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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252
votes
0answers
337k views

How do I install Oracle Java JDK 7? [duplicate]

If I downloaded the latest JDK from Oracle, do I just download the .tar file and extract it to /usr/lib/jvm/?
200
votes
21answers
320k views

How can I install Sun/Oracle's proprietary Java JDK 6/7/8 or JRE?

I want to install Oracle's JRE and to update to the latest version with the Software Updater when they released. Is there a Ubuntu package that is provided by Canonical or Oracle? Before release Java ...
76
votes
11answers
165k views

How do I install Oracle JDK 6? [duplicate]

Most of the software is not thoroughly tested with Java 7 and I would like to install Oracle's JDK 6.0 on Ubuntu 11.10. Could someone please provide me the instructions for the same?
68
votes
9answers
88k views

How do I install Java?

How do I install Java and also the plugin in my browser so websites with Java work?
35
votes
10answers
91k views

How to correctly remove OpenJDK/OpenJRE and set SunJDK/SunJRE as Default

Ubuntu seems to favour OpenJDK/JRE very much over Sun JDK/JRE. Even after I installed Sun JRE, JDK and plugin and spent some time plucking out OpenJDK-related packages, apt-get has installed them back ...
34
votes
1answer
52k views

How do I update Oracle Java 7 (JDK and JRE)

Recently, I've installed JDK 7 from the Oracle site, using these instructions. Now, I'm wondering what is the correct method to update it (or, better, to keep up-to-date automatically)? For instance, ...
33
votes
9answers
97k views

How to completely uninstall Java?

How can I completely remove all traces of Java on my system? I already know how to install it in case I need it again.
28
votes
11answers
87k views

How can I install Minecraft?

I have tried many tutorials but none of them are clear enough. I have also tried installing it using Wine but it won't update and Wine goes gray and stops working. Does anybody know an easy way to ...
28
votes
7answers
80k views

Installing Chrome Java Plugin

I've been trying to install the Java plugin for Chrome for a couple hours now, and I figured it was time to ask people with more experience. I can't seem to get it working. My current Java version is ...
28
votes
2answers
17k views

“sha256sum mismatch jdk-7u3-linux-x64.tar.gz ” error when trying to install Oracle Java

i recently tried installed java 7 on ubuntu 12.04 and i think i screwed something up I followed the instructions given here. First you need to remove openjdk for this run the following command from ...
28
votes
6answers
8k views

How can I remove duplicate icons for “launched” java programs in the launcher?

When launching java programs (like IntelliJ IDEA and Crashplan) in Natty's Unity launcher, duplicate icons are shown (see image). For IntelliJ I created the .desktop file, for Crashplan the .desktop ...
24
votes
2answers
24k views

Is there a way to update all Java related alternatives?

Is there a way to quickly switch over all the Java related alternatives using update-alternatives? For instance, if want to switch Java over to 7, I run sudo update-alternatives --config java and ...
23
votes
4answers
40k views

How to replace OpenJDK 6 with OpenJDK 7?

Surprisingly (as OpenJDK 7 was released to general availability about 4 months ago) Ubuntu 11.10 still uses OpenJDK 6 instead of 7 by default. How do I best fix this? I'd prefer to remove OpenJDK 6 ...
21
votes
0answers
4k views

How can I install the latest version of Sun Java (JRE)? [duplicate]

Possible Duplicate: How can I install Oracle Java JRE 7? Is there a reliable method to install the current version of Sun Java? Update 18 is in the repos, but it looks like Sun is up to ...
20
votes
4answers
71k views

How can I tell what version of Java I have installed?

I want to start toying around with java (eventually getting to the point where I can write basic little programs for android or web), but I've managed to have java messed up on my computer (from past ...
19
votes
3answers
58k views

Installing Java 7 Update 25 on 12.04 LTS?

How can I install Java on Ubuntu 12.04? I have: Java(TM) SE Runtime Environment (build 1.7.0_21-b11) Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)
17
votes
4answers
31k views

How to set JAVA_HOME for OpenJDK?

How can we set JAVA_HOME environment variable for OpenJDK?
17
votes
6answers
20k views

Unsatisfied Link Error and missing .so files when starting Eclipse

I upgraded to the 12.04 beta yesterday. Now, when I try to start Eclipse, I get the splash screen and then this error message: An error has occurred. See the log file ...
16
votes
4answers
4k views

Installing Java Automatically (With Silent Option)

I'm trying to install Java through apt-get. I found this PPA of Java Installers, however, when I add the repository, update and then issue the apt-get install -y command, the installer for java ...
16
votes
5answers
4k views

Java application launcher not staying in Unity launcher

I'm using IntelliJ IDEA, which is a Java application. When it runs (invoked through Dash) it shows a launcher icon with no name. I've tried several times to right-click and select "keep in ...
14
votes
3answers
12k views

Open-source, free Java Decompiler

Is there any open source Java Decompilers for Ubuntu, preferably in the repositories and/or GPL'ed? Both JAD and JD, the most popular decompilers I've found after a bit of googling, seems to be ...
13
votes
4answers
52k views

How can I execute a .jar file from the terminal

I know that to execute a file, I use the . command, then the file name with a space between them. But I'm trying to execute a .jar file using the . and it does not work. I went into the properties and ...
13
votes
2answers
14k views

Setting JDK 7 as default

four@twenty:~$ file /etc/alternatives/java /etc/alternatives/javac /etc/alternatives/java:symbolic link to `/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java' /etc/alternatives/javac:symbolic link to ...
13
votes
9answers
26k views

Minecraft in jdk 1.7.0_u2 x64

I have Ubuntu 11.10 64-bit and I installed JDK 1.7.0 update 2 x64 via webupd8 page. But currently I have problem with minecraft game. After downloading launcher from Minecraft.net and lauch the game ...
13
votes
5answers
10k views

Will Sun's Java be available from Canonical's partner repository?

I just discovered that Oracle's (Sun's) Java6 has vanished from the Canonical's partner repo. Before java was taken from all repositories I had purchased Minecraft for play in Ubuntu. After recent ...
13
votes
3answers
955 views

oracle-java8-installer results in “apt” removal? [closed]

I have been been running trusty since the first alpha release, pulling daily updates. I also installed the oracle-java7-installer from the WebUpd8 PPA. Today I noticed during a dist-upgrade that ...
12
votes
2answers
8k views

How can I get a java apps to use the GTK+ theme?

Is there a way to get java apps to use my gtk theme?
12
votes
2answers
812 views

Horizontal scrolling treated as right click in Java applications

I've enabled horizontal scrolling for my touchpad in Ubuntu 11.04, but when using it in Java applications (NetBeans in my case) it is instead as a right click. Horizontal scrolling works perfectly in ...
11
votes
2answers
29k views

Installing Eclipse Kepler and Java JDK

I need some help to set up the Eclipse Kepler 4.3 and Java JDK last version on Xubuntu, I whould like to do it by the command terminal. Which are the right commands?
11
votes
2answers
72k views

How to set default Java version?

I have followed all the instructions stated at this question, but am encountering some problems with the last part of it. I actually have version 6.22 of java and would like to update to version ...
11
votes
4answers
1k views

Why do most GNOME developers prefer Python over Java for GTK+ programming?

I only know C and Java. And I really don't want to learn another language when I can work with what I already know. I haven't ever written a GTK+ application, but I am planning to start with an ...
11
votes
2answers
11k views

Changing JVM in Java

I only recently discovered the different JVM's on the wiki page and thought I'd start tinkering. Its been difficult to find documentation on how to configure Java on Ubuntu though. Lets say I wanted ...
10
votes
2answers
16k views

Minecraft jar not marked as executable

I looked up several tutorials on how to install and they dont work. I do everything correctly but then i get this: The file '/home/mike/Downloads/minecraft.jar' is not marked as executable. ...
10
votes
3answers
30k views

How can I enable java in Chromium?

I've got java working on firefox in Ubuntu 11.04, but using the same page on chromium tells me java cannot be found. How can I enable java on chromium in my Ubuntu 11.04?
10
votes
3answers
16k views

How to make a jar file run on startup & and when you log out?

I have no idea where to start looking. I've been reading about daemons and didn't understand the concept. More details : I've been writing a crawler which never stops and crawlers over RSS in the ...
10
votes
5answers
19k views

How do I make java default to a manually installed JRE/JDK?

I have Ubuntu 12.04 amd64 installed on my machine, on the previous versions of Ubuntu it was deadly easy, now there is this command update-java-alternatives with a really bad man page. I just have my ...
10
votes
5answers
9k views

How to uninstall OpenJDK?

I don't want OpenJDK installed on my Ubuntu 13.04 system, but trying to uninstall the openjdk-7-jre yields the following message: $ sudo apt-get purge openjdk-7-jre Reading package lists... Done ...
9
votes
8answers
26k views

Java JRE will not install due to “tar: Error is not recoverable” error

I have been trying to get Java for the past day now. I followed several tutorials but I keep getting the same error. After I put in tar -xvf jre-7u4-linux-i586.tar.gz it says Cannot open: No such file ...
9
votes
5answers
34k views

How to compile a .java file

How can I compile a .java file. What programs will I need and if I need java jdk I need help installing that. I'm very new to ubuntu so any program I need to install I will need a tutorial on how to ...
9
votes
2answers
26k views

Java on Ubuntu server 12.04? [duplicate]

I'm a little confused at the moment. My back story in short, is that I'm trying to set up a Minecraft server on an Ubuntu server I've recently set up, obviously to do this I needed Java, but after ...
9
votes
4answers
18k views

'tools.jar' is not in IDEA classpath

I am a new user of Linux, it has been recommended to me by my friend. He told me to install software called IntelliJ Idea IDE. Well I have been following the tutorial. But now when I try to open ...
9
votes
3answers
3k views

Does java security flaw affects ubuntu also?

There are rumors about an actual java security problem. The BSI advises people to deactivate java plugins version 7 and prior in all kind of OS, even in linux. Does this mean, I should deactivate ...
9
votes
3answers
13k views

How can I view or start Java Web Start Applications?

Where can I find a menu or launchers for Javaws apps that I have installed? I am using OpenJDK x86.
9
votes
5answers
2k views

How do I make my java app compatible with the unity global menu?

I like to develop in Java but also want compatibility with the global menu? Is there a way? Please help.
9
votes
2answers
7k views

ca-certificates-java fails when trying to install openjdk-6-jre

I use a VPS with Ubuntu Server 10.10 x64. I want to use Java and run the command sudo apt-get install openjdk-6-jre but it fails because the installation encounted errors while processing ...
9
votes
2answers
1k views

Why does the “monospace” font look great in Terminal and gedit, and terrible in IntelliJ IDEA?

Why does the "monospace" font look great in Terminal and gedit, and terrible in IntelliJ IDEA? IDEA uses Java's Swing library, and I understand it might be an issue with this. Is there a known fix?
9
votes
4answers
22k views

How to install openjdk-7-jdk on Ubuntu 12.04 without dragging in unrelated GUI and sound packages?

Ubuntu 12.04.2 LTS What's going on here? # apt-get install openjdk-7-jdk Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be ...
9
votes
1answer
118 views

prevent java applications from creating tray icon

With Ubuntu 13.04 the possibility to whitelist (and consequentely blacklist) certain applications from creating a tray icon is gone. Since then the tray icons of Java applications and Wine icons are ...
8
votes
3answers
26k views

Install 32bit Java (OpenJDK) on 64bit Ubuntu 12.04 [duplicate]

I have to run Juniper VPN on the 64bit Ubuntu 12.04. I have installed openjdk-7-jre, openjdk-7-jdk and icedtea-7-plugin. After the browser prompts to install the Juniper VPN, I check it has been ...
8
votes
2answers
9k views

“No such file or directory” when invoking java

I'm trying to re-install Oracle JDK 7 32 bit to 64 bit Ubuntu (previously 64 bit JDK was installed). JDK is currently present at /usr/lib/jvm/jdk1.7.0. I invoke sudo update-alternatives --remove ...