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spring-batch/spring-batch-docs/modules/ROOT/pages/appendix.adoc
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[[listOfReadersAndWriters]]
[appendix]
[[list-of-itemreaders-and-itemwriters]]
= List of ItemReaders and ItemWriters
[[itemReadersAppendix]]
== Item Readers
.Available Item Readers
[options="header"]
|===============
|Item Reader|Description|Thread-safe
|`AbstractItemStreamItemReader`|Abstract base class that combines the `ItemStream` and `ItemReader` interfaces.|Yes
|`AbstractItemCountingItemStreamItemReader`|Abstract base class that provides basic
restart capabilities by counting the number of items returned from
an `ItemReader`.|No
|`AbstractPagingItemReader`|Abstract base class that provides basic paging features|No
|`AbstractPaginatedDataItemReader`|Abstract base class that provides basic paging features based on Spring Data's
paginated facilities|No
|`AggregateItemReader`|An `ItemReader` that delivers a list as its
item, storing up objects from the injected `ItemReader` until they
are ready to be packed out as a collection. This class must be used
as a wrapper for a custom `ItemReader` that can identify the record
boundaries. The custom reader should mark the beginning and end of
records by returning an `AggregateItem` which responds `true` to its
query methods (`isHeader()` and `isFooter()`). Note that this reader
is not part of the library of readers provided by Spring Batch
but given as a sample in `spring-batch-samples`.|Yes
|`AmqpItemReader`|Given a Spring `AmqpTemplate`, it provides
synchronous receive methods. The `receiveAndConvert()` method
lets you receive POJO objects.|Yes
|`KafkaItemReader`|An `ItemReader` that reads messages from an Apache Kafka topic.
It can be configured to read messages from multiple partitions of the same topic.
This reader stores message offsets in the execution context to support restart capabilities.|No
|`FlatFileItemReader`|Reads from a flat file. Includes `ItemStream`
and `Skippable` functionality. See link:readersAndWriters.html#flatFileItemReader["`FlatFileItemReader`"].|No
|`ItemReaderAdapter`|Adapts any class to the
`ItemReader` interface.|Yes
|`JdbcCursorItemReader`|Reads from a database cursor over JDBC. See
link:readers-and-writers/database.html#cursorBasedItemReaders["`Cursor-based ItemReaders`"].|No
|`JdbcPagingItemReader`|Given an SQL statement, pages through the rows,
such that large datasets can be read without running out of
memory.|Yes
|`JmsItemReader`|Given a Spring `JmsOperations` object and a JMS
destination or destination name to which to send errors, provides items
received through the injected `JmsOperations#receive()`
method.|Yes
|`JpaCursorItemReader`|Executes a JPQL query and iterates over the returned result set|No
|`JpaPagingItemReader`|Given a JPQL query, pages through the
rows, such that large datasets can be read without running out of
memory.|Yes
|`ListItemReader`|Provides the items from a list, one at a time.|No
|`MongoItemReader`|Given a `MongoOperations` object and a JSON-based MongoDB
query, provides items received from the `MongoOperations#find()` method.|Yes
|`Neo4jItemReader`|Given a `Neo4jOperations` object and the components of a
Cyhper query, items are returned as the result of the Neo4jOperations.query
method.|Yes
|`RepositoryItemReader`|Given a Spring Data `PagingAndSortingRepository` object,
a `Sort`, and the name of method to execute, returns items provided by the
Spring Data repository implementation.|Yes
|`StoredProcedureItemReader`|Reads from a database cursor resulting from the
execution of a database stored procedure. See link:readersAndWriters.html#StoredProcedureItemReader[`StoredProcedureItemReader`]|No
|`StaxEventItemReader`|Reads over StAX. see link:readersAndWriters.html#StaxEventItemReader[`StaxEventItemReader`].|No
|`JsonItemReader`|Reads items from a Json document. see link:readersAndWriters.html#JsonItemReader[`JsonItemReader`].|No
|`AvroItemReader`|Reads items from a resource containing serialized Avro objects.|No
|`LdifReader`|Reads items from a LDIF resource and returns them as `LdapAttributes`|No
|`MappingLdifReader`|Reads items from a LDIF resource and uses a `RecordMapper` to map them to domain objects|No
|===============
[[itemWritersAppendix]]
== Item Writers
.Available Item Writers
[options="header"]
|===============
|Item Writer|Description|Thread-safe
|`AbstractItemStreamItemWriter`|Abstract base class that combines the`ItemStream` and`ItemWriter` interfaces.|Yes
|`AmqpItemWriter`|Given a Spring `AmqpTemplate`, provides
for a synchronous `send` method. The `convertAndSend(Object)`
method lets you send POJO objects.|Yes
|`CompositeItemWriter`|Passes an item to the `write` method of each item
in an injected `List` of `ItemWriter` objects.|Yes
|`FlatFileItemWriter`|Writes to a flat file. Includes `ItemStream` and
Skippable functionality. See link:readersAndWriters.html#flatFileItemWriter["`FlatFileItemWriter`"].|No
|`ItemWriterAdapter`|Adapts any class to the
`ItemWriter` interface.|Yes
|`JdbcBatchItemWriter`|Uses batching features from a
`PreparedStatement`, if available, and can
take rudimentary steps to locate a failure during a
`flush`.|Yes
|`JmsItemWriter`|Using a `JmsOperations` object, items are written
to the default queue through the `JmsOperations#convertAndSend()` method.|Yes
|`JpaItemWriter`|This item writer is JPA `EntityManager`-aware
and handles some transaction-related work that a non-"`JPA-aware`"
`ItemWriter` would not need to know about and
then delegates to another writer to do the actual writing.|Yes
|`KafkaItemWriter`|Using a `KafkaTemplate` object, items are written to the default topic through the
`KafkaTemplate#sendDefault(Object, Object)` method by using a `Converter` to map the key from the item.
A delete flag can also be configured to send delete events to the topic.|No
|`MimeMessageItemWriter`|Using Spring's `JavaMailSender`, items of type `MimeMessage`
are sent as mail messages.|Yes
|`MongoItemWriter`|Given a `MongoOperations` object, items are written
through the `MongoOperations.save(Object)` method. The actual write is delayed
until the last possible moment before the transaction commits.|Yes
|`Neo4jItemWriter`|Given a `Neo4jOperations` object, items are persisted through the
`save(Object)` method or deleted through the `delete(Object)`, as dictated by the
`ItemWriter's` configuration|Yes
|`PropertyExtractingDelegatingItemWriter`|Extends `AbstractMethodInvokingDelegator`
creating arguments on the fly. Arguments are created by retrieving
the values from the fields in the item to be processed (through a
`SpringBeanWrapper`), based on an injected array of field
names.|Yes
|`RepositoryItemWriter`|Given a Spring Data `CrudRepository` implementation,
items are saved through the method specified in the configuration.|Yes
|`StaxEventItemWriter`|Uses a `Marshaller` implementation to
convert each item to XML and then writes it to an XML file by using
StAX.|No
|`JsonFileItemWriter`|Uses a `JsonObjectMarshaller` implementation to
convert each item to Json and then writes it to a Json file.|No
|`AvroItemWriter`|Serializes data to an `WritableResource` using Avro|No
|`ListItemWriter`|Item writer that writes items to a `List`.|No
|===============