who is familiar with SAP Java Base IDoc Class Library?

The JCoIDocSample3.java provided by SAP demonstrated the jco listener server to read idocs from SAP by tRFC port,but now my SAP creates idocs into a server directory by "File" port, so I want to implement java program read idocs existed in the directory, how java program can get the idocs object or idocs list?

who can give me some example codes?

Appreciate for your help.

Leslie.