[NIFI-3832] AvroRecordSetWriter initial validation fails with NullPointerException

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 1.3.0
• Component/s: Extensions
• Assignee: Koji Kawamura
• Reporter: Koji Kawamura
• Created: 08/May/17 10:30
• Updated: 12/May/17 02:52
• Resolved: 09/May/17 18:12

Description

AvroRecordSetWriter overrides default value for SCHEMA_WRITE_STRATEGY to AVRO_EMBEDDED. However getRequiredSchemaFields uses SCHEMA_WRITE_STRATEGY constant defined in its super class to get value, which has SCHAMA_NAME_ATTRIBUTE as its default value.

So, at the initial validation (before user hit apply button), following code go through the if statement and results in NPE:

    @Override
    protected Set<SchemaField> getRequiredSchemaFields(final ValidationContext validationContext) {
        final String writeStrategyValue = validationContext.getProperty(SCHEMA_WRITE_STRATEGY).getValue();
        if (writeStrategyValue.equalsIgnoreCase(AVRO_EMBEDDED.getValue())) {
            return requiredSchemaFields;
        }

        return super.getRequiredSchemaFields(validationContext);
    }

Here is the stacktrace:

2017-05-08 19:19:22,749 ERROR [NiFi Web Server-158] o.a.n.c.AbstractConfiguredComponent Failed to perform validation of AvroRecordSetWriter[id=e78aac25-015b-1000-f931-33bf517d5e42]
java.lang.NullPointerException: null
        at org.apache.nifi.serialization.SchemaRegistryRecordSetWriter.getRequiredSchemaFields(SchemaRegistryRecordSetWriter.java:138)
        at org.apache.nifi.avro.AvroRecordSetWriter.getRequiredSchemaFields(AvroRecordSetWriter.java:138)
        at org.apache.nifi.serialization.SchemaRegistryRecordSetWriter.customValidate(SchemaRegistryRecordSetWriter.java:147)
        at org.apache.nifi.components.AbstractConfigurableComponent.validate(AbstractConfigurableComponent.java:126)
        at org.apache.nifi.controller.AbstractConfiguredComponent.getValidationErrors(AbstractConfiguredComponent.java:460)
        at org.apache.nifi.controller.service.StandardControllerServiceNode.getValidationErrors(StandardControllerServiceNode.java:506)
        at org.apache.nifi.controller.AbstractConfiguredComponent.getValidationErrors(AbstractConfiguredComponent.java:448)
        at org.apache.nifi.web.api.dto.DtoFactory.createControllerServiceDto(DtoFactory.java:1381)
        at org.apache.nifi.web.StandardNiFiServiceFacade.createControllerServiceEntity(StandardNiFiServiceFacade.java:30

Issue Links

• links to: GitHub Pull Request #1768