datahandler

A data handler (or DataHandler in some ecosystems) is a software component that manages data input and output between producers and consumers. It provides an abstraction layer that hides the details of data sources and destinations and standardizes operations such as reading, writing, and validating data. Data handlers are used in APIs, data integration, and message processing.

Typical responsibilities include data validation, format conversion, serialization and deserialization, streaming, and error handling. They may also manage metadata, provenance, access control, and caching. By decoupling data access from business logic, data handlers improve reuse, testability, and maintainability.

Common implementations define an interface or abstract class named DataHandler or similar, with methods to load and store data and report status. Design patterns such as adapters and bridges are used to support multiple formats (JSON, XML, CSV) and sources (files, databases, network services).

In specific ecosystems, the term is used for concrete components. For example, in Java, javax.activation.DataHandler encapsulates data with a MIME type and delegates retrieval to a DataSource, a pattern seen in email attachments and web services. In data engineering, data handlers are elements of ETL pipelines.

The term is broad and context-dependent, with definitions varying by framework. It emphasizes modular, data-centric design and is often part of broader data management or integration strategies.