Last week, we had the author of TDD for a Shopping Website LiveProject. Friday at 11am Ranch time, Steven Solomon will be hosting a live TDD session just for us. See for the agenda and registration link
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Paul Clapham
  • Ron McLeod
  • Jeanne Boyarsky
  • Tim Cooke
Sheriffs:
  • Liutauras Vilda
  • paul wheaton
  • Henry Wong
Saloon Keepers:
  • Tim Moores
  • Tim Holloway
  • Stephan van Hulst
  • Carey Brown
  • Frits Walraven
Bartenders:
  • Piet Souris
  • Himai Minh

I/O mark supported?

 
Ranch Hand
Posts: 219
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
why does this code says mark not supported?

[ corrected [code] tags ]
[ May 25, 2002: Message edited by: Jessica Sant ]
 
Ranch Hand
Posts: 2120
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
FileReader inherits marksupported() from Reader, and doesn't overrides it. Thus the default implementation which returns false is available to FileReader.
BufferedReader overrides the method to return true, because thanks to its buffer is able to support the mark operation.
 
Thiru Thangavelu
Ranch Hand
Posts: 219
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thanks Jose. But what is the use of of mark? I thought it would skip the characters. But skip() does that. So, where is mark() and reset() are used? An example is really appreciated.
 
Jose Botella
Ranch Hand
Posts: 2120
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I am sorry I have never used such methods.
This is from the API


Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parse, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If this happens within readlimit bytes, it allows the outer code to reset the stream and try another parser.


Thus they seem useful when writing parsers. For the matter I have got by with StringTokenizer and StreamTokenizer classes.
As the API quote says a possible use could be writing two parsers for a text file. The general one could do its work untill it finds a complicated expression that must be given to the specialized parser. The general parser could mark the stream and "toss an exception". The specialized parser could now reset the stream for reading again the expression to blame.
 
I got this tall by not having enough crisco in my diet as a kid. This ad looks like it had plenty of shortening:
free, earth-friendly heat - a kickstarter for putting coin in your pocket while saving the earth
https://coderanch.com/t/751654/free-earth-friendly-heat-kickstarter
reply
    Bookmark Topic Watch Topic
  • New Topic