Plot Longitude and Latitudes on Map using GeoTools – How to Tutorial

geotoolsjavalatitude longitude

I am new to geotools and i find bit difficult to plot a point using the latitude and longitude values. can any one help me out to solve my problem.
I tried the following code but not helpful.By quickstart i can able to pass a shapefile and getting the map but unable to plot the lat long values on it.

   SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();

         b.setName( "MyFeatureType" );
          b.setCRS( DefaultGeographicCRS.WGS84 );
          b.add( "location", Point.class ); 
          //building  the type
          final SimpleFeatureType TYPE = b.buildFeatureType();

        SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
        GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory(); 
        Point point = geometryFactory.createPoint(new Coordinate(longitude, latitude));
          featureBuilder.add(point);
          SimpleFeature feature = featureBuilder.buildFeature( "fid.1" );
          DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("internal",TYPE);
          featureCollection.add(feature);

Adding to map:

List a=new ArrayList();
a.add(-155.2792);
a.add(67.3623); 
double longitude=(Double) a.get(0);
double latitude=(Double)a.get(0); 
File file = JFileDataStoreChooser.showOpenFile("shp", null); 
if (file == null) { return; } 
FileDataStore store = FileDataStoreFinder.getDataStore(file); 
SimpleFeatureSource featureSource = store.getFeatureSource(); 
MapContext map = new DefaultMapContext(); 
map.setTitle("Show Map"); 




Layer layer = new FeatureLayer(featureSource, null);
        map.addLayer(layer);
    map.addLayer(featureSource, null); 
    JMapFrame.showMap(map);

Best Answer

There are three distinct steps here, 1st make the point (which you seem to be able to do), 2nd add it to a layer with a style, 3rd add that to the map. This does the first 2 steps:

static Layer addPoint(double latitude, double longitude) {
    SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();

    b.setName("MyFeatureType");
    b.setCRS(DefaultGeographicCRS.WGS84);
    b.add("location", Point.class);
    // building the type
    final SimpleFeatureType TYPE = b.buildFeatureType();

    SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
    GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
    Point point = geometryFactory.createPoint(new Coordinate( latitude, longitude));
    featureBuilder.add(point);
    SimpleFeature feature = featureBuilder.buildFeature(null);
    DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("internal", TYPE);
    featureCollection.add(feature);
    Style style = SLD.createSimpleStyle(TYPE,Color.red);

    Layer layer = new FeatureLayer(featureCollection, style);
    return layer;
  }

then add this to the QuickStart:

  Layer pLayer = addPoint(-155.27,67.3623);
  map.addLayer(pLayer);

which creates a small red point in Alaska.

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[GIS] locating latitude-longitude point in a piste-map with matrix transforms

If the image is in the least realistic--and it appears to be--then it represents a projection from a portion of Euclidean three-space onto a portion of two-space. We cannot expect this projection to have a nice mathematical formula, because it is likely the artist has introduced irrregular small distortions, but we can expect its formula to somewhat approximate formulas for such projections. These formulas tend to be linear or projective and they also tend to be simpler when Cartesian coordinates are used.

Therefore, what you should consider doing at the outset is this:

Convert all (lat, lon, elevation) values to geocentric (x, y, z) values.
Associated with each (x, y, z) value is a pair of image coordinates (u, v). We probably lose little by estimating u and v independently of each other, which reduces the problem to one of interpolating samples of a scalar function. The previous considerations suggest that you seek interpolating functions that locally are of the form
```
u = a x + b y + c z + d
```
(linear) or even
```
u = (a x + b y + c z + d) / (a' x + b' y + c' z + 1)
```
(projective) and similarly for v. This reduces the problem to one of performing an interpolation in three dimensions, which is sufficiently routine to give you access to a large body of methods and software.

Alternatively, you might consider triangulating the (x,y,z) points and interpolating their associated (u,v) values separately across the triangles; even a linear interpolation across each triangular face could do a pretty good job. This is a 3D analog of what ESRI's 3D Analyst does in two dimensions with TINs.

Please note, though, that unless you have the elevation of a given location, you cannot hope to plot it accurately on this map: changing the elevation will create a nearly vertical line on the map, whence your location could be plotted practically anywhere along this line. With considerable work you could solve this problem for points on the ground by first digitizing the evident discontinuities in the inverse projection--that is, representing the outlines of mountain ridges as polylines--and constructing a local inverse interpolator (respecting these breaklines) that associates to each (u,v) on the image a location (x,y,z) in the world. You could exploit this to identify which point along any vertical line has a (lat,lon) close to the one you started with.

[GIS] Creating point in shapefile from latitude/longitude using GeoTools

In your code, you miss to define a feature type: In GeoTools (and not only), you will first need to define the structure of your data, ie the Feature type (~ schema). For this you have to use SimpleFeatureTypeBuilder that will help to build the feature type, afterwhat you will be able to construct properly the SimpleFeatureBuilder based on the featuretype you defined before (the TYPE argument in your code)

Create the Simple Feature Type (structure of your data):

SimpleFeatureTypeBuilder b = new SimpleFeatureTypeBuilder();

//set the name
b.setName( "MyFeatureType" );

//add a geometry property
b.setCRS( DefaultGeographicCRS.WGS84 ); // set crs first
b.add( "location", Point.class ); // then add geometry

//build the type
final SimpleFeatureType TYPE = b.buildFeatureType();

Create the feature(s) using the feature type previously defined

SimpleFeatureBuilder featureBuilder = new SimpleFeatureBuilder(TYPE);
GeometryFactory geometryFactory = JTSFactoryFinder.getGeometryFactory();
Point point = geometryFactory.createPoint(new Coordinate(longitude, latitude));
featureBuilder.add(point);
SimpleFeature feature = featureBuilder.buildFeature( "fid.1" ); // build the 1st feature

Next step, you can create a feature collection, using the feature(s) you defined before:

DefaultFeatureCollection featureCollection = new DefaultFeatureCollection("internal",TYPE);
featureCollection.add(feature); //Add feature 1
// Add feature 2, 3, etc

I recommend you to follow examples from http://docs.geotools.org/latest/userguide/library/main This will also help to understand how geospatial data is structured in Geotools

For the plotting part, i suggest you to familiarize with the geotools rendering module: http://docs.geotools.org/latest/userguide/library/render/map.html.

Best Answer

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[GIS] Creating point in shapefile from latitude/longitude using GeoTools

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