*
The moose likes Beginning Java and the fly likes Byte to long Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "Byte to long" Watch "Byte to long" New topic
Author

Byte to long

munna next
Ranch Hand

Joined: Sep 28, 2004
Posts: 46
Can any body pl explain hot to convert byte[] to long value ?
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
All depends on what's in that byte array. And what order it is in.


Ask a Meaningful Question and HowToAskQuestionsOnJavaRanch
Getting someone to think and try something out is much more useful than just telling them the answer.
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
Moving from SCJP to Java In General (Beginner)...
Ryan McGuire
Ranch Hand

Joined: Feb 18, 2005
Posts: 1007
    
    3
If the byte array has the decimal representation of of a number...


If the byte array has been read from some file, you could get clever and use a ByteArrayInputStream to read bytes out of the bye array and wrap that in (decorate it with) a DataInputStream to convert the bytes to a long. Tom make the code as dense as possible, you could do it all one line:



You'll have to try/catch the IOException that the readLong() might throw. What you do in that case is up to you.

Ryan
Joel McNary
Bartender

Joined: Aug 20, 2001
Posts: 1817

If we want to convert a byte[8] to a long, we would do something akin to the following:



(Note that I haven't tested this, and bit-shifting really isn't for beginners anyway.) So, the question is, how do you want a byte array to translate to a long?


Piscis Babelis est parvus, flavus, et hiridicus, et est probabiliter insolitissima raritas in toto mundo.
 
 
subject: Byte to long