英文:
java.lang.NullPointerException by Geocoder with GeoTools and Shapefiles
问题
我是新手，尝试使用Geotools中的Reverse Geocode脚本。但我总是收到java.lang.NullPointerException错误。有人能帮我吗？
> 在线程 "main" 中的异常 java.lang.NullPointerException
> 位于 org.locationtech.jts.geom.Envelope.intersects(Envelope.java:528)
> 在 org.locationtech.jts.index.strtree.STRtree$3.intersects(STRtree.java:108)
> 在 org.locationtech.jts.index.strtree.AbstractSTRtree.query(AbstractSTRtree.java:256)
> 在 org.locationtech.jts.index.strtree.STRtree.query(STRtree.java:205)
> 在 org.geotools.data.collection.SpatialIndexFeatureCollection.subCollection(SpatialIndexFeatureCollection.java:152)
> 在 com.company.SimpleGeoCoder.lookup(SimpleGeoCoder.java:53)
> 在 com.company.Main.main(Main.java:60)
public class Main {
public static void main(String[] args) throws IOException {
GeometryFactory gf = new GeometryFactory();
SimpleGeoCoder geocoder = new SimpleGeoCoder();
Point london = gf.createPoint(new Coordinate(0.0, 51.0));
SimpleFeatureCollection features = geocoder.lookup(london);
SimpleFeatureIterator itr = features.features();
try {
while (itr.hasNext()) {
SimpleFeature f = itr.next();
System.out.println(f.getAttribute("NAME"));
}
} finally {
itr.close();
}
}
}
public class SimpleGeoCoder {
SpatialIndexFeatureCollection countries;
final static FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
final static public String countryFile = "countries.shp";
public SimpleGeoCoder() throws IOException {
URL countryURL = URLs.fileToUrl(new File(this.countryFile));
HashMap<String, Object> params = new HashMap<>();
params.put("url", countryURL);
DataStore ds = DataStoreFinder.getDataStore(params);
if (ds == null) {
throw new IOException("couldn't open " + params.get("url"));
}
Name name = ds.getNames().get(0);
this.countries = new SpatialIndexFeatureCollection(ds.getFeatureSource(name).getFeatures());
}
public SimpleFeatureCollection lookup(Point p) {
Filter f = ff.contains(ff.property("the_geom"), ff.literal(p));
return this.countries.subCollection(f);
}
}
英文:
I am new to java and try to use a Reverse Geocode Script from Geotools. But I always get a java.lang.NullPointerException. Can someone help me?
> Exception in thread "main" java.lang.NullPointerException at
> org.locationtech.jts.geom.Envelope.intersects(Envelope.java:528) at
> org.locationtech.jts.index.strtree.STRtree$3.intersects(STRtree.java:108)
> at
> org.locationtech.jts.index.strtree.AbstractSTRtree.query(AbstractSTRtree.java:256)
> at org.locationtech.jts.index.strtree.STRtree.query(STRtree.java:205)
> at
> org.geotools.data.collection.SpatialIndexFeatureCollection.subCollection(SpatialIndexFeatureCollection.java:152)
> at com.company.SimpleGeoCoder.lookup(SimpleGeoCoder.java:53) at
> com.company.Main.main(Main.java:60)
public class Main {
public static void main(String[] args) throws IOException {
GeometryFactory gf = new GeometryFactory();
SimpleGeoCoder geocoder = new SimpleGeoCoder();
Point london = gf.createPoint(new Coordinate(0.0, 51.0));
SimpleFeatureCollection features = geocoder.lookup(london);
SimpleFeatureIterator itr = features.features();
try {
while (itr.hasNext()) {
SimpleFeature f = itr.next();
System.out.println(f.getAttribute("NAME"));
}
} finally {
itr.close();
}
}
}
public class SimpleGeoCoder {
SpatialIndexFeatureCollection countries;
final static FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2();
final static public String countryFile = "countries.shp";
public SimpleGeoCoder() throws IOException {
URL countryURL = URLs.fileToUrl(new File(this.countryFile));
HashMap<String, Object> params = new HashMap<>();
params.put("url", countryURL);
DataStore ds = DataStoreFinder.getDataStore(params);
if (ds == null) {
throw new IOException("couldn't open " + params.get("url"));
}
Name name = ds.getNames().get(0);
this.countries = new SpatialIndexFeatureCollection(ds.getFeatureSource(name).getFeatures());
}
public SimpleFeatureCollection lookup(Point p) {
Filter f = ff.contains(ff.property("the_geom"), ff.literal(p));
return this.countries.subCollection(f);
}
}
答案1
得分: 0
可能你使用了这个Gist的示例（https://gitlab.com/-/snippets/15776），并且你需要更新一些导入语句才能使它工作。
将以下代码段：
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;
替换为：
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.Point;
虽然很简单，但我花了3个小时才找到如何修复它。
英文:
Most probably you used the example from this gist (https://gitlab.com/-/snippets/15776) and yon need to update some imports to make it work
Replace
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.Point;
with
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.Point;
It was so simple, but it took me 3 hours to find out how to fix it.
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