# Package org.springframework.batch.core.repository.dao

Specific implementations of dao concerns.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  ExecutionContextDao | DAO interface for persisting and retrieving `ExecutionContext`s.
  JobExecutionDao | Data Access Object for job executions.
  JobInstanceDao | Data Access Object for job instances.
  StepExecutionDao |

- Class Summary
  Class | Description
  --- | ---
  AbstractJdbcBatchMetadataDao | Encapsulates common functionality needed by JDBC batch metadata DAOs - provides jdbcTemplate for subclasses and handles table prefixes.
  DefaultExecutionContextSerializer | An implementation of the `ExecutionContextSerializer` using the default serialization implementations from Spring (`DefaultSerializer` and `DefaultDeserializer`).
  JdbcExecutionContextDao | JDBC DAO for `ExecutionContext`.
  JdbcJobExecutionDao | JDBC implementation of `JobExecutionDao`.
  JdbcJobInstanceDao | JDBC implementation of `JobInstanceDao`.
  JdbcStepExecutionDao | JDBC implementation of `StepExecutionDao`. Allows customization of the tables names used by Spring Batch for step meta data via a prefix property. Uses sequences or tables (via Spring's `DataFieldMaxValueIncrementer` abstraction) to create all primary keys before inserting a new row.
  MapExecutionContextDao | In-memory implementation of `ExecutionContextDao` backed by maps.
  MapJobExecutionDao | In-memory implementation of `JobExecutionDao`.
  MapJobInstanceDao | In-memory implementation of `JobInstanceDao`.
  MapStepExecutionDao | In-memory implementation of `StepExecutionDao`.
  XStreamExecutionContextStringSerializer | Implementation that uses XStream and Jettison to provide serialization.

- Exception Summary
  Exception | Description
  --- | ---
  NoSuchObjectException | This exception identifies that a batch domain object is invalid, which is generally caused by an invalid ID.

## Package org.springframework.batch.core.repository.dao Description

Specific implementations of dao concerns.

Author:
  Michael Minella