles it.
• beans.xml is empty and was left unchanged (still valid for CDI discovery).

Link to Devin session: https://app.devin.ai/sessions/f5b0f927228b4f749afaacbc48a1d173
Requested by: @jerryoliphant-cog

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[devin-ai-integration]

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[devin-ai-integration]

Devin Review found 1 potential issue.

View 4 additional findings in Devin Review.

[devin-ai-integration]

🔴 <Set> used instead of <Get> in jetty-context.xml causes exclude() to be called on wrong object

In Jetty XML configuration, <Set name="hiddenClassMatcher"> evaluates its child elements in the scope of the parent WebAppContext object, then calls setHiddenClassMatcher(result). The nested <Call name="exclude"> therefore tries to call exclude() on the WebAppContext (which has no such method) rather than on the ClassMatcher object. This will fail at runtime, preventing the CDI/Weld integration from being correctly configured.

The fix is to use <Get> instead of <Set>, which retrieves the existing ClassMatcher via getHiddenClassMatcher() and makes it the target for the nested <Call name="exclude">.

Suggested change

	<Set name="hiddenClassMatcher">
	<Call name="exclude">
	<Arg>
	<Array type="java.lang.String">
	<Item>org.eclipse.jetty.ee10.servlet.DecoratingListener</Item>
	</Array>
	</Arg>
	</Call>
	</Set>
	<Get name="hiddenClassMatcher">
	<Call name="exclude">
	<Arg>
	<Array type="java.lang.String">
	<Item>org.eclipse.jetty.ee10.servlet.DecoratingListener</Item>
	</Array>
	</Arg>
	</Call>
	</Get>

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[devin-ai-integration]

Good catch — <Set> would call exclude() on the WebAppContext which doesn't have that method. Fixed in 343f882 by changing to <Get> so that the existing ClassMatcher is retrieved first and exclude() is called on it.