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

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3answers
2k 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 ...
7
votes
1answer
662 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
4k 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
869 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
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
761 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
2answers
169 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?
5
votes
2answers
750 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?
5
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2answers
4k 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
1answer
9k 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 ...
5
votes
1answer
2k 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" # ...
5
votes
1answer
332 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
1k 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
452 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
5k 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
12k 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?
4
votes
4answers
19k 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 ...
4
votes
2answers
970 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
2k 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
663 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
2answers
941 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
1answer
44 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 ...
4
votes
1answer
2k 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 ...
4
votes
3answers
617 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
718 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
645 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
326 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
2answers
932 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
1answer
894 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 ...
3
votes
2answers
74 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
1answer
361 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
3answers
547 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
3k 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
1answer
35 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
2answers
7k 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
1answer
875 views

Cannot kill a java process

I have a java process that cannot be killed. I have tried every method I know, or that I have found on the internet to no avail. I have tried: killall java kill -9 <pid> kill -11 <pid> ...
3
votes
2answers
5k 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 ...
3
votes
2answers
471 views

Java process, swap (/proc Solaris10) memory highly utilized

How can I analyze high swap memory utilization of Solaris 10 for Java processes?
3
votes
2answers
1k views

How to fix icedteanp plugin error?

I'm using openSUSE 11.3 with "latest updates". I have installed vimprobable and uzbl. Whenever I start one of those two browsers, I get the error message: icedteanp plugin error: Failed to run ...
3
votes
1answer
81 views

How do I change the Java Security level?

We've got an ancient (internal use only) self-signed app that refuses to run now with the changes to the JRE. Working on getting a code signing certificate and rebuilding it, but that's horribly slow ...
3
votes
3answers
1k views

A system-wide way to set or get $JAVA_HOME in Ubuntu?

I wonder whether Ubuntu itself provides a system-wide way to find the current JAVA_HOME or whether there is right place for setting JAVA_HOME. Mac OS X does well in this, for /usr/libexec/java_home ...
3
votes
1answer
298 views

Java on FreeBSD

Is it possible to get the latest Java (Java 7u3 or Java 6u31) on FreeBSD? Everything i found on the internet is outdated. I currently have 6u24 from the packagemanager which works for now but may get ...
3
votes
0answers
16 views

Flipping Control/Command in GNOME breaks Alt key in JVM

I want to switch Control and Command modifier keys in GNOME / Debian Jessie, because I use a Macintosh laptop. I have managed to get these changed via the TweakTool -> Typing panel, like this: Ctrl ...
3
votes
0answers
96 views

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

How to reproduce in Awesome WM v3.5.2: Install OpenJDK or Oracle Java 7. This bug has been observed with both. Start a new Awesome WM session with the default configuration. Start either jEdit or ...
3
votes
0answers
99 views

RES memory more than initial and maximum memory for java

We have a java application running on Centos 6.4 what we notice is that the RES is around 370m which is more then the allocated max that is 256m. Does this signify that we the application is leaking? ...
3
votes
0answers
131 views

Implement Java/JavaFX on ARM

I am working on ARM Linux. I have found this link that says that JavaFX could work on ARM. I am confused about Embedded Java SE and JavaFx ARM. Do I need to setup a JVM for those or not? I have ...
3
votes
2answers
328 views

Running jobs in parallel on Ubuntu - I/O contention differences between Perl and Java

Apologies if this is off topic - it concerns the relative efficiencies of running I/O-heavy Perl/Java scripts in parallel on a Ubuntu system. I have written two simple versions of a file copy script ...
3
votes
0answers
302 views

VMO Changes After Adding New RAM To AIX?

We have a server at a client site running AIX 5.3, which we just up the RAM to 32GB, from initially 16GB (if I'm not mistaken). This server is our Application server running J2EE applications on top ...