Java is a general-purpose programming language and a computing platform called the Java Virtual Machine (JVM).

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3answers
5k views

How to trace a java-program?

As a sysadmin I sometimes face situations, where a program behaves abnormally, while not creating errors at all or creating nonsense error-messages. In the past - before java came in - there were two ...
9
votes
1answer
436 views

How to fix Java applications mouse pointer offset in Awesome WM?

How to reproduce in Awesome WM v3.5.2 through 3.5.5 (so far): Install OpenJDK or Oracle Java 7. This bug has been observed with both. Start a new Awesome WM session with the default configuration. ...
8
votes
2answers
941 views

Java location from /usr/bin/java

I'm trying to find my java location within my Linux system and got this [980@b449 ~]$ which java /usr/bin/java [980@b449 ~]$ readlink -f $(which java) ...
7
votes
5answers
26k views

Problem to launch java at Debian: “error while loading shared libraries: libjli.so”

I'm trying to launch java: $ java -version java: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directory $ ldd ...
7
votes
1answer
2k views

What is the safe way to allow Java 7 to run on SELinux

Short version: What is the most secure way to allow Java 7 to run on (with?) SELinux? Long version: Sorry in advance if I use incorrect terminology. I'm really just a Java developer with a meager ...
7
votes
3answers
7k views

Command Line Tool for monitoring Java Heap

Is there any command line tool for monitoring the heap size usage of Java in CentOS?
6
votes
2answers
1k views

What is Debian's stance regarding GCJ and OpenJDK?

Both OpenJDK and GCJ are available for install on Debian, and now I wonder what's happening. Don't these provide same functionality?
6
votes
2answers
961 views

Java problem - nearly looks like a virus?

I have a weird problem since about a week. When I wake up my computer from suspend, a java process starts and consumes about 170 % CPU capacity. I analyzed the java process a bit: it connects to ...
6
votes
2answers
1k views

Invoke Syscalls from Java

Is there a way to invoke syscalls directly from Java, or is it necessary to first call a native method?
6
votes
2answers
636 views

How can I install Sun JDK on a Debian based system?

I can't find any .deb packages for Sun's Java Development Kit. How can I install it on my Debian machine without causing conflicts with the already installed openjdk packages?
6
votes
1answer
15k views

Installing openjdk-7-jdk does not update java (which is still version 1.6)

I am having issues updating Java. I am running Ubuntu 11.10. I can execute sudo apt-get install openjdk-7-jdk and it completes successfully. javac -version is 1.7, however java -version is 1.6. This ...
6
votes
1answer
3k views

How can i know which unistd.h file is loaded?

I have several unistd.h files in my Ubuntu Linux. I've one on: /usr/include/asm/unistd.h This file has this directives: # ifdef __i386__ # include "unistd_32.h" # else # include "unistd_64.h" # ...
6
votes
2answers
2k views

How do I change file associations from the command line?

The system in question is Solaris, using the Gnome type interface (Java Desktop Environment). We have occasional issues with users managing to mess up their file assocations (most notably .tif). ...
5
votes
4answers
988 views

Is there a JVM daemon?

I'm curious, is there a JVM which runs as an OS daemon, and forks when a new process should be started in it ( i.e. like init, or zygote process on Android )? If no, why not? I am not talking about a ...
5
votes
1answer
20k views

How to completely remove Java 6 and install Java/JDK 7 on Linux Mint 13

How can I completely remove Java 6 and install Java/JDK 7 on Linux Mint 13?
5
votes
2answers
5k views

Looking for a Java class in a set of JARs with find, unzip, grep

I was trying to find the JAR containing a Java Class. JARs are in zip format. My first attempt was: $ find -name "*3.0.6.RELEASE.jar" | xargs -l1 unzip -l \ | grep stereotype.Controller ...
5
votes
4answers
16k views

java plugin does not work in chromium-browser (all possible attempts exhausted)

I was using google chrome browser on Ubuntu 12.04 machine, recently I needed to switch to chromium-browser. I am using the version that is available on the Ubuntu software centre. The problem is that ...
5
votes
1answer
2k views

What is the difference between JAVA_HOME and update-alternatives?

I have been trying to figure out the best way to run OpenJDK Java Runtime as default Java for my Fedora box and use Oracle JDK 6 for Android development namely for running Android SDK Manager, Android ...
5
votes
2answers
1k views

How can I expose JAVA_HOME to applications running under X and/or Gnome?

I'm trying to run IntelliJ from Gnome3's Applications menu, but it complains the JAVA_HOME variable is not set. I have the Java installation under my home folder. I managed to export the variable in ...
5
votes
1answer
3k views

Use certain version of JRE / JDK for certain programs

I use ArchLinux, and an IDE called PyCharm. On its download page, it recommends using Java 6 instead of OpenJDK. ArchLinux has an OpenJDK package (jdk7-openjdk) that I have installed, installed, and ...
5
votes
1answer
356 views

Installing OpenJDK on a Netbsd Sparc64 Server

I am currently working on a project that involves running the lift framework on a sun sparc64 architecture. Due to limited support from more popular unix distros, I am running NetBSD 64-bit on the ...
5
votes
1answer
2k views

How do I update IcedTea?

I've only been using Linux for about a month. I'm running Mint 13. I'm trying to use www.goproblems.com but it tells me that my IcedTea is out of date. I hoped there was a package but I can't find ...
5
votes
1answer
586 views

Dead keys not working in Java Swing applications

I'm currently using Ubuntu 10.10 and Netbeans 7.0 and I can't type accented letters with dead keys any more. It's not a version specific problem seems it's related with Swing since I've got the same ...
4
votes
3answers
9k views

Kill only one Java process

I usually run few Java applications, one for server running locally and other for some IDE like NetBeans. And from time to time, after lots of redeployments, my server get stuck on ...
4
votes
3answers
6k views

What to do to run GUI Java app in chrooted environment?

In my case Java app is JDownloader. I prepared chroot environment as explained here: http://www.0x61.com/forum/post5240333.html#p5240333 and here: http://interreality.org/~reed/java-chroot.html ...
4
votes
1answer
216 views

Poorly performing java application vs poorly performing server

This is a very generic question, but it has been coming up more and more often for me. I would like to try and determine an appropriate course of action for this generic case, as I think it could ...
4
votes
1answer
2k views

How to get Oracle java 7 to work with setcap cap_net_bind_service+ep

I am trying to grant the java executable the right to open ports below 1024 on Linux. Here is the setup /home/test/java contains the Oracle Server JRE 7.0.25 CentOS 6.4 Here is what getcap ...
4
votes
2answers
2k views

Linux running slow with 0 swap left

Our Linux server is responding very slowly. top doesn't show any excessive CPU usage. I noticed that even though there's about 5GB of free memory, the system is using all of swap with no free swap ...
4
votes
2answers
5k views

Adding a folder of jar files to my path

Unix newbie here. I have java tools that I need to use. The tools are in a folder full of jar files. I wanted to add this folder to my path, for the obvious reasons, but after I edit my .bash_profile ...
4
votes
1answer
841 views

How do get unix sort to sort in same order as Java (by unicode value)

I shell out sorting to the unix sort command in a Java program I've written. However I am having problems arising from Java's string comparison behaving differently than the comparisons done by sort. ...
4
votes
3answers
1k views

Mathematica makes no sound under Ubuntu 11.04

After waiting for days for my license I now got the opportunity to install Wolfram Mathematica 8 at home. However, neither the Play nor the Speak functions are doing anything as it seems that ...
4
votes
2answers
7k views

How to install JRE on firefox with fedora (64bits)

What do I need to run Java web applications on firefox with my 64bits fedora 17? I can't pass this test but I have installed the x64 rpm from there. What is missing? Additional note: I tried to ...
4
votes
2answers
178 views

Lots of processes killed by SIGTRAP

Since yesterday, my Linux (Fedora 20) randomly kills processes for no reason at all (at least from my point of view), and the bugs reports say that all these processes are "killed by SIGTRAP". It ...
4
votes
0answers
114 views

How do I execute in background / return early?

For reference, I'm using phpseclib to control a remote SSH server using the 'root' account. I have to start/stop a java process which is ran in the background. Stopping works fine with killall java ...
4
votes
3answers
1k views

Uniquely identifying java processes with same name

I have two java processes which run using the same file name, MyApp.jar (for example). /usr/java/latest/bin/java -jar MyApp.jar These jars exist in different places and use different ...
3
votes
4answers
13k views

Java “Could not reserve enough space for object heap” even though there is enough RAM

I am currently having some issues running Java. It won't start because of heap issues. But I have more than 9 GB Ram free (or even 16 GB if you assumed the cache would be empty). This is the error I ...
3
votes
4answers
1k views

How to run java process to be seen not as 'java…' in processes list?

Is it possible to run a Java process in Linux in a way that it could be seen in ps as some sort of alias? It would be easier to restart it when it is down.
3
votes
2answers
832 views

What is meant by stack in connection to a process?

From the book Advanced programming in the Unix environment I read the following line regarding threads in Unix like systems All the threads within a process share the same address space, file ...
3
votes
2answers
424 views

Capturing new output after deleting the output file

I'm runnig a java server on Debian with this command: java -jar myapp.jar [args] >> log.txt Once I gzipped the log file to send it and then I realized the original file was gone, leaving me ...
3
votes
1answer
865 views

update-alternatives just for one user

I'm using a shared server. On that server different versions of Java are installed: Selection Path Priority Status ...
3
votes
2answers
1k views

How to to remove libgcj from Debian?

I am doing Java programming on Debian. By default Debian 6.x ships with libgcj JVM. On starting eclipse it shows a warning that this JVM is deprecated and may cause problems. For this reason I ...
3
votes
2answers
130 views

How to make apt recognize an installed tar package?

I've installed Oracle Java. I want to be able to remove OpenJDK, but when trying to do so apt wants to install another version of Java. How can I configure apt so that it knows I already have a ...
3
votes
4answers
11k views

Installing JDK 7 on debian

So I just rented a dedicated server running Debian, and I know nothing about Linux. Anyway, I want to install the JDK 7, first I connected through SSH and granted myself administrator rights by ...
3
votes
3answers
784 views

Monitoring progress/liveness of background jobs

I have started a background job. Is there a way to know how it is progressing, and whether it has stopped? My command line is like: java weka.classifiers.trees.J48 -t data.arff J48-data.model ...
3
votes
2answers
2k views

Why isn't my environment variable visible from the command line?

I'm trying to run the James SMTP server on Lion (Mac OS X 10.7.2). When I do this: sudo JAVA_HOME=/Library/Java/Home ./james-2.3.2/bin/run.sh it works fine. However, I'd like to make JAVA_HOME an ...
3
votes
1answer
6k views

Run java classfile from terminal

I have a compiled java file somefile.class, and when i cd into the right folder and do: java somefile it works but when i call it from another folder: java folder/somefile it doesn't work, it gives me ...
3
votes
2answers
596 views

Java doesn't show menu text

I startet netbeans/intelliJ/squirrelSQL after I didn't use it for a few days/weeks and now the menu doesn't show text. There are just the underlineds. My system: ArchLinux (everything up to date, ...
3
votes
1answer
41 views

program executing for 2 days

I have a java program which implements the Hungarian algorithm. I made changes to the existing code in such a way that the input is read from file. I have a pretty huge input around 32,000 rows for ...
3
votes
1answer
71 views

locate java source code in jdk7

I have installed Jdk7 in Ubuntu 14.04 and it is successfully configured and I can use java libraries in code. The problem is that I am trying to locate java source code, but not able to find the jar ...
3
votes
3answers
1k views

Messed up bash.bashrc file, commands not working anymore

Trying installing Java, I tried to add it to the executable path with the line: export PATH=/usr/lib/jvm/jdk1.7.0_60/bin:$PATH in the system-wide /etc/bash.bashrc file. For some reason this ...