[GEOS-9014] Fixes layer iteration when generating kml files for download

Factor out Sequence interface, replace with Iterator and fix GeneratorIterator

Starting test, rename layerIterator

Fixed and working layergroup kml test

Refactor kml.sequence package and classes, rename kml.iterator

comment out print line

src/community/kmlppio/src/main/java/org/geoserver/wps/ppio/KMLPPIO.java

@@ -24,8 +24,8 @@
 import org.geoserver.kml.KMLMapOutputFormat;
 import org.geoserver.kml.KmlEncodingContext;
 import org.geoserver.kml.decorator.KmlDecoratorFactory.KmlDecorator;
-import org.geoserver.kml.sequence.SequenceList;
-import org.geoserver.kml.sequence.WFSFeatureSequenceFactory;
+import org.geoserver.kml.iterator.IteratorList;
+import org.geoserver.kml.iterator.WFSFeatureIteratorFactory;
 import org.geoserver.platform.ServiceException;
 import org.geoserver.wfs.WFSInfo;
 import org.geotools.data.collection.ListFeatureCollection;
@@ -197,7 +197,7 @@ public void encode(Object obj, OutputStream os) throws Exception {
             // create the streaming features
             context.setCurrentFeatureCollection(fc);
             List<Feature> features =
-                    new SequenceList<Feature>(new WFSFeatureSequenceFactory(context));
+                    new IteratorList<Feature>(new WFSFeatureIteratorFactory(context));
             context.addFeatures(folder, features);
         }
 

src/kml/src/main/java/org/geoserver/kml/KmlEncodingContext.java

@@ -19,7 +19,7 @@
 import org.geoserver.config.ServiceInfo;
 import org.geoserver.kml.decorator.KmlDecoratorFactory;
 import org.geoserver.kml.decorator.KmlDecoratorFactory.KmlDecorator;
-import org.geoserver.kml.sequence.CompositeList;
+import org.geoserver.kml.iterator.CompositeList;
 import org.geoserver.kml.utils.LookAtOptions;
 import org.geoserver.ows.util.KvpUtils;
 import org.geoserver.platform.GeoServerExtensions;

src/kml/src/main/java/org/geoserver/kml/WFSKMLOutputFormat.java

@@ -17,8 +17,8 @@
 import org.geoserver.config.GeoServer;
 import org.geoserver.config.ServiceInfo;
 import org.geoserver.kml.decorator.KmlDecoratorFactory.KmlDecorator;
-import org.geoserver.kml.sequence.SequenceList;
-import org.geoserver.kml.sequence.WFSFeatureSequenceFactory;
+import org.geoserver.kml.iterator.IteratorList;
+import org.geoserver.kml.iterator.WFSFeatureIteratorFactory;
 import org.geoserver.platform.Operation;
 import org.geoserver.platform.ServiceException;
 import org.geoserver.wfs.WFSGetFeatureOutputFormat;
@@ -105,7 +105,7 @@ protected void write(
             // create the streaming features
             context.setCurrentFeatureCollection(fc);
             List<Feature> features =
-                    new SequenceList<Feature>(new WFSFeatureSequenceFactory(context));
+                    new IteratorList<Feature>(new WFSFeatureIteratorFactory(context));
             context.addFeatures(folder, features);
         }
 

src/kml/src/main/java/org/geoserver/kml/builder/StreamingKMLBuilder.java

@@ -11,9 +11,9 @@
 import java.util.List;
 import org.geoserver.kml.KmlEncodingContext;
 import org.geoserver.kml.decorator.KmlDecoratorFactory.KmlDecorator;
-import org.geoserver.kml.sequence.PlainFolderSequenceFactory;
-import org.geoserver.kml.sequence.SequenceFactory;
-import org.geoserver.kml.sequence.SequenceList;
+import org.geoserver.kml.iterator.IteratorFactory;
+import org.geoserver.kml.iterator.IteratorList;
+import org.geoserver.kml.iterator.PlainFolderIteratorFactory;
 import org.geoserver.platform.ServiceException;
 
 /**
@@ -49,8 +49,8 @@ public Kml buildKMLDocument(KmlEncodingContext context) {
 
         // create a generator that will generate a folder and feature dumps/ground overlays for each
         // layer
-        SequenceFactory<Feature> generatorFactory = new PlainFolderSequenceFactory(context);
-        SequenceList<Feature> folders = new SequenceList<Feature>(generatorFactory);
+        IteratorFactory<Feature> generatorFactory = new PlainFolderIteratorFactory(context);
+        IteratorList<Feature> folders = new IteratorList<Feature>(generatorFactory);
         context.addFeatures(document, folders);
 
         return kml;

src/kml/src/main/java/org/geoserver/kml/sequence/AbstractFolderSequenceFactory.java → src/kml/src/main/java/org/geoserver/kml/iterator/AbstractFolderIteratorFactory.java

@@ -3,10 +3,11 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import de.micromata.opengis.kml.v_2_2_0.Feature;
 import de.micromata.opengis.kml.v_2_2_0.Folder;
+import java.util.Iterator;
 import java.util.List;
 import org.geoserver.kml.KmlEncodingContext;
 import org.geoserver.kml.decorator.KmlDecoratorFactory.KmlDecorator;
@@ -19,35 +20,32 @@
 import org.geotools.map.Layer;
 
 /**
- * Base class for sequences that create one folder per layer
+ * Base class for iterators that create one folder per layer
  *
  * @author Andrea Aime - GeoSolutions
  */
-public abstract class AbstractFolderSequenceFactory implements SequenceFactory<Feature> {
+public abstract class AbstractFolderIteratorFactory implements IteratorFactory<Feature> {
 
     protected KmlEncodingContext context;
 
     protected List<KmlDecorator> decorators;
 
-    public AbstractFolderSequenceFactory(KmlEncodingContext context) {
+    public AbstractFolderIteratorFactory(KmlEncodingContext context) {
         this.context = context;
         this.decorators = context.getDecoratorsForClass(Folder.class);
     }
 
-    public abstract class AbstractFolderGenerator implements Sequence<Feature> {
-        protected int i = 0;
-
-        protected int size;
+    public abstract class AbstractFolderGenerator implements Iterator<Feature> {
+        Iterator layerIterator;
 
         public AbstractFolderGenerator() {
-            this.size = context.getMapContent().layers().size();
+            this.layerIterator = context.getMapContent().layers().iterator();
         }
 
         @Override
         public Feature next() {
-            while (i < size) {
-                List<Layer> layers = context.getMapContent().layers();
-                Layer layer = layers.get(i++);
+            while (hasNext()) {
+                Layer layer = (Layer) layerIterator.next();
                 context.setCurrentLayer(layer);
 
                 // setup the folder and let it be decorated
@@ -94,6 +92,11 @@ public Feature next() {
             return null;
         }
 
+        @Override
+        public boolean hasNext() {
+            return layerIterator.hasNext();
+        }
+
         /**
          * Encodes the actual contents of the folder, besides the one generated by decorators
          *

src/kml/src/main/java/org/geoserver/kml/sequence/CompositeList.java → src/kml/src/main/java/org/geoserver/kml/iterator/CompositeList.java

@@ -3,7 +3,7 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import java.util.AbstractList;
 import java.util.Iterator;

src/kml/src/main/java/org/geoserver/kml/sequence/FeatureSequenceFactory.java → src/kml/src/main/java/org/geoserver/kml/iterator/FeatureIteratorFactory.java

@@ -3,11 +3,12 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import de.micromata.opengis.kml.v_2_2_0.Feature;
 import de.micromata.opengis.kml.v_2_2_0.Placemark;
 import java.util.EmptyStackException;
+import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.geoserver.kml.KmlEncodingContext;
@@ -27,11 +28,11 @@
 import org.opengis.feature.simple.SimpleFeatureType;
 
 /**
- * Creates a sequence of Placemark objects mapping the vector contents of a layer
+ * Creates a iterator of Placemark objects mapping the vector contents of a layer
  *
  * @author Andrea Aime - GeoSolutions
  */
-public class FeatureSequenceFactory implements SequenceFactory<Feature> {
+public class FeatureIteratorFactory implements IteratorFactory<Feature> {
 
     static final String OUTPUT_MODE = "kmlOutputMode";
 
@@ -47,7 +48,7 @@ public class FeatureSequenceFactory implements SequenceFactory<Feature> {
 
     private boolean hasActiveRules;
 
-    public FeatureSequenceFactory(KmlEncodingContext context, FeatureLayer layer) {
+    public FeatureIteratorFactory(KmlEncodingContext context, FeatureLayer layer) {
         this.context = context;
         this.features = context.getCurrentFeatureCollection();
         WMSMapContent mapContent = context.getMapContent();
@@ -88,11 +89,11 @@ private Style getSimplifiedStyle(WMSMapContent mc, Layer layer) {
     }
 
     @Override
-    public Sequence<Feature> newSequence() {
+    public Iterator<Feature> newIterator() {
         return new FeatureGenerator(hasActiveRules ? context.openIterator(features) : null);
     }
 
-    public class FeatureGenerator implements Sequence<Feature> {
+    public class FeatureGenerator implements Iterator<Feature> {
 
         private FeatureIterator fi;
 
@@ -159,6 +160,11 @@ public Feature next() {
             return null;
         }
 
+        @Override
+        public boolean hasNext() {
+            return fi.hasNext();
+        }
+
         private List<Symbolizer> getSymbolizers(Style style, SimpleFeature sf) {
             SymbolizerCollector collector = new SymbolizerCollector(sf);
             style.accept(collector);

src/kml/src/main/java/org/geoserver/kml/sequence/SequenceFactory.java → src/kml/src/main/java/org/geoserver/kml/iterator/IteratorFactory.java

@@ -3,15 +3,17 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
+
+import java.util.Iterator;
 
 /**
- * Builds a new Sequence
+ * Builds a new Iterator
  *
  * @author Andrea Aime - GeoSolutions
  * @param <T>
  */
-public interface SequenceFactory<T> {
+public interface IteratorFactory<T> {
 
-    Sequence<T> newSequence();
+    Iterator<T> newIterator();
 }

src/kml/src/main/java/org/geoserver/kml/sequence/SequenceList.java → src/kml/src/main/java/org/geoserver/kml/iterator/IteratorList.java

@@ -3,7 +3,7 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import java.util.AbstractList;
 import java.util.Iterator;
@@ -15,22 +15,19 @@
  * @author Andrea Aime - GeoSolutions
  * @param <T>
  */
-public class SequenceList<T> extends AbstractList<T> {
+public class IteratorList<T> extends AbstractList<T> {
 
     public class GeneratorIterator implements Iterator<T> {
 
-        private Sequence<T> generator;
+        private Iterator<T> generator;
 
-        private T item;
-
-        public GeneratorIterator(Sequence<T> generator) {
+        public GeneratorIterator(Iterator<T> generator) {
             this.generator = generator;
-            this.item = generator.next();
         }
 
         @Override
         public boolean hasNext() {
-            return item != null;
+            return generator.hasNext();
         }
 
         @Override
@@ -39,9 +36,7 @@ public T next() {
                 throw new NoSuchElementException();
             }
 
-            T next = this.item;
-            this.item = generator.next();
-            return next;
+            return generator.next();
         }
 
         @Override
@@ -50,15 +45,15 @@ public void remove() {
         }
     }
 
-    SequenceFactory<T> generatorFactory;
+    IteratorFactory<T> generatorFactory;
 
-    public SequenceList(SequenceFactory<T> generatorFactory) {
+    public IteratorList(IteratorFactory<T> generatorFactory) {
         this.generatorFactory = generatorFactory;
     }
 
     @Override
     public Iterator iterator() {
-        return new GeneratorIterator(generatorFactory.newSequence());
+        return new GeneratorIterator(generatorFactory.newIterator());
     }
 
     @Override

src/kml/src/main/java/org/geoserver/kml/sequence/KMLCentroidFeatureCollection.java → src/kml/src/main/java/org/geoserver/kml/iterator/KMLCentroidFeatureCollection.java

@@ -3,7 +3,7 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import java.util.NoSuchElementException;
 import org.geoserver.kml.KmlEncodingContext;

src/kml/src/main/java/org/geoserver/kml/sequence/PlainFolderSequenceFactory.java → src/kml/src/main/java/org/geoserver/kml/iterator/PlainFolderIteratorFactory.java

@@ -3,14 +3,15 @@
  * This code is licensed under the GPL 2.0 license, available at the root
  * application directory.
  */
-package org.geoserver.kml.sequence;
+package org.geoserver.kml.iterator;
 
 import de.micromata.opengis.kml.v_2_2_0.Feature;
 import de.micromata.opengis.kml.v_2_2_0.Folder;
 import de.micromata.opengis.kml.v_2_2_0.GroundOverlay;
 import de.micromata.opengis.kml.v_2_2_0.Icon;
 import de.micromata.opengis.kml.v_2_2_0.LatLonBox;
 import de.micromata.opengis.kml.v_2_2_0.ViewRefreshMode;
+import java.util.Iterator;
 import java.util.List;
 import org.geoserver.kml.KmlEncodingContext;
 import org.geoserver.platform.ServiceException;
@@ -24,32 +25,32 @@
 import org.geotools.referencing.crs.DefaultGeographicCRS;
 
 /**
- * Creates a sequence of folders mapping the layers in the map content, using either kml dumps or
+ * Creates an iterator of folders mapping the layers in the map content, using either kml dumps or
  * ground overlays (the classic approach, that is)
  *
  * @author Andrea Aime - GeoSolutions
  */
-public class PlainFolderSequenceFactory extends AbstractFolderSequenceFactory {
+public class PlainFolderIteratorFactory extends AbstractFolderIteratorFactory {
 
-    public PlainFolderSequenceFactory(KmlEncodingContext context) {
+    public PlainFolderIteratorFactory(KmlEncodingContext context) {
         super(context);
     }
 
     @Override
-    public Sequence<Feature> newSequence() {
+    public Iterator<Feature> newIterator() {
         return new PlainFolderGenerator();
     }
 
     public class PlainFolderGenerator extends AbstractFolderGenerator {
 
         protected void encodeFolderContents(Layer layer, Folder folder) {
-            // now encode the contents (dynamic bit, it may use the Sequence construct)
+            // now encode the contents (dynamic bit, it may use the Iterator construct)
             if (layer instanceof FeatureLayer) {
                 // do we use a KML placemark dump, or a ground overlay?
                 if (useVectorOutput(context)) {
                     List<Feature> features =
-                            new SequenceList<Feature>(
-                                    new FeatureSequenceFactory(context, (FeatureLayer) layer));
+                            new IteratorList<Feature>(
+                                    new FeatureIteratorFactory(context, (FeatureLayer) layer));
                     context.addFeatures(folder, features);
                 } else {
                     addGroundOverlay(folder, layer);
@@ -80,7 +81,7 @@ private void addFeatureCentroids(Layer layer, Folder folder) {
             FeatureLayer centroidsLayer =
                     new FeatureLayer(centroids, layer.getStyle(), layer.getTitle());
             List<Feature> features =
-                    new SequenceList<Feature>(new FeatureSequenceFactory(context, centroidsLayer));
+                    new IteratorList<Feature>(new FeatureIteratorFactory(context, centroidsLayer));
             context.addFeatures(folder, features);
         }