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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289
votes
23answers
455k 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 ...
90
votes
11answers
127k views

How do I install Java?

How do I install Java and also in my browser so websites with Java work?
252
votes
0answers
338k 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/?
83
votes
11answers
191k 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?
29
votes
12answers
94k 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 ...
38
votes
1answer
49k views

How do I get Java plugin working on Google Chrome?

Google has updated its Chrome browser to version 35. This new version uses Aura in place of GTK2 and no longer supports NPAPI plugins like Java (both OpenJDK and Oracle). PPAPI plugins like ...
46
votes
9answers
138k 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.
18
votes
6answers
23k 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 ...
39
votes
6answers
141k 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 ...
33
votes
6answers
10k 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 ...
31
votes
2answers
20k 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 ...
40
votes
1answer
77k 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, ...
13
votes
5answers
11k 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 ...
18
votes
1answer
22k views

java plugin in Chromium

Icedtea-7-plugin installed but it does not appears in the list in about:plugins in Chromium. Not able to execute java applets. Tried installing Icedtea-7-plugin but in vain. Using openjdk7 in 14.04
8
votes
3answers
37k views

How run a .jar file with a double-click?

I have a problem running .jar files by double-clicking them. When I go to the Properties dialogue I can't find Java--only Archive Manager in the list of programs. But java -jar somefile.jar opens the ...
7
votes
1answer
7k views

How do I reenable opening jar files by double clicking on them?

How can I make "double click to run" the default behaviour of a jar-file on Nautilus? There is no "Open with OpenJDK Java 7 Runtime" on the "Open with" tab under Properties.
6
votes
2answers
2k views

is OpenJDK Vulnerable to 0-Day Exploit?

I was curious to know if OpenJDK is also vulnerable to the Zero-Day Exploit that is currently afflicting Java 7 because of which experts are telling people to disable Java until a solution is found on ...
13
votes
9answers
28k 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 ...
10
votes
2answers
15k 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 ...
12
votes
6answers
29k 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 ...
16
votes
2answers
10k 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?
22
votes
3answers
35k views

How to install OpenJDK 8 on 14.04?

IMPORTANT: If you need this in 14.04, vote for this bug: https://bugs.launchpad.net/ubuntu/+source/openjdk-8/+bug/1341628 Java 8 is now available according to ...
6
votes
0answers
10k views

How to install Oracle Java web plugin on Chrome in 12.04? [duplicate]

Possible Duplicate: How can I install Sun/Oracle’s proprietary Java 6/7 JRE or JDK? I've tried a whole lot of guides, but at best I ended up with neither Google Chrome not Firefox ...
3
votes
1answer
382 views

Eclipse not using PATH

I am facing an issue of Eclipse not picking up the VM from the PATH environment variable. I follow the below steps to reproduce the error : Downloaded the appropriate version of Oracle's JDK from ...
2
votes
1answer
861 views

Oracle java7 config

I've installed Oracle Java 7 according to this guide. When I run sudo update-java-alternatives -s java-7-oracle, it gives me : update-alternatives: error: no alternatives for ...
0
votes
2answers
752 views

Best Practice for Installing Java on Ubuntu / is it secure?

Much has been said about the security risks associated with Java. However the burp suite (pen test) depends on Java. Is it secure to install Java? if so, how to properly do it? My Ubuntu is a web ...
6
votes
3answers
986 views

How to revert back to OpenJDK?

I had installed sun-java, but I want to revert back to OpenJDK 7. I was trying to re-install from the terminal using the command sudo apt-get install openjdk-7-jre, same from Synaptic and Software ...
1
vote
1answer
2k views

JDK x64 fails to unpack in Ubuntu 13.04

New to ubuntu, I have just installed the OS in my VMPlayer. I am trying to install Oracle (Sun) Java 6 onto my Ubuntu 13. As per the instruction given here I download jdk-6u45-linux-x64.bin from the ...
1
vote
1answer
1k views

IcedTea plugin not working in Midori web browser

I have Lubuntu 13.04, and I use the Midori WebBrowser. I initially had a problem with the plugins, but later on, I could activate Flash and Java. I use the IcedTea browser plugin to view Java content. ...
14
votes
3answers
26k 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 ...
30
votes
4answers
52k 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 ...
13
votes
2answers
13k 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 ...
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 ...
5
votes
1answer
2k views

How to prevent openjdk-6-jre-headless from clobbering Oracle JDK installation?

My automated build server runs a job that depends on Apache Ant. The script invokes apt-get install ant. Ant depends on openjdk-6-jre-headless which runs update-alternatives making itself the default ...
12
votes
4answers
45k 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?
3
votes
4answers
10k views

Running 32-bit Firefox with sun-jre in 64-bit Ubuntu [duplicate]

I am trying to run juniper networks connect program to vpn into work and it only works on 32bit sun jre. All the things I have found with google failed so far. I can't use any scripts, like ...
4
votes
2answers
10k views

Replacing the OpenJDK with the Oracle JDK

I've had the archive file for Oracle's JDK for some time and have been running java applications through ~/Downloads/jdk1.7.0/bin/java -jar <jarfile> for some time, but I'm wondering if there's ...
3
votes
1answer
8k views

how to run java program in ubuntu in following situtations

sachin@sachin-Lenovo-G550:~$ java -version java version “1.7.0_21″ OpenJDK Runtime Environment (IcedTea 2.3.9) (7u21-2.3.9-1ubuntu1) OpenJDK Server VM (build 23.7-b01, mixed mode) When I ran the ...
3
votes
1answer
13k views

Cannot Update Java plugin for Google Chrome

I keep getting the "Java plugin out of date" box whenever I open a page with embedded Java. I use the link provided, which has no auto-install. I've unzipped the tarball into /usr/lib/jvm/. I've used ...
3
votes
6answers
13k views

Cannot execute Java program: UnsupportedClassVersionError

I have installed JDK 6, but I can't execute a Java program. For example, I have made test.java. I compile it with javac tes.java and there's no error when I compile it, but when I want to execute ...
1
vote
2answers
6k views

Installing Matlab 2012a (32-bit) in Ubuntu 12.04 LTS java problem

This is my first posting here, so please be gentle. I am having a problem installing Matlab 2012a (32-bit) in Ubuntu 12.04 LTS. I have trawled around the web and have seen similar problems reported, ...
0
votes
0answers
45 views

how to fix a port number statically for client request on client side?

I am on a Assignment to implement unicast multicast broadcast in java socket programming. While implementing multicast part I decided to do it on my own system itself, so for the purpose of ...
0
votes
1answer
686 views

How can I scale Java-based applications up for a high DPI screen?

There are some applications (mainly java based) that don't follow the global 2x scale I set in the screen-settings. So these apps are really tiny on my high DPI screen with 3200x1800px. How can I get ...
40
votes
10answers
114k 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 ...
26
votes
2answers
30k 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 ...
20
votes
2answers
115k 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 ...
28
votes
4answers
104k 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 ...
25
votes
3answers
57k views

How to set JAVA_HOME for OpenJDK?

How can we set JAVA_HOME environment variable for OpenJDK?
18
votes
4answers
33k 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 ...
16
votes
2answers
14k views

Eclipse (ADT) crash Failed to write core dump. Core dumps have been disabled

i found my problem here: how to fix “Failed to write core dump. Core dumps have been disabled” error while running java and here: Eclipse crashing on startup and here: Eclipse continue crash Nothing ...