Implementation:Datahub project Datahub MetadataChangeProposalWrapper Java

Knowledge Sources	Datahub_project_Datahub
Domains	Metadata_Integration, Event_Serialization
Last Updated	2026-02-10 00:00 GMT

Overview

Description

MetadataChangeProposalWrapper is a generic, type-safe Java class that simplifies the creation of MetadataChangeProposal events in the DataHub Java SDK. It wraps the core fields needed for a metadata change proposal: entity type, entity URN, change type, aspect, and aspect name. The class provides a step builder pattern that enforces a mandatory construction order (entity type, entity URN, change type, aspect), reducing the chance of creating invalid proposals.

The class attempts to automatically infer the aspect name from the aspect's schema properties via the "Aspect" key in the schema's property map. If inference fails, the aspect name must be explicitly provided through the builder's aspectName() method.

Usage

Used across the DataHub Java SDK and integration modules to construct metadata change proposal events that are subsequently serialized by EventFormatter and emitted to GMS or Kafka. The step builder pattern is the preferred construction method.

Code Reference

Source Location

metadata-integration/java/datahub-event/src/main/java/datahub/event/MetadataChangeProposalWrapper.java

Signature

@Value
@Slf4j
@AllArgsConstructor
public class MetadataChangeProposalWrapper<T extends DataTemplate> {

    String entityType;
    String entityUrn;
    ChangeType changeType;
    T aspect;
    String aspectName;

    public static EntityTypeStepBuilder builder()

    public static MetadataChangeProposalWrapper create(
        Consumer<EntityTypeStepBuilder> builderConsumer)
}

Step Builder Interfaces:

public interface EntityTypeStepBuilder {
    EntityUrnStepBuilder entityType(String entityType);
}

public interface EntityUrnStepBuilder {
    ChangeStepBuilder entityUrn(String entityUrn);
    ChangeStepBuilder entityUrn(Urn entityUrn);
}

public interface ChangeStepBuilder {
    AspectStepBuilder upsert();
}

public interface AspectStepBuilder {
    Build aspect(DataTemplate aspect);
}

public interface Build {
    MetadataChangeProposalWrapper build();
    Build aspectName(String aspectName);
}

Import

import datahub.event.MetadataChangeProposalWrapper;

I/O Contract

Inputs

Parameter	Type	Description
entityType	String	The entity type (e.g., "dataset", "chart")
entityUrn	String or Urn	The entity URN; validated for correctness on set
changeType	ChangeType	Currently only UPSERT is supported through the builder
aspect	DataTemplate	The aspect data template to include in the proposal
aspectName	String (optional)	Overrides auto-inferred aspect name

Outputs

Return Type	Description
MetadataChangeProposalWrapper	Immutable value object containing all fields for a metadata change proposal

Exceptions:

• EventValidationException -- if URN parsing fails or required fields are missing at build time

Usage Examples

// Using the step builder
MetadataChangeProposalWrapper mcpw = MetadataChangeProposalWrapper.builder()
    .entityType("dataset")
    .entityUrn("urn:li:dataset:(urn:li:dataPlatform:mysql,db.table,PROD)")
    .upsert()
    .aspect(datasetProperties)
    .build();

// Using the consumer-based create method
MetadataChangeProposalWrapper mcpw = MetadataChangeProposalWrapper.create(
    b -> b.entityType("dataset")
          .entityUrn("urn:li:dataset:(urn:li:dataPlatform:mysql,db.table,PROD)")
          .upsert()
          .aspect(datasetProperties));

// Direct constructor (all args)
MetadataChangeProposalWrapper mcpw = new MetadataChangeProposalWrapper(
    "dataset",
    "urn:li:dataset:(urn:li:dataPlatform:mysql,db.table,PROD)",
    ChangeType.UPSERT,
    datasetProperties,
    "datasetProperties");

Related Pages

• Datahub_project_Datahub_MetadataEventFormatter -- Serializes MetadataChangeProposalWrapper to wire format