Error ClassNotFoundException: com.mongodb.MongoClient

[victoralc]

I'm trying to setup a batch application with quarkus and jberet extension. I need to read data from database and write in a csv file and therefore I need the jberet-support module.

I added these dependencies required from jberet-support

<dependency>
    <groupId>io.quarkiverse.jberet</groupId>
    <artifactId>quarkus-jberet</artifactId>
    <version>2.6.0</version>
</dependency>
<dependency>
    <groupId>org.jberet</groupId>
    <artifactId>jberet-support</artifactId>
    <version>3.0.0.Final</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.20.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.20.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.20</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-jaxb-annotations</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-csv</artifactId>
</dependency>
<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>dynamodb-enhanced</artifactId>
    <version>2.34.6</version>
</dependency>

but when I start quarkus dev the build fails on:

Caused by: java.lang.ClassNotFoundException: com.mongodb.MongoClient

I tried adding some mongo dependencies but still fails.

The quarkus version I'm using is 3.28.2

Any ideas?

[radcortez]

Most likely, it also requires the Quarkus Mongo extension, but it may require some more stuff. I'll have a look.

Related to #432

[radcortez]

So, the Mongo drivers are marked as provided in the JBeret Parent POM. The dependency must be explicitly included.

Also, it is using the old driver version, where Quarkus is using the new one, so while it should work, it is not going to benefit from Quarkus enhancements. I'm having a look.

[radcortez]

Unfortunately, the Mongo dependencies required by jberet-support seem incompatible with the Mongo Quarkus extension.

We either have to update Mongo in JBeret, or provide our own reader / writer. I'm probably more inclined toward the second one. Even if we update Mongo version and fix that problem, there is still the design issue with jberet-support to provide all the readers and writers in the same artifact, which would require heavy refactoring and breaking changes.

[victoralc]

Thanks for the update @radcortez. Currently I am doing POC on porting a spring batch application to quarkus using jberet but having those issues it holds me a bit back. Other option for me could be migrate the jobs as batchlets and not using readers/writers but in the end will lose the benefit of them. I will follow up on this issue.

[radcortez]

What other readers / writers do you need?

[victoralc]

In Spring Batch I usually use the standard jdbc (JdbcCursorItemReader / JdbcBatchItemWriter) and for csv (FlatFileItemReader / Writer). So in quarkus I would need the equivalent of them which is in jberet-support.

[radcortez]

I did some work on this, and I think the best option is for the extension to provide its own reader / writer. There are some configurations available in the jberet-support Mongo reader / writer that do not make sense in a Quarkus content (like JNDI lookup).

There is no way to reuse an existing client, so it will always create a new one (unless we pass it around with JNDI, which we don't support).

While we could probably go in and make some changes to make it more Quarkus friendly, it does feel to be all workarounds.

I'll be pushing a couple of PR's to add the Mongo support from our side, fully integrated with the already existing Quarkus Mongo Client Extension.