org.geotools.feature
Class FeatureResultsIteration

java.lang.Object
  org.geotools.feature.FeatureResultsIteration

public class FeatureResultsIteration

extends java.lang.Object

The FeatureCollectionIteration provides a depth first traversal of a FeatureCollection which will call the provided call-back Handler. Because of the complex nature of Features, which may have other Features (or even a collection of Features) as attributes, the handler is repsonsible for maintaining its own state as to where in the traversal it is recieving events from. Many handlers will not need to worry about state.

Implementation Notes: The depth first visitation is implemented through recursion. The limits to recursion depending on the settings in the JVM, but some tests show a 2 argument recursive having a limit of ~50000 method calls with a stack size of 512k (the standard setting).

Nested Class Summary

static interface

FeatureResultsIteration.Handler A callback handler for the iteration of the contents of a FeatureCollection.

Field Summary

protected FeatureResultsIteration.Handler

handler A callback handler for the iteration of the contents of a FeatureCollection.

Constructor Summary

FeatureResultsIteration(FeatureResultsIteration.Handler handler, org.geotools.data.FeatureResults features)
Create a new FeatureResultsIteration with the given handler and collection.

Method Summary

void	iterate() Start the iteration.
protected void	iterate(org.geotools.data.FeatureReader reader) Perform the actual iteration on the Iterator which is provided.
static void	iteration(FeatureResultsIteration.Handler handler, org.geotools.data.FeatureResults features) A convienience method for obtaining a new iteration and calling iterate.
protected void	walker(org.geotools.feature.Feature feature) Perform the visitation of an individual Feature.
protected void	walker(org.geotools.data.FeatureResults results, org.geotools.data.FeatureReader reader) Perform the iterative behavior on the given collection.

Methods inherited from class java.lang.Object

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

Field Detail

handler

protected final FeatureResultsIteration.Handler handler

A callback handler for the iteration of the contents of a FeatureCollection.

Constructor Detail

FeatureResultsIteration

public FeatureResultsIteration(FeatureResultsIteration.Handler handler,
                               org.geotools.data.FeatureResults features)
                        throws java.lang.NullPointerException,
                               java.io.IOException

Create a new FeatureResultsIteration with the given handler and collection.

Parameters:

handler - The handler to perform operations on this iteration.

features - The collection to iterate over.

Throws:

java.lang.NullPointerException - If handler or collection are null.

java.io.IOException - DOCUMENT ME!

Method Detail

iteration

public static void iteration(FeatureResultsIteration.Handler handler,
                             org.geotools.data.FeatureResults features)
                      throws java.io.IOException

A convienience method for obtaining a new iteration and calling iterate.

Parameters:

handler - The handler to perform operations on this iteration.

features - The collection to iterate over.

Throws:

java.io.IOException - DOCUMENT ME!

iterate

public void iterate()
             throws java.io.IOException

Start the iteration.

Throws:

java.io.IOException - DOCUMENT ME!

walker

protected void walker(org.geotools.data.FeatureResults results,
                      org.geotools.data.FeatureReader reader)
               throws java.io.IOException

Perform the iterative behavior on the given collection. This will alert the handler with a handleFeatureCollection call, followed by an iterate(), followed by a handler.endFeatureCollection() call.

Parameters:

results - The collection to iterate upon.

reader - DOCUMENT ME!

Throws:

java.io.IOException - DOCUMENT ME!

org.geotools.data.DataSourceException - DOCUMENT ME!

iterate

protected void iterate(org.geotools.data.FeatureReader reader)
                throws java.io.IOException,
                       org.geotools.feature.IllegalAttributeException

Perform the actual iteration on the Iterator which is provided.

Parameters:

reader - The Iterator to iterate upon.

Throws:

java.io.IOException - DOCUMENT ME!

IllegalAttributeException - DOCUMENT ME!

walker

protected void walker(org.geotools.feature.Feature feature)

Perform the visitation of an individual Feature.

Parameters:

feature - The Feature to explore.

Throws:

java.lang.UnsupportedOperationException - DOCUMENT ME!