B4J Library ShapeFile Reader

A wrap of this library;

GitHub - diwi/diewald_shapeFileReader: java library for reading ESRI-shapeFiles

java library for reading ESRI-shapeFiles. Contribute to diwi/diewald_shapeFileReader development by creating an account on GitHub.

github.com

Should work on B4A as well (but not tested) since its pure Java.

Zip contains library, some test Shapefiles as well as a B4J project with the code below.

Super simple;

Dim shp As ShapeFileReader
    shp.Initialize("C:\Temp\ShapeFiles","ne_110m_admin_0_countries")
    'shp.Initialize("C:\Temp\ShapeFiles","ne_110m_populated_places")
    'shp.Initialize("C:\Temp\ShapeFiles","ne_110m_rivers_lake_centerlines")
        
    Log(shp.ShapeType)
    Log(shp.FieldCount)
    Log(shp.ShapeCount)
    Log(shp.BoundingBox)
    
    ' Log attribute name, length and type for the first field
    Log(shp.getFieldName(0))
    Log(shp.getFieldLength(0))   
    Log(shp.getFieldType(0))
    
    ' Log first attribute record
    Log(shp.getRecord(0))
    
    ' Shape or Geometry is an list of lists of list
    ' the list is the list of parts (becuase polygons and polylines can consiste of multiple parts)
    ' within each part is a list of coordinates where coordinates are x,y,z,m
    ' NOTE the order and direction (eg clockwise) of the parts for polygons determines if the part if a hole or not
    ' it is up to the client to interpret the order and draw accordingly
    Dim geom As List = shp.getShape(0)
    
    Log($"This shape has ${geom.Size} parts"$)
    
    Dim partzero As List = geom.Get(0)
    
    Log($"First part has ${partzero.Size} coordinates"$)
    
    Log("List of coordinates for part")
    For Each xyzm As List In partzero
        Log($" - x: ${xyzm.Get(0)} y: ${xyzm.Get(1)} z: ${xyzm.Get(2)} m: ${xyzm.Get(3)}"$)
    Next