Package net.sf.jasperreports.j2ee.ejbql

Class JRJpaQueryExecuter

java.lang.Object
net.sf.jasperreports.engine.query.JRAbstractQueryExecuter
net.sf.jasperreports.j2ee.ejbql.JRJpaQueryExecuter
All Implemented Interfaces:
JRQueryExecuter
public class JRJpaQueryExecuter extends JRAbstractQueryExecuter
EJBQL query executer that uses the Java Persistence API.

To use EJBQL in queries, an javax.persistence.EntityManager is needed. When running or filling reports the em need to be supplied with the named parameter EjbqlConstants.PARAMETER_JPA_ENTITY_MANAGER.

Example: 

 Map parameters = new HashMap();
 EntityManager em = emf.createEntityManager();
 parameters.put(EjbqlConstants.PARAMETER_JPA_ENTITY_MANAGER, em);
 JasperRunManager.runReportToPdfFile(fileName, parameters);

When dealing with large result sets, pagination can be used by setting the PROPERTY_JPA_QUERY_PAGE_SIZE property in the report template.

Example: 

 <property name="net.sf.jasperreports.ejbql.query.page.size" value="100"/>

Implementation-specific query hints can be set either using report properties in the report template, or by supplying the named parameter EjbqlConstants.PARAMETER_JPA_QUERY_HINTS_MAP containing a java.util.Map with named/value query hints.

Example using report property: 

 <property name="net.sf.jasperreports.ejbql.query.hint.fetchSize" value="100"/>
The name of the query hint need to be prefixed with net.sf.jasperreports.ejbql.query.hint.. Above example will set a query hint with the name fetchSize and the String value 100.

Example using map: 

 Map hints = new HashMap();
 hints.put("fetchSize", 100);
 hints.put("anyName", anyObject());
 Map parameters = new HashMap();
 EntityManager em = emf.createEntityManager();
 parameters.put(EjbqlConstants.PARAMETER_JPA_ENTITY_MANAGER, em);
 parameters.put(EjbqlConstants.PARAMETER_JPA_QUERY_HINTS_MAP, hints);
 JasperRunManager.runReportToPdfFile(fileName, parameters);
Note that when using report properties only String values can be set as query hint. When using a query hints map, any Object can be set as value.
Author:
Marcel Overdijk (marceloverdijk@hotmail.com)
See Also:

  • Field Details

    • CANONICAL_LANGUAGE

      public static final String CANONICAL_LANGUAGE
      See Also:

    • PROPERTY_JPA_QUERY_PAGE_SIZE

      public static final String PROPERTY_JPA_QUERY_PAGE_SIZE
      Property specifying the number of result rows to be retrieved at once.

      Result pagination is implemented by javax.persistence.Query.setFirstResult() and javax.persistence.Query.setMaxResults().

      By default, all the rows are retrieved (no result pagination is performed).

      See Also:

    • PROPERTY_JPA_QUERY_HINT_PREFIX

      public static final String PROPERTY_JPA_QUERY_HINT_PREFIX
      Property specifying the prefix for EJBQL query hints.
      See Also:

  • Constructor Details

  • Method Details

    • getCanonicalQueryLanguage

      protected String getCanonicalQueryLanguage()
      Description copied from class: JRAbstractQueryExecuter
      Returns a canonical query language for this query executer implementation.

      The canonical language is used to retrieve extensions for the query executer.

      The default implementation returns the runtime query language used in the dataset, but query executer implementations should override this method and return a fixed language.

      Overrides:
      getCanonicalQueryLanguage in class JRAbstractQueryExecuter
      Returns:
      a canonical query language

    • createDatasource

      public JRDataSource createDatasource() throws JRException
      Description copied from interface: JRQueryExecuter
      Executes the query and creates a JRDataSource out of the result.
      Returns:
      a JRDataSource wrapping the query execution result.
      Throws:
      JRException

    • createQuery

      protected void createQuery(String queryString)
      Creates the EJBQL query object.
      Parameters:
      queryString - the query string

    • createResultDatasource

      protected JRDataSource createResultDatasource()
      Creates a data source out of the query result.
      Returns:
      the data source

    • close

      public void close()
      Description copied from interface: JRQueryExecuter
      Closes resources kept open during the data source iteration.

      This method is called after the report is filled or the dataset is iterated. If a resource is not needed after the data source has been created, it should be released at the end of createDatasource.

    • cancelQuery

      public boolean cancelQuery() throws JRException
      Description copied from interface: JRQueryExecuter
      Cancels the query if it's currently running.

      This method will be called from a different thread if the client decides to cancel the filling process.

      Returns:
      true if and only if the query was running and it has been canceled
      Throws:
      JRException

    • getParameterReplacement

      protected String getParameterReplacement(String parameterName)
      Description copied from class: JRAbstractQueryExecuter
      Returns the replacement text for a query parameter.
      Specified by:
      getParameterReplacement in class JRAbstractQueryExecuter
      Parameters:
      parameterName - the parameter name
      Returns:
      the replacement text
      See Also:

    • getEjbqlParameterName

      protected String getEjbqlParameterName(String parameterName)

    • getResultList

      public List<?> getResultList()
      Runs the query by calling javax.persistence.Query.getResultList.

      All the result rows are returned.

      Returns:
      the result of the query as a list

    • getResultList

      public List<?> getResultList(int firstIndex, int resultCount)
      Returns a page of the query results by calling javax.persistence.Query.getResultList.
      Parameters:
      firstIndex - the index of the first row to return
      resultCount - the number of rows to return
      Returns:
      result row list