Java -install vs PATH - java

I am new to Ubuntu and trying to install a particular version of java.
I downloaded the jdk1.7.0_51 binaries in my Ubuntu machine and exported the variable JAVA_HOME='home/programs/jdk1.7.0_51 and the PATH=$PATH:$JAVA_HOME/bin. However when I type java -version in the command line I get:
java version "1.6.0_27"
OpenJDK Runtime Environment (IcedTea6 1.12.6) (6b27-1.12.6-1ubuntu0.12.04.4)
OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode)
The displayed java version (1.6.0_27) is different than the version declared in the PATH. There was an older version which I removed through the software center but the issue remains. Any help would be greatly appreciated.

That's because you already have openjdk installed (by default probably) on your system and the binaries provided by openjdk are already registered in $PATH. And that's where your problem is. Downloading the oracle jdk binaries and installing them in a custom location and exporting that location in JAVA_HOME, is not enough. You also need to add the path to the jdk binaries (javac, java, jar, etc) to the PATH environment variable.
A better way to do this is to install the oracle jdk via pre-packaged versions provided by ubuntu community: link. This would configure the path for you and set the necessary environment variables. And use alternatives to configure which would be the default jdk to use:
update-alternatives --config java
Or simply remove openjdk if you don't need it.

Related

Uiautomatorviewer not finding JAVA_HOME

When I try to start uiautomatorviewer.bat i get this error:
ERROR: No suitable Java found. In order to properly use the Android Developer
Tools, you need a suitable version of Java JDK installed on your system.
We recommend that you install the JDK version of JavaSE, available here:
http://www.oracle.com/technetwork/java/javase/downloads
If you already have Java installed, you can define the JAVA_HOME environment
variable in Control Panel / System / Avanced System Settings to point to the
JDK folder.
You can find the complete Android SDK requirements here:
http://developer.android.com/sdk/requirements.html
I have a working JDK at C:\Program Files\Java\jdk-9
My system variables are:
JAVA_HOME C:\Program Files\Java\jdk-9
PATH C:\Program Files\Java\jdk-9\bin;D:\Prac\AndroidSDK\platform-tools\bin;D:\Prac\AndroidSDK\tools\bin;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;%ANDROID_HOME%;%ANDROID_HOME%\build-tools\25.0.3;D:\Prac\nodejs\;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;
( ANDROID_HOME D:\Prac\AndroidSDK )
My java version:
java version "9"
Java(TM) SE Runtime Environment (build 9+181)
Java HotSpot(TM) 64-Bit Server VM (build 9+181, mixed mode)
echo %JAVA_HOME% is working OK (printing correct path).
I tried setting JAVA_HOME variable in the .bat script. That didn't work. (But that might be because I'm not sure where exactly in the script should I include it...)
Do you have any idea how to solve this?
Eureka! The problem was that I was using 64bit JDK.
After installation of 32bit version all I needed to do was to set ANDROID_SWT system variable and it is working now.

Can't find Java JDK in IntelliJ, running Fedora 24

I can't find the directory in which to set up Java as my project JDK in IntelliJ. I tried pointing it to /usr/java/java[version-number] but IntelliJ said that it was an invalid directory. (I don't remember exactly what the folder was called, I just remember it was Java 8.)
I did some googling and found out that it may be because it was corrupted, and they recommended wiping it and doing a reinstall... so I deleted the java[version-number] folder in /usr/java and attempted to do a reinstall by downloading the jdk rpm file from Oracle's website, but apparently I still have the 1.8.0 JDK installed?
When I type in java -version into terminal, I get the following:
openjdk version "1.8.0_102"
OpenJDK Runtime Environment (build 1.8.0_102-b14)
OpenJDK 64-Bit Server VM (build 25.102-b14, mixed mode)
I'm not sure where to go from here.
For me the problem was different. I installed IntelliJ's flatpack version of the IDE.
flatpack has restrictions to use the file system.
These directories are blacklisted:
/lib, /lib32, /lib64, /bin, /sbin, /usr, /boot, /root, /tmp, /etc, /app, /run, /proc, /sys, /dev, /var
Exceptions from the blacklist: /run/media
These directories are mounted under /var/run/host: /etc, /usr
So you have to use path something like /var/run/host/usr/lib/jvm/java-1.8.0-openjdk-amd64.
I actually downloaded the IntelliJ Toolbox and installed it from there.
try whereis java maybe it'll show up in your terminal

JDK not found on Debian 8.5

I want to make a python-android-app using this software. I have installed java JDK, when i run java -version i get:
java version "1.8.0_91"
Java(TM) SE Runtime Environment (build 1.8.0_91-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)
However running the line python android.py installsdk from witin rapt directory (as described in the tutorial) tells me that i have no JDK:
I'm compiling a short test program, to see if you have a working JDK
on your system.
I was unable to use javac to compile a test file. If you haven't
installed the Java Development Kit yet, please download it from:
http://www.oracle.com/technetwork/java/javase/downloads/index.html
The JDK is different from the JRE, so it's possible you have Java
without having the JDK. Without a working JDK, I can't continue.
You need to set your jdk to be accesible, and within path / java home :)
Here help from google:
To set JAVA_HOME environment variable, do the following: Launch
Terminal by pressing Ctrl + Alt + T on your keyboard. Depending on
where you installed your Java, you will need to provide the full path.
For this example, I installed Oracle JDK 7 in the
/usr/lib/jvm/java-7-oracle directory.Aug 13, 2012

How to install alt JDK on Mac without overriding current one

Mac here (Yosemite 10.10.5). I am using JDK 8 for all my projects, and recently just inherited an “older” Java 7-based project. I would simply like to download a Java 7 JDK from Oracle's archived JDKs, however it only seems to be available as a DMG (auto-installer).
I’m afraid that if I download this DMG it will auto-install it and make Java 7 my default installation. Whereas, I only want the unzipped JDK on my local file system, so that I can run my Java 7 app off of it (by specifying the full path to the JDK when I run the app locally).
Any ideas as to what my options are?
Most of the information about this can be found in Oracles notes on installation
I believe what you are looking for specifically is under
Determining the Default Version of the JDK:
There can be multiple JDKs installed on a system, as many as you wish.
When launching a Java application through the command line, the system uses the default JDK. It is possible for the version of the JRE to be different than the version of the JDK.
You can determine which version of the JDK is the default by typing java -version in a Terminal window. If the installed version is 8u6, you will see a string that includes the text 1.8.0_06. For example:
% java -version
java version "1.8.0_06-ea"
Java(TM) SE Runtime Environment (build 1.8.0_06-ea-b13)
Java HotSpot(TM) 64-Bit Server VM (build 23.2-b04, mixed mode)
To run a different version of Java, either specify the full path, or use the java_home tool:
% /usr/libexec/java_home -v 1.8.0_06 --exec javac -version

How do I set the default Java installation/runtime (Windows)?

I'm in the situation where I've installed the JDK, but I can't run applets in browsers (I may not have installed the JRE).
However, when I install the JRE, it clobbers my JDK as the default runtime. This breaks pretty much everything (Eclipse, Ant) - as they require a server JVM.
There's no JAVA_HOME environment variable these days - it just seems to use some registry magic (setting the system path is of no use either). Previously, I've just uninstalled the JRE after I've used it to restore the JDK. This time I want to fix it properly.
This also manifests itself with the jre autoupdater - once upon a time, I had a working setup with the JDK and JRE, but it updated and bust everything.
This is a bit of a pain on Windows. Here's what I do.
Install latest Sun JDK, e.g. 6u11, in path like c:\install\jdk\sun\6u11, then let the installer install public JRE in the default place (c:\program files\blah). This will setup your default JRE for the majority of things.
Install older JDKs as necessary, like 5u18 in c:\install\jdk\sun\5u18, but don't install the public JREs.
When in development, I have a little batch file that I use to setup a command prompt for each JDK version. Essentially just set JAVA_HOME=c:\jdk\sun\JDK_DESIRED and then set PATH=%JAVA_HOME%\bin;%PATH%. This will put the desired JDK first in the path and any secondary tools like Ant or Maven can use the JAVA_HOME variable.
The path is important because most public JRE installs put a linked executable at c:\WINDOWS\System32\java.exe, which usually overrides most other settings.
I have patched the behaviour of my eclipse startup shortcut in the properties dialogue
from
"E:\Program Files\eclipse\eclipse.exe"
to
"E:\Program Files\eclipse\eclipse.exe" -vm "E:\Program Files\Java\jdk1.6.0_30\bin"
as described in the Eclipse documentation
It is a patch only, as it depends on the shortcut to fix things...
The alternative is to set the parameter permanently in the eclipse initialisation file.
I just had that problem (Java 1.8 vs. Java 9 on Windows 7) and my findings are:
short version
default seems to be (because of Path entry)
c:\ProgramData\Oracle\Java\javapath\java -version
select the version you want (test, use tab completing in cmd, not sure what those numbers represent), I had 2 options, see longer version for details
c:\ProgramData\Oracle\Java\javapath_target_[tab]
remove junction/link and link to your version (the one ending with 181743567 in my case for Java 8)
rmdir javapath
mklink /D javapath javapath_target_181743567
longer version:
Reinstall Java 1.8 after Java 9 didn't work. The sequence of installations was jdk1.8.0_74, jdk-9.0.4 and attempt to make Java 8 default with jdk1.8.0_162...
After jdk1.8.0_162 installation I still have
java -version
java version "9.0.4"
Java(TM) SE Runtime Environment (build 9.0.4+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)
What I see in path is
Path=...;C:\ProgramData\Oracle\Java\javapath;...
So I checked what is that and I found it is a junction (link)
c:\ProgramData\Oracle\Java>dir
Volume in drive C is OSDisk
Volume Serial Number is DA2F-C2CC
Directory of c:\ProgramData\Oracle\Java
2018-02-07 17:06 <DIR> .
2018-02-07 17:06 <DIR> ..
2018-02-08 17:08 <DIR> .oracle_jre_usage
2017-08-22 11:04 <DIR> installcache
2018-02-08 17:08 <DIR> installcache_x64
2018-02-07 17:06 <JUNCTION> javapath [C:\ProgramData\Oracle\Java\javapath_target_185258831]
2018-02-07 17:06 <DIR> javapath_target_181743567
2018-02-07 17:06 <DIR> javapath_target_185258831
Those hashes doesn't ring a bell, but when I checked
c:\ProgramData\Oracle\Java\javapath_target_181743567>.\java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)
c:\ProgramData\Oracle\Java\javapath_target_185258831>.\java -version
java version "9.0.4"
Java(TM) SE Runtime Environment (build 9.0.4+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)
so to make Java 8 default again I had to delete the link as described here
rmdir javapath
and recreate with Java I wanted
mklink /D javapath javapath_target_181743567
tested:
c:\ProgramData\Oracle\Java>java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)
** update (Java 10) **
With Java 10 it is similar, only javapath is in c:\Program Files (x86)\Common Files\Oracle\Java\ which is strange as I installed 64-bit IMHO
.\java -version
java version "10.0.2" 2018-07-17
Java(TM) SE Runtime Environment 18.3 (build 10.0.2+13)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.2+13, mixed mode)
After many attempts, I found the junction approach more convenient. This is very similar on how this problem is solved in linux.
Basically it consists of having a link between c:\tools\java\default and the actual version of java you want to use as default in your system.
How to set it:
Download junction and make sure to put it in your PATH
environment variable
Set your environment this way:
- PATH pointing to ONLY to this jre c:\tools\java\default\bin
- JAVA_HOME pointing to `c:\tools\java\default
Store all your jre-s in one folder like (if you do that in your Program FIles folder you may encounter some
C:\tools\Java\JRE_1.6
C:\tools\Java\JRE_1.7
C:\tools\Java\JRE_1.8
Open a command prompt and cd to C:\tools\Java\
Execute junction default JRE_1.6
This will create a junction (which is more or less like a symbolic link in linux) between C:\tools\java\default and C:\tools\java\JRE_1.6
In this way you will always have your default java in c:\tools\java\default.
If you then need to change your default java to the 1.8 version you just need to execute
junction -d default
junction default JRE_1.8
Then you can have batch files to do that without command prompt like
set_jdk8.bat
set_jdk7.bat
As suggested from #СӏаџԁеМаятіи
EDIT: From windows vista, you can use mklink /J default JRE_1.8
I simply install all the versions of JDK I need and the latest installed becomes default, so I just reinstall the one I want to be default if necessary.
I have several JDK (1.4, 1.5, 1.6) installed in C:\Java with their JREs. Then I let Sun update the public JRE in C:\Program Files\Java.
Lately there is an improvement, installing in jre6. Previously, there was a different folder per new version (1.5.0_4, 1.5.0_5, etc.), which was taking lot of space
an alterable way to run an .jar app is create an .bat cmd for it.
for example, you have jre10 and jre8 installed on your pc,and jre10 is your default jre.
but your jar is specified to work with jre8,following cmd will work:
"C:\Program Files\Java\jre1.8.0_181\bin\java.exe" -jar JabRef-4.3.1.jar
Need to remove C:\Program Files (x86)\Common Files\Oracle\Java\javapath from environment and replace by JAVA_HOME which is works fine for me
Stacked by this issue and have resolved it in 2020, in Windows 10. I'm using Java 8 RE and 14.1 JDK and it worked well until Eclipse upgrade to version 2020-09. After that I can't run Eclipse because it needed to use Java 11 or newer and it found only 8 version. It was because of order of environment variables of "Path":
I suppose C:\Program Files (x86)\Common Files\Oracle\Java\javapath is path to link to installed JRE exe files (in my case Java 8) and the issue was resolved by move down this link after %JAVA_HOME%, what leads to Java 14.1/bin folder.
It seems that order of environment variables affects order of searched folders while executable file is requested.
Thanks for your comment or better explanation.

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