Search for a pattern in a file and print it in jruby

Question

I have a file with n number of lines. I need to search for a field(SessionId and its value) in it and print its corresponding value.

I have coded to access the file and print it line by line. Need help in getting a field and printing its value.

Sample lines of file:

LastSessionTeardown.cc|598|Resolving:=N2BBSessionGateway.Factory
2013-12-23 06:03:22.488046 UTC VZ_QIP_S3_208 LastSessionTeardown.cc|636 <ERROR>:Failed     to resolve SessionGateway:N2BBSessionGateway.Factory
Cause : user exception, ID 'IDL:omg.org/CosNaming/NamingContext/NotFound:1.0'
2013-12-23 06:03:22.488078 UTC VZ_QIP_S3_208 LastSessionTeardown.cc|640|Total resolved     SessionGateways list(size):=0
2013-12-23 06:03:22.488098 UTC VZ_QIP_S3_208 LastSessionTeardown.cc|642|Out     resolveSGWs::
2013-12-23 06:07:17.485959 UTC VZ_QIP_S3_208 StreamServiceMasterImpl.cc|989|In     createStream::=77D23ECC4649571A367E9C314C4AA7AA
2013-12-23 06:07:17.487706 UTC VZ_QIP_S3_208 StreamServiceMasterImpl.cc|1036|StreamId:     77D23ECC4649571A367E9C314C4AA7AA  **SessionId: C0A800F0DB2A::1387778933::1501** ContentId: vault22_12.mpg 1xGoid: 
2013-12-23 06:07:17.505233 UTC VZ_QIP_S3_208 StreamServiceMasterImpl.cc|989|In     createStream::=E30CC868325B51D288A8E2D95322B840

Note : the file has lots of lines above and below the field specified

Code:

require "java"

include_class "java.io.BufferedReader"
include_class "java.io.FileReader"
include_class "java.lang.String"

fileReader = FileReader.new "protocoltiming.log.txt"

bufferReader = BufferedReader.new fileReader
str = bufferReader.readLine

while str
puts str.to_s
str = bufferReader.readLine
 end

Kindly help me on what to be added to this code?

Answer 1

while str
  str = bufferReader.readLine
  session_id = str.strip.scan(/SessionId: (.+)\s/)[0][0] if str.include?("SessionId: ")
  if session_id
    # session_id found
  else
    # session_id not found
  end
end

There is actually no need to loop through the lines. You can just read the file and use regular-expression to find required text. But whatever suits your cat. Sometimes reading whole file could be really problematic if it is too big.

HTH

Answer 2

done. this works!

require "java"

include_class "java.io.BufferedReader"
include_class "java.io.FileReader"
include_class "java.lang.String"

fileReader = FileReader.new "StreamService.log"

bufferReader = BufferedReader.new fileReader

#puts str
str = bufferReader.readLine

while str = bufferReader.readLine
#puts str.to_s

sessionid = ""

  sessionid = str.match(/SessionId:(.*)ContentId/)

  if sessionid.to_s != ''
    puts "Session ID = #{sessionid[1]}"
  end

end