Package org.springframework.batch.item.database

Class HibernatePagingItemReader<T>

java.lang.Object
org.springframework.batch.item.ItemStreamSupport
org.springframework.batch.item.support.AbstractItemStreamItemReader<T>
org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader<T>
org.springframework.batch.item.database.AbstractPagingItemReader<T>
org.springframework.batch.item.database.HibernatePagingItemReader<T>
All Implemented Interfaces:
ItemReader<T>, ItemStream, ItemStreamReader<T>, org.springframework.beans.factory.InitializingBean
public class HibernatePagingItemReader<T> extends AbstractPagingItemReader<T> implements org.springframework.beans.factory.InitializingBean
ItemReader for reading database records built on top of Hibernate and reading only up to a fixed number of items at a time. It executes an HQL query when initialized is paged as the AbstractItemCountingItemStreamItemReader.read() method is called. The query can be set directly using setQueryString(String), a named query can be used by setQueryName(String), or a query provider strategy can be supplied via setQueryProvider(HibernateQueryProvider).

The reader can be configured to use either StatelessSession sufficient for simple mappings without the need to cascade to associated objects or standard hibernate Session for more advanced mappings or when caching is desired. When stateful session is used it will be cleared in the AbstractItemCountingItemStreamItemReader.update(ExecutionContext) method without being flushed (no data modifications are expected).

The implementation is thread-safe in between calls to AbstractItemCountingItemStreamItemReader.open(ExecutionContext), but remember to use saveState=false if used in a multi-threaded client (no restart available).

Since:
2.1
Author:
Dave Syer

  • Constructor Details

    • HibernatePagingItemReader

      public HibernatePagingItemReader()

  • Method Details

    • setParameterValues

      public void setParameterValues(Map<String,Object> parameterValues)
      The parameter values to apply to a query (map of name:value).
      Parameters:
      parameterValues - the parameter values to set

    • setQueryName

      public void setQueryName(String queryName)
      A query name for an externalized query. Either this or the { query string or the { query provider should be set.
      Parameters:
      queryName - name of a hibernate named query

    • setFetchSize

      public void setFetchSize(int fetchSize)
      Fetch size used internally by Hibernate to limit amount of data fetched from database per round trip.
      Parameters:
      fetchSize - the fetch size to pass down to Hibernate

    • setQueryProvider

      public void setQueryProvider(HibernateQueryProvider<? extends T> queryProvider)
      A query provider. Either this or the {query string or the {query name should be set.
      Parameters:
      queryProvider - Hibernate query provider

    • setQueryString

      public void setQueryString(String queryString)
      A query string in HQL. Either this or the { query provider or the { query name should be set.
      Parameters:
      queryString - HQL query string

    • setSessionFactory

      public void setSessionFactory(org.hibernate.SessionFactory sessionFactory)
      The Hibernate SessionFactory to use the create a session.
      Parameters:
      sessionFactory - the SessionFactory to set

    • setUseStatelessSession

      public void setUseStatelessSession(boolean useStatelessSession)
      Can be set only in uninitialized state.
      Parameters:
      useStatelessSession - true to use StatelessSession false to use standard hibernate Session

    • afterPropertiesSet

      public void afterPropertiesSet() throws Exception
      Description copied from class: AbstractPagingItemReader
      Check mandatory properties.
      Specified by:
      afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean
      Overrides:
      afterPropertiesSet in class AbstractPagingItemReader<T>
      Throws:
      Exception
      See Also:
      • InitializingBean.afterPropertiesSet()

    • doOpen

      protected void doOpen() throws Exception
      Description copied from class: AbstractItemCountingItemStreamItemReader
      Open resources necessary to start reading input.
      Overrides:
      doOpen in class AbstractPagingItemReader<T>
      Throws:
      Exception - Allows subclasses to throw checked exceptions for interpretation by the framework

    • doReadPage

      protected void doReadPage()
      Specified by:
      doReadPage in class AbstractPagingItemReader<T>

    • doJumpToPage

      protected void doJumpToPage(int itemIndex)
      Specified by:
      doJumpToPage in class AbstractPagingItemReader<T>

    • doClose

      protected void doClose() throws Exception
      Description copied from class: AbstractItemCountingItemStreamItemReader
      Close the resources opened in AbstractItemCountingItemStreamItemReader.doOpen().
      Overrides:
      doClose in class AbstractPagingItemReader<T>
      Throws:
      Exception - Allows subclasses to throw checked exceptions for interpretation by the framework