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The Waikato Environment for Knowledge Analysis (WEKA), a machine
learning workbench. This is the stable version. Apart from bugfixes, this version
does not receive any other updates.
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see Class for encapsulating data to be transferred between Knowledge Flow steps
* over a particular connection type. Typical usage involves constructing a Data
* object with a given connection name and then setting one or more pieces of
* "payload" data to encapsulate. Usually there is a primary payload that is
* associated with the connection name itself (there is a constructor that takes
* both the connection name and the primary payload data). Further auxiliary
* data items can be added via the setPayloadElement() method.
*
* Standard connection types are defined as constants in the StepManager class.
* There is nothing to prevent clients from using their own connection types (as
* these are just string identifiers).
*
* Typical usage in a client step (transferring an training instances object):
*
*
*
* Instances train = ...
* Data myData = new Data(StepManager.CON_TRAININGSET, train);
* getStepManager().outputData(myData);
*
*
* @author mhall{[at]}pentaho{[dot]}com
* @version $Revision: $
*/
public class Data implements Serializable {
/**
* For serialization
*/
private static final long serialVersionUID = 239235113781041619L;
/** The source of this data */
protected Step m_sourceStep;
/**
* The connection name for this Data - determines which downstream steps will
* receive the data.
*/
protected String m_connectionName;
/** The payload */
protected Map m_payloadMap =
new LinkedHashMap();
/**
* Empty constructor - no connection name; no payload
*/
public Data() {
}
/**
* Construct a Data object with just a connection name
*
* @param connectionName the connection name
*/
public Data(String connectionName) {
setConnectionName(connectionName);
}
/**
* Construct a Data object with a connection name and a primary payload object
* to associate with the connection name
*
* @param connectionName connection name
* @param primaryPayload primary payload object (i.e. is keyed against the
* connection name)
*/
public Data(String connectionName, Object primaryPayload) {
this(connectionName);
setPayloadElement(connectionName, primaryPayload);
}
/**
* Set the source step of producing this Data object
*
* @param sourceStep the source step
*/
public void setSourceStep(Step sourceStep) {
m_sourceStep = sourceStep;
}
/**
* Get the source step producing this Data object
*
* @return the source step producing the data object
*/
public Step getSourceStep() {
return m_sourceStep;
}
/**
* Set the connection name for this Data object
*
* @param name the name of the connection
*/
public void setConnectionName(String name) {
m_connectionName = name;
}
/**
* Get the connection name associated with this Data object
*
* @return the connection name
*/
public String getConnectionName() {
return m_connectionName;
}
/**
* Get the primary payload of this data object (i.e. the data associated with
* the connection name)
*
* @param the type of the primary payload
* @return the primary payload data (or null if there is no data associated
* with the connection)
*/
@SuppressWarnings("unchecked")
public T getPrimaryPayload() {
return (T) m_payloadMap.get(m_connectionName);
}
/**
* Get a payload element from this Data object. Standard payload element names
* (keys) can be found as constants defined in the StepManager class.
*
* @param name the name of the payload element to get
* @return the named payload element, or null if it does not exist in this
* Data object
*/
@SuppressWarnings("unchecked")
public T getPayloadElement(String name) {
return (T) m_payloadMap.get(name);
}
/**
* Get a payload element from this Data object. Standard payload element names
* (keys) can be found as constants defined in the StepManager class.
*
* @param name the name of the payload element to get
* @param defaultValue a default value if the named element does not exist
* @param the type of the payload element to get
* @return the payload element, or the supplied default value.
*/
public T getPayloadElement(String name, T defaultValue) {
Object result = getPayloadElement(name);
if (result == null) {
return defaultValue;
}
return (T) result;
}
/**
* Set a payload element to encapsulate in this Data object. Standard payload
* element names (keys) can be found as constants defined in the StepManager
* class.
*
* @param name the name of the payload element to encapsulate
* @param value the value of the payload element
*/
public void setPayloadElement(String name, Object value) {
m_payloadMap.put(name, value);
}
/**
* Clear all payload elements from this Data object
*/
public void clearPayload() {
m_payloadMap.clear();
}
}