要素层正在使用从 RasterToVectorProcess 派生的要素集合获取空边界

Question

Null Pinter Exception 仅仅意味着它是因为值正在变得空。但是在使用 GeoTiff 等 API 的情况下，发现使用错误变得很烦人。

我的代码如下：

System.out.println("vectorization starts");

GridCoverage2D srcCoverage = new GeoTiffReader(new File("E:/output/ll_processed.TIFF")).read(new GeneralParameterValue[]{policy, gridsize, useJaiRead});

SimpleFeatureCollection fc = RasterToVectorProcess.process(srcCoverage, 3, cov.getEnvelope(), Collections.singletonList(0.0d), true, null);

System.out.println("process ends");
System.out.println("vectorization ends");
//MapContext map = new DefaultMapContext();
//map.setTitle("raster to vector conversion");
Style style = SLD.createPolygonStyle(Color.BLUE, Color.CYAN, 1.0f);
//map.addLayer(fc, style);
//map.getLayerBounds();
//JMapFrame.showMap(map);

MapContent mapContent= new MapContent();
mapContent.setTitle("Illegal Mining");
Layer layer = new FeatureLayer(fc, style,"VectorLayer");

//int boundary = 10;
// ReferencedEnvelope env2 = new  ReferencedEnvelope(srcCoverage.getEnvelope().getMinimum(0) - boundary, srcCoverage.getEnvelope().getMaximum(0) + boundary,
    //srcCoverage.getEnvelope().getMinimum(1) - boundary, srcCoverage.getEnvelope().getMaximum(1) + boundary, srcCoverage.getCoordinateReferenceSystem());

//mapContent.getViewport().setBounds(fc.getBounds());
Line 199 : if(layer.getBounds()!=null) // here the error is coming also tried with if(layer != null && layer.getBounds()!=null) 
 {
    mapContent.addLayer(layer);
}else{
    System.out.println("Layer bounds are null");
}
mapContent.getViewport().setCoordinateReferenceSystem(
        DefaultGeographicCRS.WGS84);

错误

at org.geotools.map.FeatureLayer.getBounds(FeatureLayer.java:199)

我正在尝试将 Tiff 转换为矢量图像，然后我想将其存储在磁盘上。

Answer 1

很可能，您的 featureSource 为 null，因为 geotools FeatureLayer class 方法 getBounds() 使用 featureSource 检索边界，但在构造函数中 FeatureLayer 不检查 featureSource 是否为 null.

featureSource 是 FeatureLayer 的构造函数的第一个参数。在您的情况下，这是变量 SimpleFeatureCollection fc.

很可能，方法 process.process 返回了 null，因此 fc 为空。

RasterToVectorProcess.java

中的细微变化

       //features.add(builder.buildFeature(null));
                //System.out.println("ignored");
                //add
                System.out.println("adding...");
                SimpleFeature feature = builder.buildFeature(null);
                ((Collection<SimpleFeature>) features).add(feature);

要素层正在使用从 RasterToVectorProcess 派生的要素集合获取空边界

Feature Layer is getting null bounds with featurecollection derived from RasterToVectorProcess

java

geotiff