Java is a programming language originally developed by Sun Microsystems. Questions here should be about the installation, configuration and troubleshooting a JVM (Java Virtual Machine) or a JRE (Java Runtime Environment). Programming questions (unless directly related to Ubuntu) should be asked ...

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How do I upgrade to the latest Java 7 while not losing my existing Java dependencies and add-ons?

$ uname -a Linux X51 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux $ java -version java version "1.6.0_23" OpenJDK Runtime Environment (IcedTea6 1.11pre) ...
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1answer
12k views

How to downgrade Oracle Java 7 to Java 6?

I recently changed my Wubi install into a full install, which runs a lot smoother than Wubi. I had to re-install all my stuff, because I did it the lazy-man's way, and after reinstalling Java, I ...
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1answer
942 views

Is it necessary to have openjdk 6 installed in Ubuntu 12.04?

Is it necessary to have openjdk 6 installed in Ubuntu 12.04 or will openjdk 7 provide all the support I will need for Java functionality (generally speaking)?
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3answers
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How to run .jar files with Sun Java 6?

I cannot seem to open Minecraft.jar from the file browser. Everytime I try, I select open with, then Sun Java and nothing happens. I've tried the terminal too, but that fails and just reports a load ...
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votes
1answer
4k views

Installing tomcat from repo with Java from Oracle

Since Java 6 from Oracle is not supported with Ubuntu repositories anymore, I installed it by downloading the package from java.oracle.com, unpacking it in /opt and adding symlinks in /usr/bin. Now I ...
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2answers
14k views

update-alternatives: error: no alternatives for

I tried to follow the excellent answer to the question How to correctly remove OpenJDK and JRE and set the system use only and only Sun JDK and JRE?, but there seem to be some side effects: ...
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votes
1answer
261 views

How to confirm sun java 6's license agreement automatically?

When I install this: sudo apt-get install -y sun-java6-bin sun-java6-jdk sun-java6-jre sun-java6-plugin I am still forced to select OK and YES during the install. The -y switch doesn't work for ...
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2answers
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Davmail Java terminates with SIGSEGV after 11.10 Upgrade

One of my favorite programs, davmail, crashes now after upgrading to 11.10. Just checking if there is a quick fix before I submit a bug report. Thanks. $ davmail # # A fatal error has been detected ...
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1answer
10k views

How To Install JAVA EE in Ubuntu 11.04 properly?

I am totally new to Ubuntu and just installed it for the first time. I am trying to install JAVA EE in my ubuntu. I downloaded it from oracle website and its an .sh file. I followed instructions from ...
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votes
1answer
923 views

How do I uninstall all instances of Java and blacklist it from being installed again?

For security reasons I want to remove/uninstall all instances of Java from my computer and prevent it from being installed again. On Windows computers I would simply just not install the software ...
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1answer
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Java bin file won't install manually [closed]

I downloaded a java bin file manually from here. Then I tried to install it using the following commands. But I am not able to install it. Can anybody help me to install manually? ...
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1answer
3k views

How to set up Java-based services for startup?

What's the best way to set up a Java-based program to run an service and start on boot? upstart (pre-start script and post-stop script ?) plain old SysV init? (start-stop-daemon ?) In my case I am ...
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2answers
1k views

Running J2ME (Java Micro Edition) Applications

What's the easiest way to run J2ME (Java phone apps) on Ubuntu?
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1answer
1k views

Error running Java web application with OpenJDK Java7 runtime in Ubuntu 14.04

I have fresh Ubuntu 14.04 install on my HP Pavilion g6 laptop. I have installed OpenJDK and IcedTea plugin in order to run Java applications as explained here. But when I am going to chess.com ...
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1answer
1k views

Multiple JDK is not working properly in Ubuntu 14.04

JDK versions (jdk1.7.0_21 and jdk1.7.0_55) Installed and Configured like below. jdk1.7.0_21 update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0_21/bin/java" 1 ...
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3answers
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Problem to set JAVA_HOME

In ~/.bash_profile I set the following: export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-i386/bin/java export PATH=$PATH:/usr/lib/jvm/java-7-openjdk-i386/bin After saving and close I ran: sudo su ...
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votes
1answer
2k views

Tomcat and Eclipse Integration Error : “Unknown version of Tomcat was specified.”

I am using Ubuntu 13.10 and gnome 3.10. I have followed this tutorial Set up Eclipse and Tomcat 7 on Ubuntu 12.10 to create Java RESTful Web Services with Jersey to setup tomcat and eclipse. but ...
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1answer
287 views

Pogo.com games won't work, says outdated java

I am trying to get my Ubuntu 12.04 laptop to be able to run games on pogo.com First none of the games on pogo would work because of outdated flash. Then I learned of google chrome with pep flash and ...
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1answer
5k views

Java memory usage ballooning to all RAM when running Minecraft Server

When I run Minecraft server, over time (a few hours to a few days) the memory usage by Java balloons to take up all available computer memory and the server performance then degrades: lags, players ...
3
votes
2answers
178 views

Ubuntu with Java Error

I have Oracle Java installed on my computer. Latest version 1.7 and path variables set properly. But most applications in Ubuntu from Software Center that require Java needs Open JDK Iced Tea etc. I ...
3
votes
1answer
758 views

Install JUnit with Oracle Java 7 already instaled

I am running Ubuntu 12.10 with Oracle Java 7 installed (as described here). I want to install JUnit 4 but if I do a simple sudo apt-get install junit, it starts to download openjdk and the like (which ...
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votes
3answers
9k views

install red5 server on an ubuntu12.04 server

I've been struggling with this during 2 weeks without get it done. I'm building a website where the users will have to record a video and post it as there cv and for this I need a RTMP server. I ...
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votes
4answers
2k views

Netbeans shows only blank window

I am not able to launch Netbeans. When I launch it for the first time I normally get the netbeans splash screen, but after that nothing happens. When I try to launch it again, a small blank window ...
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1answer
521 views

Poor Audio in Blackboard Collaborate (Elluminate Live) on Ubuntu 11.10

I already have Sun Java (not OpenJDK) installed, but I'm still having audio issues. OpenJDK didn't display the slides, which was fixed by Sun Java, but the audio was bad in both of them. Is there any ...
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1answer
11k views

First time using Java Web Start in Ubuntu - Fatal Launch Exception

I've been using Ubuntu for a while and Java Web Start applications have never "just worked" in the current or any prior version, so I ignored them until now. However, now I have a need to get them ...
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4answers
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How do I remove OpenJDK?

I had removed OpenJDK installed by default from Ubuntu Software Center. Eclipse had been showing that Installed JRE is OpenJDK. I wanted eclipse should be configured to jdk I already installed and ...
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votes
2answers
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How to install Eclipse J2EE IDE from a tarball?

I have downloaded Eclipse 3.6.1 as a tar.gz file from eclipse site. Then I extract using cmd: tar -zxvf eclipse-jee-helios-SR1-linux-gtk.tar.gz after execute this cmd I got eclipse folder in this ...
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2answers
535 views

Packaging a Java web application: Reuse tomcat6 or separate process?

I would like to package my java web application http://kunagi.org/ for Ubuntu (and Debian). Should the package create a user kunagi, provide an init script and configuration files for the existing ...
3
votes
1answer
2k views

Eclipse Kepler crashes without any log entry [duplicate]

I'm using Ubuntu 13.10 Saucy Salamander 64bit and Eclipse Kepler 64bit terminates after some random time without response. The windows simply disappears. There's also no entry about the crash in ...
3
votes
1answer
936 views

Why can't I play mp3 files in java

I am making a study guide in java to help me learn Japanese, but I have been having a hard time getting it to speak Japanese to me. Espeak did not work, so I used this code to get a .mp3 file and ...
3
votes
1answer
2k views

Run different java based on command line parameter

I have multiple java installations on my machine and need to use different versions all the time. I have found that the currently used JVM can be changed by the commands update-alternatives and ...
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votes
2answers
3k views

Oracle Java 7 on Linux PowerPC

I give up trying to figure this one out on my own. The information on this website: http://www.yellowdog-board.com/viewtopic.php?t=2935 and on this one: ...
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votes
2answers
6k views

Unable to understand what jdk location is

I have java installed correctly for sure. aaa@ubuntu:~$ whereis java java: /usr/bin/java /usr/bin/X11/java /usr/local/java /usr/share/java aaa@ubuntu:~$ whereis javac javac: /usr/bin/javac ...
3
votes
1answer
139 views

Java installation failed

I am using Ubuntu 11.10 on flash memory due to corrupted hard drive that could hardly keep OS. Usually when computer get down because of empty battery or other reason it is reinstalled, the Ubuntu on ...
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1answer
1k views

Trouble installing Matlab due to java.lang.NoClassDefFoundError

So whenever I try to install Matlab, the first image appears, but then goes away and that's the end of it. Here's what I'm doing- user@host$> cd ~/mathworks_downloads user@host$> unzip ...
3
votes
1answer
1k views

Cannot install JDK 7

i have already extracted the files in the tar.gz files i also tried the sudo update-alternatives but it only says it doest have too since i already have one jdk and then when i try java -version it ...
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votes
2answers
319 views

I can't find or run downloaded Geogebra

I can't find it. I can't run it. I have no idea what to do now that it's on my computer. I'm new at this stuff.
3
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1answer
556 views

Ubuntu 12.04 version of Netbeans doesn't have the JavaFX plugin

I just want to know why does Netbeans 7.0.1 from the official Ubuntu 12.04 doesn't have all the plugins (in especial the JavaFX plugin) on it while the official Netbeans from the website (even the ...
3
votes
1answer
753 views

How can I remove an unfinished java installation installed via terminal?

Well, since I was so stupid to install the java via terminal with official package, it stuck on the licence agreement screen, because I had to accept it, but no key from my keyboard worked to accept. ...
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votes
2answers
506 views

Installing mods on Minecraft 1.0 does not work for Mo' Creatures

In attempting to get the Mo' Creatures mod working on Kubuntu 11.10 with OpenJRE-6 I get the following error: # # A fatal error has been detected by the Java Runtime Environment: # # SIGSEGV (0xb) ...
3
votes
1answer
155 views

CUPS Print Delays [closed]

I am a developer of an open source Java printing plugin for the web browser and we have a client that reports 250ms delay in printing on Ubuntu, but no other OS. He has tested printing on Windows and ...
3
votes
2answers
276 views

Battery Indicator Missing, Cannot Install Because No JDK 7

I'm really new to the whole linux deal, but I'm on a laptop and a battery gauge would be extremely helpful. Whenever I try sudo apt-get install indicator-power it gives me: `Reading package ...
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votes
0answers
172 views

How do I control the vmem when forking, as I'm getting different results on 10.04 lts and 12.04 lts? [closed]

Expected behavior (Ubuntu 10.04 LTS): mike@boontoo10:~$ java -version java version "1.6.0_45" Java(TM) SE Runtime Environment (build 1.6.0_45-b06) Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, ...
3
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1answer
77 views

How can I find out how often a program has started in Ubuntu?

How can I find how often a program (like firefox, teeworlds, thunderbird, etc.) has launched? I'm a Java programmer, so solutions that must be implemented programmatically are acceptable, and ...
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4answers
9k views

How to set the default Java version

I have been using Java 6 on Ubuntu 11.10, but now I want to update to version 7. I've installed version 7 via PPA as described here. If I run sudo update-alternatives --config java I get the ...
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0answers
592 views

Webex crashing/lockup Firefox / Chromium Browsers - Ubuntu 12.10 [closed]

When launching webex from firefox or chromium browser. Browser freezes and stops responding. Browser process must be killed to exit. Please help me troubleshoot this. Here are my setup details and ...
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votes
2answers
600 views

how to enable in chrome icedtea7 java plugin instead of icedtea6?

My chrome browser in ubuntu 12.04 uses iced6 plugin. Test http://java.com/en/download/testjava.jsp shows java6, but via update-alternatives I switched java/javac to using openjdk-java7
3
votes
1answer
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Java 1.7 update 07 and Google Chrome

I've just updated Java from 1.6 to 1.7 via the Software Centre - removing the old Java 1.6 and selecting the new Java 1.7. Firefox works fine. But when I use Google Chrome to access a Java test ...
3
votes
0answers
126 views

How to do a ppa for a java ant project?

I was doing a launchpad ppa for my ant project using jdeb. when I had the unpleasant surprise in the last step that ubuntu ppa actually builds the package from the repository, not just accepts signed ...
3
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0answers
74 views

Unity sometimes can't seem to re-show a java GUI app (jpasswords) [closed]

I use a password manager called jpasswords because I can run it on most platforms and it can be self contained on a usb drive. Under Unity in Ubuntu 12.04, using openjdk, it runs fine, but if it get's ...