Java how to copy part of a file

Posted by user3479074 on Stack Overflow See other posts from Stack Overflow or by user3479074
Published on 2014-08-06T19:47:58Z Indexed on 2014/08/23 22:21 UTC
Read the original article Hit count: 327

Filed under:

java

|

file-io

I have to read a file and depending of the content of the last lines, I have to copy most of its content into a new file. Unfortunately I didn't found a way to copy first n lines or chars of a file in java.
The only way I found, is copying the file using nio FileChannels where I can specifiy the length in bytes. However, therefore I would need to know how many bytes the stuff I read needed in the source-file.

Does anyone know a solution for one of these problems?

© Stack Overflow or respective owner

Related posts about java

Tomcat 6: Access Control Exception?

as seen on Server Fault - Search for 'Server Fault'
I'm trying to setup a tomcat6 server, and I'm trying to match another setup someone else established. However, my deployment (default Ubuntu install) uses a policy.d/ directory structure, and the established server just uses a catalina.policy file. I've tried setting every entry in policy.d to match… >>> More
Problem in creation MDB Queue connection at Jboss StartUp

as seen on Stack Overflow - Search for 'Stack Overflow'
I am not able to create a Queue connection in JBOSS4.2.3GA Version & Java1.5, as I am using MDB as per the below details. I am putting this MDB in a jar file(named utsJar.jar) and copied it in deploy folder of JBOSS, In the test env. this MDB works well but in another env. [ env settings and… >>> More
failing to establish connection between Postgres db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using Postgres and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When I try to connect it gives "ClassNotFoundException". Here is what I get when I try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
failing to establish connection between postgre db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, For i am using postgre and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When i try to connect it gives "ClassNotFoundException". Here is what i get when i try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
Migration and deployement problems JBoss 4.2.2.GA to JBoss 6.0.0.M2

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I'm trying to migrate an application running on JBoss 4.2.2.GA to JBoss 6.0.0.M2 I give you some log to explain my problem : boot.log : 2010-03-16 09:59:29,406 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] (Thread-2) Failed to load profile: Summary of incomplete deployments… >>> More

Related posts about file-io

File io error Python

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a program that monitors a folder with word documents for any modifications made on the files. The error -Windows Error[2] The system cannot find the file specified- comes when I run the program, open a .doc within the folder make some changes and save it. Any suggestions on how to fix this… >>> More
Problem with File IO and splitting strings with Environment.NewLine in VB.Net

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I was experimenting with basic VB.Net file read/write and encountered this problem. I don't know whether it has something to do with the File IO or the String splitting. I am writing text to a file like so Dim sWriter As New StreamWriter("Data.txt") sWriter.WriteLine("FirstItem") sWriter.WriteLine("SecondItem") sWriter… >>> More
C# Multithreading File IO (Reading)

as seen on Stack Overflow - Search for 'Stack Overflow'
We have a situation where our application needs to process a series of files and rather than perform this function synchronously, we would like to employ multi-threading to have the workload split amongst different threads. Each item of work is: 1. Open a file for read only 2. Process the data in… >>> More
On MacOSX, in a C++ program, what guarantees can I have on file IO

as seen on Stack Overflow - Search for 'Stack Overflow'
I am on MacOSX. I am writing a multi threaded program. One thread does logging. The non-logging threads may crash at any time. What conventions should I adopt in the logger / what guarantees can I have? I would prefer a solution where even if I crash during part of a write, previous writes still… >>> More
ASP.Net Application Trust Medium File IO Outside Virtual Directory

as seen on Stack Overflow - Search for 'Stack Overflow'
I am trying to determine how suicidal this is... I have a hosting environment where a custom ASP.Net CMS application needs to access the files in the root folder of a website even though it is in a virtual folder so it can be shared accross many sites. I can modify the Medium trust on the server… >>> More