无法将类强制转换为同一类-在Glassfish服务器应用程序中重新启动后

Question

I use Glassfish 2 and if I restart it, I have web applications that raise the following error: "Class package1.Model1 cannot be cast to package1.Model1".

Then, I have to deploy the applications again and they return to work.

How could I solve this problem?

Answer 1

A class is likely being loaded in multiple classloaders, creating two incompatible versions of that class. But without any details of how the app is setup and deployed, I cannot say much more.

When is this error occurring exactly? Also post more details of your setup.

Answer 2

I had this issue with a WAR in an EAR, where the WAR and EAR both included the jar in question. Posting in case someone else has this problem.

Don't include your jars in your wars if you're already including them in your ear.

<build>
    <finalName>WebApp</finalName>
    <plugins>
        <plugin>
            <artifactId>maven-war-plugin</artifactId>
            <version>2.3</version>
            <configuration>


            <packagingExcludes>WEB-INF/lib/*.jar</packagingExcludes>


                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <classpathPrefix>lib/</classpathPrefix>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
</build>