How to handle solr delta-import in file based datasource -

i trying implement delta-import in solr indexing working fine,in case when indexing data database.but want implement on filebased datasource.

my data-config.xml file datasource type="com.solr.datasource.datasource" name="suggestionsfile"/>

<document name="suggester">     <entity name="file" datasource="suggestionsfile">         <field column="suggestion" name="suggestion" />    </entity> 

and using dataimporthandler in solrconfig.xml file.i not able post config file,i tried post,but don't know why not showing.

my datasource class read text file , return list of data,that solr index .its working fine in case of full-import not working in case of delta-import.pls suggest else need do.

the filedatasourceentityprocessor supports filtering list based on "newerthan" attribute:

<entity     name="fileimport"     processor="filelistentityprocessor"     newerthan="${dataimporter.last_index_time}"     .. other options .. >     ... </entity> 

there's complete example available online.