I installed JDK using apt-get install but I don't know where my jdk folder is. I need to set the path for that. Does any one have a clue on the location?
This depends a bit from your package system ... if the java command works, you can type readlink -f $(which java) to find the location of the java command. On the OpenSUSE system I'm on now it returns /usr/lib64/jvm/java-1.6.0-openjdk-1.6.0/jre/bin/java (but this is not a system which uses apt-get).
On Ubuntu, it looks like it is in /usr/lib/jvm/java-6-openjdk/ for OpenJDK, and in some other subdirectory of /usr/lib/jvm/ for Suns JDK (and other implementations as well, I think).
Debian is the same.
For any given package you can determine what files it installs and where it installs them by querying dpkg. For example for the package 'openjdk-6-jdk': dpkg -L openjdk-6-jdk
update-java-alternatives -l
will tell you which java implementation is the default for your system and where in the filesystem it is installed. Check the manual for more options.
$ which java
should give you something like
/usr/bin/java
This question will get moved but you can do the following
which javac
or
cd /
find . -name 'javac'
Use find to located it. It should be under /usr somewhere:
find /usr -name java
When running the command, if there are too many "Permission denied" message obfuscating the actual found results then, simply redirect stderr to /dev/null
find /usr -name java 2> /dev/null
Another best way to find Java folder path is to use alternatives command in Fedora Linux (I know its for Ubuntu but I hit this post from google just by its headline). Just want to share incase people like me looking for answers for fedora flavour.
To display all information regarding java
alternatives --display java
Three Step Process:
First:
open Terminal->$ whereis java
it would give output like this:
java: /usr/bin/java /usr/share/java /usr/share/man/man1/java.1.gz
Second:
ls -l /usr/bin/java
It would give output like this:
lrwxrwxrwx 1 root root 22 Feb 9 10:59 /usr/bin/java -> /etc/alternatives/java
Third:
ls -l /etc/alternatives/java
output is the JDK path:
lrwxrwxrwx 1 root root 46 Feb 9 10:59 /etc/alternatives/java -> /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
Simple, try it:
It's /usr/local/java/jdk[version]
This question still seems relevant, and the answer seems to be a moving target.
On my debian system (buster):
> update-java-alternatives -l
java-1.11.0-openjdk-amd64 1111 /usr/lib/jvm/java-1.11.0-openjdk-amd64
However, if you actually go look there, you'll see there are multiple directories and symbolic links placed there by the package system to simplify future maintenance.
The actual directory is java-11-openjdk-amd64, with another symlink of default-java. There is also an openjdk-11 directory, but it appears to only contain a source.zip file.
Given this, for Debian ONLY, I would guess the best value to use is /usr/lib/jvm/default-java, as this should always be valid, even if you decide to install a totally different version of java, or even switch vendors.
The normal reason to want to know the path is because some application wants it, and you probably don't want that app to break because you did an upgrade that changed version numbers.
the command: sudo update-alternatives --config java will find the complete path of all installed Java versions
On Linux Fedora30 several versions of the full java JDK are available, specifically package names:
java-1.8.0-openjdk-devel.x86_64
java-11-openjdk-devel.x86_64
Once installed, they are found in: /usr/lib/jvm
To select the location/directory of a full development JDK (which is different from the simpler runtime only JRE) look for entries:
ls -ld java*openjdk*
Here are two good choices, which are links to specific versions, where you will have to select the version:
/usr/lib/jvm/java-1.8.0-openjdk
/usr/lib/jvm/java-11-openjdk
on OpenSUSE 13.1/13.2 its: /usr/lib64/jvm/java-1.6.0-openjdk-(version-number)
version-number can be 1.7.x 1.8.x etc. check software manager witch version you have installed...
André
This is the best way which worked for me
Execute this Command:-
$(dirname $(readlink $(which javac)))/java_home
below command worked in my debain 10 box!
root#debian:/home/arun# readlink -f $(which java)
/usr/lib/jvm/java-11-openjdk-amd64/bin/java
Related
I have started learning groovy and I just came across the SDKMAN utility.
To give it a try I folllowed the installation guidelines at the official site of sdkman and tried to run the below command to install sdkman on Windows 10 :
set SDKMAN_DIR="E:/sdkman" && curl -s "https://get.sdkman.io" | bash
But I donot see any sdkman folder present in my E drive.
When I try to re-run the command it says :
Looking for a previous installation of SDKMAN...
SDKMAN found.
======================================================================================================
You already have SDKMAN installed.
SDKMAN was found at:
"E:/sdkman"
I am just confused as to why am I not able to see it with my eyes. I have even tried enabling view hidden items.
Tried to execute which sdk. but it clearly says which: no sdk in (..
...
has anyone else experienced similar issue. Any help is highly appreciated.
which bash implementation are you using under windows? cygwin? gitbash?
I believe at least in gitbash that the path syntax is /e/sdkman/, i.e. you would do:
export SDKMAN_DIR="/e/sdkman" && curl -s "https://get.sdkman.io" | bash
but it's been a long time since I was on windows and I suspect this is bash-implementation specific (i.e. it might differ between cygwin and gitbash for example).
If this assumption is correct, the syntax you were using might have created a directory called E:/sdkman under your user's home directory or whatever directory you happened to be in when you ran this. Just guessing here, but worth a look.
I installed Scala on Ubuntu using the following
sudo apt-get install scala
~$ which scala
/usr/bin/scala
~$ whereis scala
scala: /usr/bin/scala /usr/bin/X11/scala /usr/share/man/man1/scala.1.gz
~$ scala -version
Scala code runner version 2.9.1 -- Copyright 2002-2011, LAMP/EPFL
My question is what should I put in the variable SCALA_HOME? /usr/bin ?
Today I installed scala using "apt-get install scala" and confirmed the scala jar files are located in /usr/share/java
You should be able to set your SCALA_HOME to /usr/share/java and have it all work. I assume you want to use NetBeans so you will need to set SCALA_HOME in your .profile (or .bash_profile) rather than in your .bashrc because NetBeans won't see any variables set in your .bashrc unless you start it from the command line
$ find / -maxdepth 6 -iname \*scala\*jar 2> /dev/null
/usr/share/java/scala-dbc.jar
/usr/share/java/scala-partest.jar
/usr/share/java/scala-partest-2.9.1.jar
/usr/share/java/scala-dbc-2.9.1.jar
/usr/share/java/scalacheck.jar
/usr/share/java/scalap.jar
/usr/share/java/scala-library-2.9.1.jar
/usr/share/java/scala-compiler-2.9.1.jar
/usr/share/java/scala-library.jar
/usr/share/java/scalacheck-2.9.1.jar
/usr/share/java/scala-compiler.jar
/usr/share/java/scala-swing-2.9.1.jar
/usr/share/java/scalap-2.9.1.jar
/usr/share/java/scala-swing.jar
For me its: /usr/share/java/scala
I determined this by doing
dpkg -L scala
This assumes you install scala using APT.
As of today I couldn't find an easy (and reliable) way of setting this.
As per Alex (in the comment above) installing from tarball (downloaded from scala-lang.org) into /location/of/scala/untar
Then I set export SCALA_HOME=/location/of/scala/untar in my .bashrc
Everything works for now!
I had the same issue and I did some digging
This takes into account that you are using sudo dpkg -i scala-2.11.4.deb; where the debian package has been downloaded
The SCALA_HOME should be /usr/share/scala; This is based on the following
/usr/bin/scala is a symbolic link to /usr/share/scala/bin/scala
/usr/bin/X11/scala is also a symbolic link to
/usr/share/scala/bin/scala
The way I see the scala package is installed in /usr/share/scala which should be your SCALA_HOME
I installed the untarred scala into /usr/local/share as it is on the scala download site.
In my .bashrc, I placed the following line:
export PATH="/usr/local/share/scala-2.11.8/bin:$PATH"
works great from terminal regardless of what directory I'm in.
If you have installed Scala using
$apt-get install scala
then, after a successful install to see where it installed, run
which scala
If this command shows you the path to scala binaries.
Now run
pwd
Now export SCALA_HOME path into either of these environment files
~/.bashrc
or
/etc/profile
export SCALA_HOME=<output of pwd>
The SCALA_HOME should be the directory where you install scala from.
For example, the name of this directory may be scala-2.9.2.
I am trying to install OpenCL(AMD) on linux, but I am stuck on the last step(install ICD)
It seems like ICD HAS to be installed at /etc/OpenCL/vendor, but I don’t have root access to the computer.
Is there any way to make OpenCL work without installing ICD? (or maybe through an environment variable to add search path for ICD files?)
It just seems really inconvenient for people like us when ICD file path is hardcoded.
Put the ICD-files in /some/path/icd and then export the path like so:
export OPENCL_VENDOR_PATH=/some/path/icd
It used to work in previous versions at least. I would be surprised if they changed it.
Here is a sketch of how to do a "user" or "local" install of the AMD OpenCL SDK without administrator privileges. Step 9 also provides a method to use the AMD OpenCL platform along with selected platforms installed system-wide.
The installation directory /local/install/path and current SDK version just need to be modified to suit.
Download the AMD OpenCL SDK 64 bit.
$ tar -xvzf AMD-APP-SDK-v2.8-RC-lnx64.tgz
$ tar -xvzf icd-registration.tgz
$ cd AMD-APP-SDK-v2.8-RC-lnx64
$ mkdir /local/install/path
$ cp -r lib /local/install/path
$ cp -r include /local/install/path
$ cp -r ../etc /local/install/path
Optional: make symbolic links for desired system installed platforms:
$ ln -s /etc/OpenCL/vendors/nvidia.icd /local/install/path/etc/vendors/nvidia.icd
$ export OPENCL_VENDOR_PATH=/local/install/path/etc/vendors
$ export LD_LIBRARY_PATH=/local/install/path/lib/x86_64:$LD_LIBRARY_PATH
$ cc -I/local/install/path/include -L/local/install/path/lib/x86_64 -lOpenCL demo.c
$ ./a.out
Just an update on this as I suddenly found myself having the same issue (again). I had to disable the buggy Mesa icd which apparently is crashing under non-root runs. Frustrating as it's more a problem with the API handling errors while listing each platform more than an error with permissions or clinfo. Make sure to disable each platform icd to isolate which one is having issues. Hope this helps someone later.
I'm running IntelliJ Idea under linux. I have created a project and a module inside it, and in that module I have a class (MyClass.class) and when I'm trying to run it from IDE, I get
ERROR: MyClass.class (No Such file or directory)
Can somebody explain me why IntelliJ Idea doesn't recognize the classes inside my module? I know it should be a problem regarding module settings but I can't figure it out. I'm using Ubuntu 11.10
OK I place here the paths and everything for all to see :)
type : echo $PATH
Result:
/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/lib/jvm/java-7-openjdk-i386/bin:/usr/lib/jvm/java-7-openjdk-i386/bin:/usr/lib/jvm/java-7-openjdk-i386/bin
type: echo $JAVA_HOME
Result:
/usr/lib/jvm/java-7-openjdk-i386
type: ./idea.sh
Result:
NOTE: If you have both Sun JDK and OpenJDK installed
please validate either IDEA_JDK or JDK_HOME environment variable points to valid Sun JDK installation
Arkde, I have a possible explanation why Jaroslav's solution with JDK7 didn't work for you.
Maybe you had mixed Java versions in various alternatives items, possibly conflicting with the version that environment variables like JAVA_HOME and JDK_HOME point to?
Maybe something points to the /usr/lib/jvm/default-java symlink as the JDK home, and that symlink points to a different version of JDK than intended?
Did you try resetting alternatives for all Java tools to version 7? Like this:
update-java-alternatives --list
# ...see what JDK's are available, choose the one that corresponds to Java 7
# and set it to be the default in alternatives:
sudo update-java-alternatives --set java-1.7.0-openjdk-amd64
# or interactively:
sudo update-alternatives --config java
What do the following commands output on your system?
echo $JAVA_HOME
echo $JDK_HOME
ls -l /usr/lib/jvm/default-java
update-java-alternatives --list
update-alternatives --list java
I had exactly the same problem.
I've performed strace on the Idea process and in the log I saw it trying to open several .class files without the path to them specified - like open("SomeClass.class", O_RDONLY) = -1 ENOENT (No such file or directory) - no path to the project output directory and to appropriate package.
So I've apt-get installed JDK 7 along JDK 6:
apt-get install openjdk-7-doc openjdk-7-jdk openjdk-7-jre openjdk-7-jre-headless openjdk-7-jre-lib openjdk-7-source
In Ubuntu 11.10 Oneiric, OpenJDK 6 isn't removable if you want OpenJDK 7. JDK 7 is dependent on JDK 6...
So I've:
updated alternatives configuration as specified above,
changed the /usr/lib/jvm/default-java symlink to point to java-7-openjdk-amd64 ,
double checked all the environment variables (my JAVA_HOME and JDK_HOME both point to /usr/lib/jvm/default-java),
reconfigured my project's SDK appropriately (and for all the modules in the project),
and voila - problem solved!
Solved it. Remove all jdk/jre you have, install openjdk7.
Add this line to .bashrc
export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-i386/
export PATH=$PATH:$JAVA_HOME/bin
Run Idea. Profit. :)
I experienced the same problem. What I found is that the underlying system-wide Java version doesn't matter, so there is no need to set JAVA_HOME or update_alternatives. All I had to do was change some settings in IDEA:
Add a Java SDK, either OpenJDK 7, or Oracle JDK 6 or 7 (File -> Project structure -> SDKs)
Select it as Project SDK (File -> Project structure -> Project)
Check that Make checkbox is enabled, otherwise IDEA will not compile your project, also verify that class file is available in the output directory and you are running with the classpath of the correct module.
If the problem remains, send a sample project to support.
I've run into the same problem - I moved my projects (and Idea settings) from a laptop with Ubuntu 10.04 and sun-jdk-6 to a PC with Ubunty 11.10 and openjdk-6. Upon project rebuild I got MyClass.class (No Such file or directory) errors for ALL classes.
Thanks to Jaroslav, his (almost) solution did helped - I can't explain why, perhaps it would work with sun-jdk-6 too... So, I installed openjdk-7, without removing openjdk-6, and set 7th as a project's JDK in Idea. (I did not change anything in environment variables.) With jdk7 it compiled.
PS I should've written it as a comment to Jaroslav's post, not a separate answer, but I don't yet have enough reputation to do this...
Try to run IDEA using
sh -c "export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-i386 && ./idea.sh"
When it starts press Ctrl+Alt+Shift+S to open Project Settings dialog. In the left panel choose Project and verify that Project SDK is configured correctly (at least it is not red).
I am having trouble getting Openfire to work. I done the following:
[root#jiaoyou logs]# which java
/usr/bin/java
and I've run this command:
ln -s /usr/bin/java /opt/openfire/jre/bin/java
but when starting Openfire, it still says:
cannot run command `/opt/openfire/jre/bin/java': No such file or directory
It seems like a permission issue, but I don't know how to fix that.
This was solved for me, in CentOS6 64bit, using the following commands:
cd /opt/openfire/jre/bin
cp java java.bak
rm java
ln -s /usr/bin/java java
service openfire start
If you're on a 64-bit machine, you should install zlib package for 32-bit architectures.
For Redhat/Centos, use:
yum install -y zlib.i686
/usr/bin/java is just a shell script that runs the actual binary. If you don't have the JAVA_HOME environment variable set correctly, it might not be able to locate the binary if invoked through a symlink like that.
Another thing to keep in mind is that some distros of Linux put /usr/bin/java in place even though you haven't installed the Sun JRE. Don't bother trying to use the GNU version of Java, it's rubbish. Do you know if the Sun JRE is installed or not? What does "java -version" tell you?
I think the correct answer is using the right command to start openfire. I have found that "service openfire start" actually doesn't work.
I attempted the above mentioned method of removing the java executable from opt/openfire/jre/bin and all that did was force me into reconfiguring all of my current openfire settings. Thank god I made that java.bak file.
I believe the proper method to stop|start|restart is from /opt/openfire/bin and run ./openfire start or from anywhere "/opt/openfire/bin/openfire start"
At least that's what worked for me.