Alternatives to GeometryService for projection

[jackcrawford]

I'm new to ArcGIS. is there an code-only alternative to using the REST Geometry service to perform operations on geometry, e.g. projection, determine an envelope or must I use the geometry service. This is not a mapping app but will run on a Java servlet engine. Need to project multipolygons and polygons (in ESRI JSON format) from SR NAD83 4269 to WGS84 3857 and determine envelope for same.

Thanks for the help.

[nita14]

Dear Jack,

Yes, there are some options:

1) Use ProjectEngine in ArcGIS Runtime for Java. However, Runtime was not designed to work with servlet engine.

GeometryEngine| arcgis-java 

2) Use open - source libraries to perform geometry operations like GitHub - locationtech/jts: The JTS Topology Suite is a Java library for creating and manipulating ve...  and integrate it with your application

3) Use Esri JS Geometry Engine and call Javascript from your application geometryEngine | API Reference | ArcGIS API for JavaScript 4.8 

Hope it helps,

Adam