Loading properties from file via Groovy

You can have do it with setup script for the test case.

1. Define a test case level property say PROPERTY_FILE_NAME and have absolute path of property file.
2. For the test case, do a double click, you can see Setup Script. Have below script.

def props = new Properties()
new File(context.expand('{#TestCase#PROPERTY_FILE_NAME}')).withInputStream { 
  stream -> props.load(stream) 
}
props.each {
  testCase.setPropertyValue(it.key,it.value)
}

This script will run each time when test case is invoked.

Looks you are a soapui pro user, try posting quries in pro boards for faster response.