de.laures.cewolf.dp
Class DataSourceXYDatasetProducer
java.lang.Object
de.laures.cewolf.dp.DataSourceXYDatasetProducer
- All Implemented Interfaces:
- DatasetProducer, java.io.Serializable
public class DataSourceXYDatasetProducer
- extends java.lang.Object
- implements DatasetProducer, java.io.Serializable
- Author:
- glaures
- See Also:
- Serialized Form
Method Summary |
java.lang.String |
getProducerId()
Tis method returns a unique ID for a DatasetProducer from this class. |
boolean |
hasExpired(java.util.Map params,
java.util.Date since)
This method is called by the Cewolf framework to check if a formerly
produced data can be reused. |
java.lang.Object |
produceDataset(java.util.Map<java.lang.String,java.lang.Object> params)
Produces a Dataset object. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
PARAM_SERIES_LIST
public static final java.lang.String PARAM_SERIES_LIST
- See Also:
- Constant Field Values
DataSourceXYDatasetProducer
public DataSourceXYDatasetProducer()
produceDataset
public java.lang.Object produceDataset(java.util.Map<java.lang.String,java.lang.Object> params)
throws DatasetProduceException
- Description copied from interface:
DatasetProducer
- Produces a
Dataset
object.
- Specified by:
produceDataset
in interface DatasetProducer
- Parameters:
params
- additional params for the dataset production. All elements
of this HashMap are of type java.io.Serializable
. This is
necessary to ensure the the serialization of the dataset producer into
the http session. To provide a producer with additional production
parameters the <param> tag is used (see tag library documentation).
It is recommended to synchronize implementations of this method to avoid concurrency problems.
- Returns:
- an object of type
org.jfree.data.general.Dataset
.
- Throws:
DatasetProduceException
- if an error occured during production- See Also:
DatasetProducer.produceDataset(Map)
hasExpired
public boolean hasExpired(java.util.Map params,
java.util.Date since)
- Description copied from interface:
DatasetProducer
- This method is called by the Cewolf framework to check if a formerly
produced data can be reused. If the data which had already been used
for chart rendering is still valid this method should return
true
.
If possible the Cewolf framework will try to reuse the rendered chart
image. If this is not possible because of some circumstances (e.g. the chart
had been removed from the image cache) the produceDataset method is called afterwards.
Therefore there is no guarantee that the dataset production is always
avoided if this method returns true.
- Specified by:
hasExpired
in interface DatasetProducer
- Parameters:
params
- the production parameters of the already produced datasince
- the point in time when the already produced data had been produced
- Returns:
true
if the data which had been produced with the
passed in parameters has expired since its creation, false
otherwise- See Also:
DatasetProducer.hasExpired(Map, Date)
getProducerId
public java.lang.String getProducerId()
- Description copied from interface:
DatasetProducer
- Tis method returns a unique ID for a DatasetProducer from this class.
Producers with the same ID are supposed to produce the same data when
called with the same parameters.
- Specified by:
getProducerId
in interface DatasetProducer
- Returns:
- the unique ID for instances of this poducer class
- See Also:
DatasetProducer.getProducerId()
cewolf tag library - web charts with JFreeChart