DynamoDBMapper is an Object-Relational Mapping (ORM) library provided by Amazon Web Services (AWS) as part of the AWS SDK for Java. It simplifies the interaction between Java applications and Amazon DynamoDB, a fully managed NoSQL database service.

Key features of DynamoDBMapper include :

Object Mapping : DynamoDBMapper allows developers to map Java objects directly to DynamoDB tables. Developers annotate their Java classes to define the mapping between object attributes and DynamoDB table attributes.

CRUD Operations : With DynamoDBMapper, developers can perform CRUD (Create, Read, Update, Delete) operations on Java objects stored in DynamoDB tables using simple method calls. This eliminates the need to write complex DynamoDB API calls manually.

Batch Operations : DynamoDBMapper supports batch operations, allowing developers to perform bulk reads and writes of multiple objects in a single request. This helps improve performance and reduce the number of network calls to DynamoDB.
Query and Scan Operations : DynamoDBMapper provides methods for executing queries and scans against DynamoDB tables. Developers can use query methods to retrieve objects based on specific conditions or scan methods to retrieve all objects in a table.

Automatic Table Creation and Updates : DynamoDBMapper can automatically create or update DynamoDB tables based on the Java class definitions. This simplifies the setup and management of DynamoDB tables, especially in development and testing environments.

Data Conversion : DynamoDBMapper handles the conversion between Java data types and DynamoDB data types automatically. It supports complex data structures such as lists, maps, and sets, making it easy to work with nested attributes.

Integration with AWS SDK for Java : DynamoDBMapper integrates seamlessly with the AWS SDK for Java, allowing developers to use other AWS services and features alongside DynamoDB.