[GIS] Well-known text (wkt) validator

validationwell-known-text

Is there anything like http://jsonlint.com or http://geojsonlint.com for WKT? How can I validate a complex WKT string, say e.g. a Multipolygon?

Best Answer

One possible WKT validator can be PostGIS or a whatever spatial DBMS you like. For instance:

SELECT ST_GeomFromText('POINT(-71.064544 42.28787)');

is executed successfully, because POINT(-71.064544 42.28787) is a valid WKT representation. Instead:

SELECT ST_GeomFromText('POINT(-71.064544, 42.28787)');

returns:

ERROR: parse error - invalid geometry HINT: "POINT(-71.064544, " <-- parse error at position 18 within geometry *** Error ***

ERROR: parse error - invalid geometry SQL state: XX000 Hint: "POINT(-71.064544, " <-- parse error at position 18 within geometry

because POINT(-71.064544, 42.28787) is not a valid WKT. Hope this helps.

Related Solutions

[GIS] Parsing large GeoJson geometry to WKT

At the moment I got it working like this. But i have the feeling it's not the best way to do it.

If anybody have a better way to do it, please say it.

I'm using gson 2.3.1

InputStream in = new FileInputStream(context.getExternalFilesDir(null).getPath() + "/" + jsonDatabaseFile); 
JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8"))

;

                        if (tag.equals("geometry")) {                       
                            reader.beginObject();   
                            while (reader.hasNext()) {  
                                tag = reader.nextName();    
                                // geometry type
                                // ----------------------------------------------------------------------------------
                                if (tag.equals("type")) {                       
                                    type = reader.nextString();
                                }
                                // geometry coordinates
                                // ----------------------------------------------------------------------------------
                                else if (tag.equals("coordinates")) {   
                                    coordinates.append("(");
                                    reader.beginArray();                                    
                                    while (reader.hasNext()) {
                                        coordinates.append("(");
                                        reader.beginArray();                                            
                                        while (reader.hasNext()) {  
                                            coordinates.append("(");
                                            reader.beginArray();                                                
                                            while (reader.hasNext()) {  
                                                reader.beginArray();        
                                                while (reader.hasNext()) {  
                                                    if(!even){                                                  
                                                        coordinates.append((reader.nextString()));
                                                        coordinates.append(" ");
                                                        even = true;
                                                    }
                                                    else{
                                                        coordinates.append((reader.nextString()));                                                  
                                                        coordinates.append(",");
                                                        even = false;
                                                    }
                                                }                                           
                                                reader.endArray();                                              
                                            }
                                            reader.endArray();
                                            coordinates.deleteCharAt(coordinates.length() -1);
                                            coordinates.append("),");               
                                        }
                                        reader.endArray();
                                        coordinates.deleteCharAt(coordinates.length() -1);
                                        coordinates.append("),");                       
                                    }
                                    coordinates.deleteCharAt(coordinates.length() -1);
                                    reader.endArray();
                                }
                                else {
                                    reader.skipValue(); 
                                }                               
                            }                               
                            reader.endObject(); 
                            coordinates.append(")");                                                    
                        }

    (...)
    wkt = type.toUpperCase() + coordinates;

Best Answer

Related Solutions

[GIS] Parsing large GeoJson geometry to WKT

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