Q:

Reading custom property in a processor

I am trying to create a custom processor (with Java) in Apache Nifi to read the user's custom property.  Is it possible to create a processor to extract the user key value pair?  If so, how should I go about extracting them?  
Are the user custom properties stored within a dictionary in a library of some nifi.processor.*? 
Please refer to the image below:

Ideally, I want to extract the dynamic values of Property and Value for all inputs above.  ie. {" Custom Property 1": "Some value", "Custom Property 2": "Another Value", "Custom Property 3":"Third Value"}

A:

The user-defined properties are available in your ProcessContext like all properties are, but they have a flag for being dynamic.  Here's a snippet for iterating over the user-defined properties:
context.getProperties().keySet().stream().filter(PropertyDescriptor::isDynamic).forEach()

Fill in the lambda in the forEach() with your logic for handling the properties.