How To Check For A String In The File And Get Start And End Line Numbers

write the logic in the below given Java method.

Public static boolean updateNetMap(String filepath, String nodename){

// check the file pointed by filepath to have entry for nodename.
// if it is there, get the start line no and end line no
// Based on the line nos, need logic to remove the contents from the file.
}

Below is the sample node entry, which we need to identify and delete (here nodename is WAS_CD1):

WAS_CD1:
:conn.retry.stwait=00.00.00:
:conn.retry.stattempts=6:
:conn.retry.ltwait=00.00.00:
:conn.retry.ltattempts=6:
:tcp.max.time.to.wait=0:

[Code]...