6a770cbd_o_Splunk___Splunk_SDK_for_Java__Description
[Parameter] host_regex [Input type] monitor, oneshot [Description] 
A string that specifies a regular expression (regex) to use for extracting a "host" field from the path. If the path matches this regular expression, the captured value is used to populate the "host" field for events from this data input. The regular expression must have one capture group.
How to get data into Splunk | Splunk SDK for Java
Description