org.knime.core.node.port
Class AbstractPortObject

java.lang.Object
  org.knime.core.node.port.AbstractPortObject

All Implemented Interfaces:

PortObject

Direct Known Subclasses:

ImagePortObject, PMMLPreprocPortObject

public abstract class AbstractPortObject
extends Object
implements PortObject

Abstract implementation of general port objects. Extending this class (as opposed to just implementing PortObject) has the advantage that the serializing methods are enforced by abstract methods (rather than defining a static method with a particular name as given by the interface).

Subclasses must provide an empty no-arg constructor with public scope (which will be used to restore the content). They are encouraged to also provide a convenience access member such as

   public static final PortType TYPE = new PortType(FooModelPortObject.class);
 

and to narrow the return type of the getSpec() method. Derived classes don't need to provide a static serializer method as required by the interface PortObject.

Author:

Bernd Wiswedel, University of Konstanz

Nested Class Summary

Nested classes/interfaces inherited from interface org.knime.core.node.port.PortObject

PortObject.PortObjectSerializer<T extends PortObject>

Constructor Summary

AbstractPortObject()
Public no-arg constructor.

Method Summary

static PortObject.PortObjectSerializer<AbstractPortObject>	getPortObjectSerializer() Abstract serializer method as required by interface PortObject.
protected abstract void	load(PortObjectZipInputStream in, PortObjectSpec spec, ExecutionMonitor exec) Loads the content into the freshly instantiated object.
protected abstract void	save(PortObjectZipOutputStream out, ExecutionMonitor exec) Saves this object to an output stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.knime.core.node.port.PortObject

getSpec, getSummary, getViews

Constructor Detail

AbstractPortObject

public AbstractPortObject()

Public no-arg constructor. Subclasses must also provide such a constructor in order to allow the serializer to instantiate them using reflection.

Method Detail

getPortObjectSerializer

public static final PortObject.PortObjectSerializer<AbstractPortObject> getPortObjectSerializer()

Abstract serializer method as required by interface PortObject.

Returns:

A serializer that reads/writes any implementation of this class.

save

protected abstract void save(PortObjectZipOutputStream out,
                             ExecutionMonitor exec)
                      throws IOException,
                             CanceledExecutionException

Saves this object to an output stream. This method represents the implementation of #savePortObject(PortObject, PortObjectZipOutputStream, ExecutionMonitor).

Parameters:

out - A clean directory to write to.

exec - For progress/cancelation.

Throws:

IOException - If writing fails

CanceledExecutionException - If canceled.

load

protected abstract void load(PortObjectZipInputStream in,
                             PortObjectSpec spec,
                             ExecutionMonitor exec)
                      throws IOException,
                             CanceledExecutionException

Loads the content into the freshly instantiated object. This method is called at most once in the life time of the object (after the serializer has created a new object using the public no-arg constructor.)

Parameters:

in - To restore from

spec - The accompanying spec (which can be safely cast to the expected class).

exec - For progress/cancelation.

Throws:

IOException - If reading fails.

CanceledExecutionException - If canceled.