I have put together a small sample of how to get property values from a Windows Powershell command into Thingworx through an agent using the Java SDK.
In order to use this you need to import entities from ExampleExport.xml and then run SteamSensorClient.java passing in the parameters shown in run-configuration.txt (URL, port and AppKey must be adapted for your system). ExampleExport.xml is a sample file distributed with the Java SDK which I’ve also included in the zipfile attached to this post. You need to go in Thingworx Composer to Import/Export … Import from File … Entities … Single File … Choose File … Import.
Further instructions / details are given in this short video: