Vaadin 24.9 / Java 25 - vaadin-maven-plugin - Fails with "class file version 69"

Flow
1

Hi Team,

I am attempting to update our codebase to use Vaadin 24.9.0 on Java 25. Now the good news is if I build it and run the application in development mode, everything works as expected.

However, when I attempt to build on Java 25 with mvn clean install -Pproduction I get a failure in the vaadin-maven-plugin plugin.

The relevant stacktrace is:

Caused by: java.lang.IllegalArgumentException: Unsupported class file major version 69
    at org.objectweb.asm.ClassReader.<init> (ClassReader.java:200)
    at org.objectweb.asm.ClassReader.<init> (ClassReader.java:180)
    at org.objectweb.asm.ClassReader.<init> (ClassReader.java:166)
    at org.objectweb.asm.ClassReader.<init> (ClassReader.java:288)
    at com.vaadin.flow.server.frontend.scanner.FrontendAnnotatedClassVisitor.visitClass (FrontendAnnotatedClassVisitor.java:104)
    at com.vaadin.flow.server.frontend.scanner.FrontendAnnotatedClassVisitor.visit (FrontendAnnotatedClassVisitor.java:116)

(would have been nice if it also showed me which class was causing the issue)

At first I thought this was because my project itself was compiling to Java 25 class versions (which I take it the org.objectweb.asm library you link to doesn’t support yet). But with some further debugging I was able to isolate where it was throwing the error:

As you can see this is deep inside the JVM. Which means I cannot use Java 25 to invoke the vaadin-maven-plugin plugin.

image
image1920Ă—668 85.5 KB

For now, I will carry on building the project with Java 21 and deploying on Java 25. Though would appreciate if you could have a look and suggest a workaround, or update the library.

Thanks,

2

If you define asm in your pom with a more recent version you can workaround this.

1 Like
3

Actually Vaadin uses asm 9.8 that supports Java 25.
Can you please double check the build logs to verify that your project isn’t providing an old version?

4

BTW, if you run maven with -X flag you should get more info about the failure

5

Very useful responses to this, thanks everyone.

By putting in (hacking) a reference to the latest ASM library I was able to resolve this:

<dependency>
            <groupId>org.ow2.asm</groupId>
            <artifactId>asm</artifactId>
            <version>9.8</version>
        </dependency>

Looking at dependencies pulling in the old asm version, there is quite a few (not least an older version of SpringBoot).

Can’t wait until everyone adopts this: JEP 484: Class-File API
All this classfile black magic in frameworks is always such a pain to debug when upgrading.

6

Note that we recommend using Spring Boot 3.5 with Vaadin 24.9 and that Spring Boot version should already have an ASM version that works with Java 25.

7

Indeed - though it has to be a specific version of SpringBoot 3.5 → 3.5.6

We were on 3.5.3 before and that pulls in the wrong ASM version.

1 Like
8 
mvn dependency:tree -Dincludes="org.ow2.asm:asm"

spring-boot-starter-test:jar:3.5.6:test
 \- net.minidev:json-smart:jar:2.5.2:test
    \- net.minidev:accessors-smart:jar:2.5.2:test
       \- org.ow2.asm:asm:jar:9.7.1:compile

looks like spring-boot-starter-test using an older version of “asm” so compilation with vaadin-maven-plugin fails with vaadin 24.9 and spring boot 3.5.6 and java 25

you have to put the “vaadin-spring-boot-starter” dependency on the top of your dependenies in your pom.xm. this will fix the java 25 problem.

[INFO] --- dependency:3.8.1:tree (default-cli) @ dh64web ---
[INFO] com.dh64web:dh64web:jar:0.0.1-SNAPSHOT
[INFO] \- com.vaadin:vaadin-spring-boot-starter:jar:24.9.0:compile
[INFO]    \- com.vaadin:vaadin-spring:jar:24.9.0:compile
[INFO]       \- com.vaadin:flow-server:jar:24.9.0:compile
[INFO]          \- org.ow2.asm:asm:jar:9.8:compile
9

image

maven is not able to resolve the conflict with the version correct depending on the order of dependencies. would it be possible to solve this problem in a cleaner way than letting the user pay attention to the order of dependencies? could the required version for “asm” be specified in the vaadin-bom?

10

NO. do not even think about it for a second.