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Add pagination for Layers that natively support it and simulated sorting for Layers that don't support sorting natively. Simulated pagination will be available when we switch to GeoTools 9.0
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+203
-13
lines changed

3 files changed

+203
-13
lines changed

‎src/main/groovy/geoscript/layer/Cursor.groovy

Lines changed: 34 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -5,6 +5,9 @@ import org.geotools.feature.FeatureIterator
55
import org.opengis.feature.simple.SimpleFeature
66
import org.opengis.feature.simple.SimpleFeatureType
77
import org.geotools.feature.FeatureCollection
8+
import org.geotools.data.store.MaxFeaturesIterator
9+
import org.geotools.data.sort.SortedFeatureIterator
10+
import org.opengis.filter.sort.SortBy
811

912
/**
1013
* A Cursor is a Iterator over a Feature objects.
@@ -30,32 +33,57 @@ class Cursor implements Iterator {
3033
* The GeoTools FeatureIterator
3134
*/
3235
private FeatureIterator<SimpleFeature> iter
33-
36+
3437
/**
3538
* The GeoTools FeatureCollection
3639
*/
3740
FeatureCollection<SimpleFeatureType, SimpleFeature> col
3841

42+
/**
43+
* A Map of options. Options can be: sort, start, max
44+
*/
45+
private Map options
46+
3947
/**
4048
* Create a new Cursor with a FeatureCollection
49+
* @param options A Map of options (sort, start, max)
4150
* @param col The GeoTools FeatureCollection
4251
*/
43-
Cursor(FeatureCollection<SimpleFeatureType, SimpleFeature> col) {
52+
Cursor(Map options = [:], FeatureCollection<SimpleFeatureType, SimpleFeature> col) {
53+
this.options = options
4454
this.col = col
45-
this.iter = col.features()
55+
createIterator()
4656
}
4757

4858
/**
4959
* Create a new Cursor with a FeatureCollection and a Layer
60+
* @param options A Map of options (sort, start, max)
5061
* @param col The GeoTools FeatureCollection
5162
* @param layer The Geoscript Layer
5263
*/
53-
Cursor(FeatureCollection<SimpleFeatureType, SimpleFeature> col, Layer layer) {
64+
Cursor(Map options = [:], FeatureCollection<SimpleFeatureType, SimpleFeature> col, Layer layer) {
65+
this.options = options
5466
this.col = col
55-
this.iter = col.features()
67+
createIterator()
5668
this.layer = layer
5769
}
5870

71+
/**
72+
* Create the FeatureIterator based on the FeatureCollection and options
73+
*/
74+
protected void createIterator() {
75+
this.iter = col.features()
76+
if (options.containsKey("sort")) {
77+
this.iter = new SortedFeatureIterator(this.iter, col.schema, options.sort as SortBy[], Integer.MAX_VALUE)
78+
}
79+
// This will work in GeoTools 9.0
80+
/*if (options.containsKey("start") && options.containsKey("max")) {
81+
long start = options.start as long
82+
long end = start + options.max as long
83+
this.iter = new MaxFeaturesIterator<SimpleFeature>(this.iter, start, end)
84+
}*/
85+
}
86+
5987
/**
6088
* Get the next Feature
6189
* @return The next Feature
@@ -110,6 +138,6 @@ class Cursor implements Iterator {
110138
* Reset and read the Features again.
111139
*/
112140
void reset() {
113-
iter = col.features()
141+
createIterator()
114142
}
115143
}

‎src/main/groovy/geoscript/layer/Layer.groovy

Lines changed: 44 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -87,7 +87,7 @@ class Layer {
8787
/**
8888
* The FilterFactory2 for creating Filters
8989
*/
90-
private final static FilterFactory2 filterFactory = org.geotools.factory.CommonFactoryFinder.getFilterFactory2(org.geotools.factory.GeoTools.getDefaultHints())
90+
protected final static FilterFactory2 filterFactory = org.geotools.factory.CommonFactoryFinder.getFilterFactory2(org.geotools.factory.GeoTools.getDefaultHints())
9191

9292
/**
9393
* Create a new Layer from a GeoTools FeatureSource
@@ -418,16 +418,55 @@ class Layer {
418418
return features
419419
}
420420

421+
/**
422+
* Get a Cursor over the Features of the Layer using named parameters.
423+
* @param options. The Map of named parameters can include:
424+
* <ul>
425+
* <li>filter = The Filter or Filter String to limit the Features. Defaults to null.</li>
426+
* <li>sort = A List of Lists that define the sort order [[Field or Field name, "ASC" or "DESC"],...]. Not all Layers
427+
* support sorting!</li>
428+
* <li>max= The maximum number of Features to include in the Cursor</li>
429+
* <li>start = The index of the record to start the cursor at. Together with maxFeatures this simulates paging.
430+
* Not all Layers support the start index and paging!</li>
431+
* </ul>
432+
* @return A Cursor
433+
*/
434+
Cursor getCursor(Map options) {
435+
getCursor(options.get("filter", null), options.get("sort", null),
436+
options.get("max",-1), options.get("start", -1))
437+
}
438+
421439
/**
422440
* Get a Cursor over the Features of the Layer.
423-
* @param filer The Filter or Filter String to limit the Features. Defaults to null.
441+
* @param filter The Filter or Filter String to limit the Features. Defaults to null.
424442
* @param sort A List of Lists that define the sort order [[Field or Field name, "ASC" or "DESC"],...]. Not all Layers
425443
* support sorting!
444+
* @param max The maximum number of Features to include in the Cursor
445+
* @param start The index of the record to start the cursor at. Together with maxFeatures this simulates paging.
446+
* Not all Layers support the start index and paging!
426447
* @return A Cursor
427448
*/
428-
Cursor getCursor(def filter = null, List sort = null) {
449+
Cursor getCursor(def filter = null, List sort = null, int max = -1, int start = -1) {
450+
Map cursorOptions = [:]
429451
Filter f = (filter == null) ? Filter.PASS : new Filter(filter)
430452
DefaultQuery q = new DefaultQuery(getName(), f.filter)
453+
if (max > -1) {
454+
q.maxFeatures = max
455+
}
456+
if (start > -1) {
457+
if (fs.queryCapabilities.offsetSupported) {
458+
q.startIndex = start
459+
} else {
460+
throw new UnsupportedOperationException("Start and max are not supported by this layer!");
461+
// This will work in GeoTools 9.0
462+
// cursorOptions.start = start
463+
// cursorOptions.max = max
464+
// Reset max features because the we will
465+
// be using the MaxFeaturesIterator in Cursor
466+
// and it needs all of the Features to simulate paging
467+
// q.maxFeatures = Integer.MAX_VALUE
468+
}
469+
}
431470
if (getProj()) {
432471
q.coordinateSystem = getProj().crs
433472
}
@@ -445,11 +484,11 @@ class Layer {
445484
if (fs.queryCapabilities.supportsSorting(sortByArray)) {
446485
q.sortBy = sortByArray
447486
} else {
448-
println "This Layer does not support sorting!"
487+
cursorOptions.sort = sortByArray
449488
}
450489
}
451490
def col = fs.getFeatures(q)
452-
return new Cursor(col, this)
491+
return new Cursor(cursorOptions, col, this)
453492
}
454493

455494
/**

‎src/test/groovy/geoscript/layer/LayerTestCase.groovy

Lines changed: 125 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -10,6 +10,7 @@ import geoscript.filter.Filter
1010
import geoscript.workspace.Memory
1111
import geoscript.geom.*
1212
import geoscript.workspace.Workspace
13+
import geoscript.workspace.H2
1314

1415
/**
1516
* The Layer UnitTest
@@ -358,31 +359,153 @@ class LayerTestCase {
358359
}
359360

360361
@Test void cursorSorting() {
362+
File f = new File("target/h2").absoluteFile
363+
if (f.exists()) {
364+
boolean deleted = f.deleteDir()
365+
}
366+
H2 h2 = new H2("facilities", "target/h2")
367+
Layer layer = h2.create('facilities',[new Field("geom","Point", "EPSG:2927"), new Field("name","string"), new Field("price","float")])
368+
layer.add(new Feature(["geom": new Point(111,-47), "name": "A", "price": 10], "house1"))
369+
layer.add(new Feature(["geom": new Point(112,-46), "name": "B", "price": 12], "house2"))
370+
layer.add(new Feature(["geom": new Point(113,-45), "name": "C", "price": 13], "house3"))
371+
layer.add(new Feature(["geom": new Point(113,-45), "name": "D", "price": 14], "house4"))
372+
layer.add(new Feature(["geom": new Point(113,-45), "name": "E", "price": 15], "house5"))
373+
layer.add(new Feature(["geom": new Point(113,-45), "name": "F", "price": 16], "house6"))
374+
375+
Cursor c = layer.getCursor(Filter.PASS, [["name","ASC"]])
376+
assertEquals "A", c.next()["name"]
377+
assertEquals "B", c.next()["name"]
378+
assertEquals "C", c.next()["name"]
379+
assertEquals "D", c.next()["name"]
380+
assertEquals "E", c.next()["name"]
381+
assertEquals "F", c.next()["name"]
382+
c.close()
383+
384+
c = layer.getCursor(Filter.PASS, ["name"])
385+
assertEquals "A", c.next()["name"]
386+
assertEquals "B", c.next()["name"]
387+
assertEquals "C", c.next()["name"]
388+
assertEquals "D", c.next()["name"]
389+
assertEquals "E", c.next()["name"]
390+
assertEquals "F", c.next()["name"]
391+
c.close()
392+
393+
c = layer.getCursor(Filter.PASS, [["name","DESC"]])
394+
assertEquals "F", c.next()["name"]
395+
assertEquals "E", c.next()["name"]
396+
assertEquals "D", c.next()["name"]
397+
assertEquals "C", c.next()["name"]
398+
assertEquals "B", c.next()["name"]
399+
assertEquals "A", c.next()["name"]
400+
c.close()
401+
402+
// Named Parameters
403+
c = layer.getCursor(filter: "price >= 14.0", sort: [["price", "DESC"]])
404+
assertTrue c.hasNext()
405+
assertEquals "F", c.next()["name"]
406+
assertEquals "E", c.next()["name"]
407+
assertEquals "D", c.next()["name"]
408+
assertFalse c.hasNext()
409+
c.close()
410+
411+
h2.close()
412+
}
413+
414+
@Test void cursorSortingAndPagingWithUnsupportedLayer() {
361415
Schema s = new Schema("facilities", [new Field("geom","Point", "EPSG:2927"), new Field("name","string"), new Field("price","float")])
362416
Layer layer = new Layer("facilities", s)
363417
layer.add(new Feature([new Point(111,-47), "A", 10], "house1", s))
364418
layer.add(new Feature([new Point(112,-46), "B", 12], "house2", s))
365419
layer.add(new Feature([new Point(113,-45), "C", 11], "house3", s))
420+
layer.add(new Feature([new Point(113,-44), "D", 15], "house4", s))
366421

422+
// Sort ascending explicitly
367423
Cursor c = layer.getCursor(Filter.PASS, [["name","ASC"]])
368424
assertEquals "A", c.next()["name"]
369425
assertEquals "B", c.next()["name"]
370426
assertEquals "C", c.next()["name"]
427+
assertEquals "D", c.next()["name"]
428+
assertFalse c.hasNext()
371429
c.close()
372430

431+
// Sort ascending implicitly
373432
c = layer.getCursor(Filter.PASS, ["name"])
374433
assertEquals "A", c.next()["name"]
375434
assertEquals "B", c.next()["name"]
376435
assertEquals "C", c.next()["name"]
436+
assertEquals "D", c.next()["name"]
437+
assertFalse c.hasNext()
377438
c.close()
378439

379-
// @TODO MemoryDataStore doesn't actually sort!
380-
/*c = layer.getCursor(Filter.PASS, [["name","DESC"]])
440+
// Sort descending
441+
c = layer.getCursor(Filter.PASS, [["name","DESC"]])
442+
assertEquals "D", c.next()["name"]
381443
assertEquals "C", c.next()["name"]
382444
assertEquals "B", c.next()["name"]
383445
assertEquals "A", c.next()["name"]
446+
assertFalse c.hasNext()
447+
c.close()
448+
449+
// Page (will work with GeoTools 9.0)
450+
/*c = layer.getCursor(start:0, max:2)
451+
assertEquals "A", c.next()["name"]
452+
assertEquals "B", c.next()["name"]
453+
assertFalse c.hasNext()
454+
c.close()
455+
c = layer.getCursor(start:2, max:2)
456+
assertEquals "C", c.next()["name"]
457+
assertEquals "D", c.next()["name"]
458+
assertFalse c.hasNext()
459+
c.close()
460+
c = layer.getCursor("price > 10", [["price", "DESC"]], 2, 1)
461+
assertEquals "B", c.next()["name"]
462+
assertEquals "C", c.next()["name"]
463+
assertFalse c.hasNext()
384464
c.close()*/
385465
}
386466

467+
@Test void cursorPaging() {
468+
File f = new File("target/h2").absoluteFile
469+
if (f.exists()) {
470+
boolean deleted = f.deleteDir()
471+
}
472+
H2 h2 = new H2("facilities", "target/h2")
473+
Layer layer = h2.create('facilities',[new Field("geom","Point", "EPSG:2927"), new Field("name","string"), new Field("price","float")])
474+
layer.add(new Feature(["geom": new Point(111,-47), "name": "A", "price": 10], "house1"))
475+
layer.add(new Feature(["geom": new Point(112,-46), "name": "B", "price": 12], "house2"))
476+
layer.add(new Feature(["geom": new Point(113,-45), "name": "C", "price": 13], "house3"))
477+
layer.add(new Feature(["geom": new Point(113,-45), "name": "D", "price": 14], "house4"))
478+
layer.add(new Feature(["geom": new Point(113,-45), "name": "E", "price": 15], "house5"))
479+
layer.add(new Feature(["geom": new Point(113,-45), "name": "F", "price": 16], "house6"))
480+
481+
Cursor c = layer.getCursor(Filter.PASS, [["name","ASC"]], 2, 0)
482+
assertEquals "A", c.next()["name"]
483+
assertEquals "B", c.next()["name"]
484+
assertFalse c.hasNext()
485+
c.close()
486+
487+
c = layer.getCursor(Filter.PASS, [["name","ASC"]], 2, 2)
488+
assertEquals "C", c.next()["name"]
489+
assertEquals "D", c.next()["name"]
490+
assertFalse c.hasNext()
491+
c.close()
492+
493+
c = layer.getCursor(Filter.PASS, [["name","ASC"]], 2, 4)
494+
assertEquals "E", c.next()["name"]
495+
assertEquals "F", c.next()["name"]
496+
assertFalse c.hasNext()
497+
c.close()
498+
499+
// Named parameters
500+
c = layer.getCursor(start: 0, max: 4)
501+
assertEquals "A", c.next()["name"]
502+
assertEquals "B", c.next()["name"]
503+
assertEquals "C", c.next()["name"]
504+
assertEquals "D", c.next()["name"]
505+
c.close()
506+
507+
h2.close()
508+
}
509+
387510
}
388511

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