org.pentaho.reporting.engine.classic.core.states
Class EmptyDataFactory

java.lang.Object
  extended by org.pentaho.reporting.engine.classic.core.states.EmptyDataFactory
All Implemented Interfaces:
Serializable, Cloneable, DataFactory

public class EmptyDataFactory
extends Object
implements DataFactory

A datafactory that does not do any real work.

Author:
Thomas Morgner
See Also:
Serialized Form

Field Summary
 
Fields inherited from interface org.pentaho.reporting.engine.classic.core.DataFactory
QUERY_LIMIT, QUERY_TIMEOUT
 
Constructor Summary
EmptyDataFactory()
           
 
Method Summary
 void cancelRunningQuery()
          Attempts to cancel the query process that is generating the data for this data factory.
 Object clone()
           
 void close()
          Closes the data factory and frees all resources held by this instance.
 DataFactory derive()
          Returns a copy of the data factory that is not affected by its anchestor and holds no connection to the anchestor anymore.
 String[] getQueryNames()
          Returns all known query-names.
 void initialize(org.pentaho.reporting.libraries.base.config.Configuration configuration, org.pentaho.reporting.libraries.resourceloader.ResourceManager resourceManager, org.pentaho.reporting.libraries.resourceloader.ResourceKey contextKey, ResourceBundleFactory resourceBundleFactory)
          Initializes the data factory and provides new context information.
 boolean isQueryExecutable(String query, DataRow parameters)
          Checks whether the query would be executable by this datafactory.
 void open()
          Opens the data factory.
 TableModel queryData(String query, DataRow parameters)
          Queries a datasource.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EmptyDataFactory

public EmptyDataFactory()
Method Detail

queryData

public TableModel queryData(String query,
                            DataRow parameters)
                     throws ReportDataFactoryException
Queries a datasource. The string 'query' defines the name of the query. The Parameterset given here may contain more data than actually needed for the query.

The parameter-dataset may change between two calls, do not assume anything, and do not hold references to the parameter-dataset or the position of the columns in the dataset.

Specified by:
queryData in interface DataFactory
Parameters:
query - the query string
parameters - the parameters for the query
Returns:
the result of the query as table model.
Throws:
ReportDataFactoryException - if an error occured while performing the query.

derive

public DataFactory derive()
Returns a copy of the data factory that is not affected by its anchestor and holds no connection to the anchestor anymore. A data-factory will be derived at the beginning of the report processing.

Specified by:
derive in interface DataFactory
Returns:
a copy of the data factory.

open

public void open()
          throws ReportDataFactoryException
Opens the data factory. This initializes everything. Performing queries on data factories which have not yet been opened will result in exceptions.

Specified by:
open in interface DataFactory
Throws:
ReportDataFactoryException - if an error occured while opening the datafactory resources.

close

public void close()
Closes the data factory and frees all resources held by this instance.

Specified by:
close in interface DataFactory

initialize

public void initialize(org.pentaho.reporting.libraries.base.config.Configuration configuration,
                       org.pentaho.reporting.libraries.resourceloader.ResourceManager resourceManager,
                       org.pentaho.reporting.libraries.resourceloader.ResourceKey contextKey,
                       ResourceBundleFactory resourceBundleFactory)
Description copied from interface: DataFactory
Initializes the data factory and provides new context information. Initialize is always called before the datafactory has been opened by calling DataFactory#open.

Specified by:
initialize in interface DataFactory
Parameters:
configuration - the current report configuration.
resourceManager - the report's resource manager.
contextKey - the report's context key to access resources relative to the report location.
resourceBundleFactory - the report's resource-bundle factory to access localization information.

clone

public Object clone()
Specified by:
clone in interface DataFactory
Overrides:
clone in class Object

isQueryExecutable

public boolean isQueryExecutable(String query,
                                 DataRow parameters)
Checks whether the query would be executable by this datafactory. This performs a rough check, not a full query.

Specified by:
isQueryExecutable in interface DataFactory
Parameters:
query -
parameters -
Returns:

getQueryNames

public String[] getQueryNames()
Description copied from interface: DataFactory
Returns all known query-names. A data-factory may accept more than the query-names returned here.

Specified by:
getQueryNames in interface DataFactory
Returns:
the known query names.

cancelRunningQuery

public void cancelRunningQuery()
Description copied from interface: DataFactory
Attempts to cancel the query process that is generating the data for this data factory. If it is not possible to cancel the query, this call should be ignored.

Specified by:
cancelRunningQuery in interface DataFactory