[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

appending data in a file

Posted on 2003-11-13
8
Medium Priority
?
594 Views
Last Modified: 2010-03-31
Hello people
Well i want to periodically write to a file basically its a log file that is constantly updated from time to time but i dont want the file to be overwritten rather i want to update the file like each time the file is opened for the WRITE operation i should start from the end of FILE and then write the DATA in other words i want to APPEND data to this file is there any way i can do that in JAVA please help me out

Thanks in advance
Asif Iqbal
0
Comment
Question by:asifiqbal2k
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
  • 2
  • +1
8 Comments
 
LVL 7

Expert Comment

by:grim_toaster
ID: 9745824
I would suggest looking into the API documents as the first port of call, in particular the java.io package.

The class FileWriter is probably the one you're after, but look into the API's for full details, as learning how to read the API's is one of the most important things you can do!  And you should have a general knowledge of certain areas, i.e. java.util, java.lang and java.io, I'm sure there are other important areas also, but these are a good starting point.
0
 
LVL 2

Expert Comment

by:Tols
ID: 9745828
Appending to a file can be done this way (I use this in my own logging library):

BufferedWriter logWriter = new BufferedWriter(file, true);
logWriter.write(buf);
logWriter.close();
0
 
LVL 2

Accepted Solution

by:
Tols earned 60 total points
ID: 9745829
A little correction:
BufferedWriter logWriter = new BufferedWriter(new FileWriter(file, true));
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 

Author Comment

by:asifiqbal2k
ID: 9745856
Hello people
Well i want to periodically write to a file basically its a log file that is constantly updated from time to time but i dont want the file to be overwritten rather i want to update the file like each time the file is opened for the WRITE operation i should start from the end of FILE and then write the DATA in other words i want to APPEND data to this file is there any way i can do that in JAVA please help me out

Thanks in advance
Asif Iqbal
0
 
LVL 5

Expert Comment

by:lwinkenb
ID: 9745909
Tols comment correctly answers your question.
BufferedWriter logWriter = new BufferedWriter(new FileWriter(file, true));
0
 
LVL 5

Expert Comment

by:lwinkenb
ID: 9745910
The true parameter pasted to the FileWriter means you are opening the file to append.
0
 

Author Comment

by:asifiqbal2k
ID: 9754272
well ok now one more problem now what i want to do is write data to file by specifying a position like i want to write DATA to a particular location in the FILE is there any way to that.
0
 
LVL 5

Expert Comment

by:lwinkenb
ID: 9754987
Only if you want to overwrite the data that's already there.  There is no way to insert data at a particular point without overwriting data though.  What you need to do is read the entire file contents into memory (into a String or a StringBuffer), then insert the text you want into the string or string buffer.  Then write that back onto the file.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

An old method to applying the Singleton pattern in your Java code is to check if a static instance, defined in the same class that needs to be instantiated once and only once, is null and then create a new instance; otherwise, the pre-existing insta…
Java had always been an easily readable and understandable language.  Some relatively recent changes in the language seem to be changing this pretty fast, and anyone that had not seen any Java code for the last 5 years will possibly have issues unde…
Viewers learn about the “for” loop and how it works in Java. By comparing it to the while loop learned before, viewers can make the transition easily. You will learn about the formatting of the for loop as we write a program that prints even numbers…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
Suggested Courses

656 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question