Eclipse can't find Java, Java not installed - java

I was following an online tutorial on how to delete JVM 6 and install JVM 7 to be able to run eclipse on my Mac running OS X 10.9.2. First I installed the latest JDK.
I was instructed to type the following commands to delete JVM 6.
sudo rm -rf /System/Library/Java/JavaVirtualMachines/
sudo rm /private/var/db/receipts/com.apple.pkg.JavaForMacOSX*
sudo emacs /Library/Receipts/InstallHistory.plist
Then, I set the symlinks for java 7, with these commands.
sudo rm /usr/bin/java
sudo ln -s /Library/Java/JavaVirtualMachines/jdk1.7.0_60.jdk/Contents/Home/bin/java /usr/bin/java
This should be it. Now my computer does not have any version of Java on it:
the command "java -version" responds with "java: command not found"
I also cannot direct to the folder with cd Library/Java responding with "Folder does not exist", however I can browse to that folder manually.
Can someone please assist me in getting Java 7 running on my computer so I can use eclipse.
Any help much appreciated and keep in mind I'm a Mac newb.
this is the tutorial i followed:
http://www.cc.gatech.edu/~simpkins/teaching/gatech/cs2340/guides/java7-macosx.html

Did you change the PATH variable to point to the newer version?
/usr/libexec/java_home is the starting point for switching java versions on the command line. Check out this post to understand how to handle different java versions on the Mac.

I think that the folder still exists but executables didn't existe because anh version of Java is installed.
Normally you have just to download the jdk or jre on oracle web site and run the package downloaded

Related

Netbeans is not getting installed in my Mac, it says JDK not found, though JDK is installed in the same

Error: Failure while executing the commands mentioned below:-
/usr/bin/sudo -E -- env LOGNAME=ajaygautam USER=ajaygautam USERNAME=ajaygautam /usr/sbin/installer -pkg /usr/local/Caskroom/netbeans/8.2/NetBeans\ 8.2.pkg -target / exited with 1.
Here's the output:
installer: Error - NetBeans IDE cannot be installed. Java (JRE) found on your computer but JDK 8 or newer is required. Please download and install the latest update of JDK 8 from http://www.oracle.com/technetwork/java/javase/downloads/index.html and restart NetBeans installation.
Would someone in tracing out the issue above? I'm not able to install NetBeans 8.2 package in my Mac.
I got the same problem and could to fix it with brew.
firstly install java JDK https://www.oracle.com/java/technologies/javase-downloads.html then run this in your terminal:
brew install netbeans
it will install the latest version of netbeans.
Download OpenJDK from Archived OpenJDK GA Releases.
This will give you a file such as openjdk-9.0.4_osx-x64_bin.tar. Extract the tar file and copy it to the correct place in your machine.
tar -xf openjdk-9.0.4_osx-x64_bin.tar
sudo cp -r jdk-12.0.2.jdk /Library/Java/JavaVirtualMachines/
Now you can run the Netbeans installer.
i just install using brew
brew install netbeans
and now i can use the latest 12.4
The following steps are used to install NetBeans on MacOS:-
1) Download the Latest version
In order to install NetBeans on MacOS, we have to download the latest version of NetBeans by visiting its official website I.e. https://netbeans.org/downloads/
2) Mount the disk image file
The dmg file which is downloaded from the official website of NetBeans is to be mounted to an installer. This can be done with the following command:
$ hdiutil mount Downloads/netbeans-8.2-macosx.dmg
3) Install the file
The file is mounted to the volumes directory which contains a package file (.pkg) which is installable by using the installer command. The command needs superuser privileges for which, sudo is used.
$ sudo installer -pkg Volumes/ NetBeans\ 8.2/NetBeans\ 8.2.pkg -target /
The file will be installed to the target root which is mentioned while installing the file.
4) Unmount the file
After the completion of installation process, we need to unmount the installer. This can be done by using the option Unmount with hdiutil command.
$ hdiutil unmount /Volumes/NetBeans\ 8.2
Well, we have done with the installation process of NetBeans 8.2 on MacOS.
Actually, java_home is in
/System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java_home
but in my case, java_home was in the next location i.e
/System/Library/Frameworks/JavaVM.framework/Versions/A/Commands/java_home
I deleted my java_home from /usr/libexec/java_home by root user
added new java_home in /usr/libexec by following command
sudo ln -s /System/Library/Frameworks/JavaVM.framework/Versions/A/Commands/java_home /usr/libexec/.
For some reason, some Netbeans versions for Mac OS do not detect the JDK contained in JRE. For proper installation and running the application, you must have Java for Mac OS installed previously. https://www.java.com/es/download/
Install The Lates Version ONLY which is 12.1 as of now!
https://netbeans.apache.org/download/nb121/nb121.html

How to uninstall JDK on Mac OS?

Folks - I am facing challenges while trying to uninstall JDK from my MAC (macOS High Sierra Version 10.13.4 - 17E199). I have two JDK instances installed and I want to uninstall both of them.
I am following the steps listed on this page: https://docs.oracle.com/javase/8/docs/technotes/guides/install/mac_jdk.html
I am trying to run this command in the /Library/Java/JavaVirtualMachines directory which throws an error that I do not have the permission.
rm -rf jdk1.8.0_06.jdk
I am the administrator of the machine and am not sure what more permission do I need. I have made attempts as the admistrator and as the root user with no success.
Please share your thoughts on this.
From the official Oracle manual.
Navigate to /Library/Java/JavaVirtualMachines and remove the directory whose name matches the following format:
/Library/Java/JavaVirtualMachines/jdkmajor.minor.macro[_update].jdk
For example, to uninstall 8u6:
%rm -rf jdk1.8.0_06.jdk
Do not attempt to uninstall Java by removing the Java tools from /usr/bin. This directory is part of the system software and any changes will be reset by Apple the next time you perform an update of the OS.
To remove system files you need to add sudo before rm -rf command.
For MacOS - Big Sur | Using Terminal
I was able to remove OpenJDK as per information provided in below link.
Site Link
If you want to remove JDK from mac you can use the following command:
cd /Library/Java/JavaVirtualMachines/
and then use sudo to remove the jdk because you need root permissions to delete jdk from /Library/Java/JavaVirtualMachines/.
/Library/Java/JavaVirtualMachines/ is owned by root.
sudo rm -rf jdk1.8.0_06.jdk
https://installvirtual.com/uninstall-java-8-mac-os-x/
This answer is correct for JDK 8, but it would be nice to point out that Oracle provides different instructions for each release of the JDK. The link structure changes slightly for some versions, but generally you can go to https://docs.oracle.com/en/java/javase, select your JDK release, and look for the "Install Guide" link in the Overview group.
For example:
JDK 9
JDK 10
JDK 11
Also, the files in /usr/bin are not part of the JDK, so you don't really want to remove them. On a system that has never had the JDK installed:
$ ls -l /usr/bin/java
lrwxr-xr-x 1 root wheel 74 Sep 27 17:08 /usr/bin/java -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java
$ java -version
No Java runtime present, requesting install.
Apparently macOS includes a baseline version of the JDK, where each command is a stub that just prints this message and pops up a dialog in the GUI.

How to uninstall Java 9 on macOS Sierra

I'm having trouble removing Java 9 from my macOS Sierra system.
I accidentally installed Java 9, instead of Java 8, so now all my Eclipse projects give me these warnings: Build path specifies execution environment JavaSE-1.8. There are no JREs installed in the workspace that are strictly compatible with this environment.
I have used the following guide, but it did not work. Here is my command output when running java -version from the command line:
java version "9"
Java(TM) SE Runtime Environment (build 9+181)
Java HotSpot(TM) 64-Bit Server VM (build 9+181, mixed mode)
for macOS high sierra removing java 9:
delete the java folder you find in the dir shown to you after executing:
/usr/libexec/java_home -V
use "Go to" in finder and copy and paste the dir to get there
There are two commands which are very simple and useful. If you want to keep multiple versions simply set JAVA_HOME to version you want to use.
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_(version you want to use).jdk/Contents/Home
Example--> export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home
Else in addition to above command remove/uninstall additional jdk version from your system with below command.
sudo rm -rf /Library/Java/JavaVirtualMachines/jdk-(version you want to remove).jdk/
Example --> sudo rm -rf /Library/Java/JavaVirtualMachines/jdk-9.0.4.jdk/
Please refer below github link for additional details -->
https://gist.github.com/schnell18/bcb9833f725be22f6acd01f94b486392
Thanks
On MacOS you can list what JDKs you have installed and where they are installed to with:
/usr/libexec/java_home -V
If you want to select one of the installed JDKs to be used as default, you can do:
/usr/libexec/java_home -v 1.8
Verify which is now default with java -version.
You can manually add the location of other installed JREs in Eclipse via Preferences / Java / Installed JREs , press Add, and then point it to one of the locations should with the -V option above. You can then check it to select which is default for your projects.
After viewing which Java Virtual Machines I had on my computer using the following command:
ls /Library/Java/JavaVirtualMachines
I realized no additional JDK's would appear after using the Java 8 installer (besides Java 9). When doing further research, it turns out I had installed the other version that is not a SE development kit and it was just working in web browsers, not for the terminal.
For anyone having the same issue, make sure you use the Java SE Development Kit 8.
Uninstall Oracle Java using the Terminal:
Note: To uninstall Java, you must have Administrator privileges and execute the remove command either as root or by using the sudo tool.
Remove one directory and one file (a symlink), as follows:
Click on the Finder icon located in your dock
Click on the Utilities folder
Double-click on the Terminal icon
In the Terminal window Copy and Paste the commands below:
sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin
sudo rm -fr /Library/PreferencePanes/JavaControlPanel.prefPane
sudo rm -fr ~/Library/Application\ Support/Java
Do not attempt to uninstall Java by removing the Java tools from /usr/bin. This directory is part of the system software and any changes will be reset by Apple the next time you perform an update of the OS.
Source:https://www.java.com/en/
I believe the problem is navigating to the correct directory... Once you are where you are supposed to be you can run the sudo commands to remove whichever versions of java you want to remove.
First, run the command in the terminal to determine which version of Java you are running,
java -version
then you can navigate to pesky version of java that you intend to delete by using the following command:
cd /Library/Java/JavaVirtualMachines
then once you see are in the JavaVirtualMachines path, type in ls to see what versions of Java you have installed,
ls
and finally when you know which version or versions of Java you want to uninstall:
sudo rm -rf jdk-10.0.1.jdk #or whichever version you want to delete
I know that you've asked about how to uninstall the java version. But, I think it's important how to manage your Java version in a very good way.
For me, the best way is using SDKMan, a very nice tool for managing you Development tools like Java.
Here you can learn more about it: http://sdkman.io/
You can install your Java version as follow:
$ sdk install java
You can install others tools like Scala:
$ sdk install scala 2.12.1
Uninstall your tools very easy:
$ sdk uninstall java 9
And so on. Hope this helps you in future installation of your development tools.

Cant run java program on raspberry Pi [duplicate]

This question already has an answer here:
JavaFx Ensemble on Raspberry pi
(1 answer)
Closed 7 years ago.
I have downloaded the latest OS for the pi from here http://downloads.raspberrypi.org/raspbian_latest
Then i have downloaded the latest Java JDK to run my JavaFX application from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html and selected the Hard Flat v6/v7 file.
I have transferred and unzipped the JavaJDK onto my Pi.
Now if i execute this command on my local machine, my application starts
Java -jar program_name.jar
But if i run the same command on the Pi, i get an error saying
Could not find or load main class application.Main
If i change the .jar file into a .zip, i can clearly see a directory called application, and file called Main.class
So why is my program working on my (windows 10) machine, whether i run it from eclipse or the command line, but not on the raspberry Pi?
To install the Java Runtime Environment (JRE) run the following command:
sudo apt-get install openjdk-7-jre
This installs the Java JRE (Java Runtime Environment) which will allow you to run applications written in Java.
To install the JDK run the command:
sudo apt-get install openjdk-7-jdk
This allows you to compile Java applications to bytecode.
If you want the Oracle Java VM, which is a lot faster (optimized for embedded arm CPUs) and is also a developer preview (applications maybe buggy or crash) until some time into the future. Instead of the above instructions you need to download the file called Oracle JDK 8 (with JavaFX) for ARM Early Access on the Oracle Java 8 download page.
Remember to download the Oracle Java system on your Pi, or you won't be able to install it.
To install the Oracle Java System:
sudo tar zxvf jdk-8-ea-b36e-linux-arm-hflt-*.tar.gz -C /opt
sudo update-alternatives --install "/usr/bin/java" "java" "/opt/jdk1.8.0/bin/java" 1
sudo update-alternatives for other commands if needed (e.g. javac).
java -version
Then it is all installed.
Another thing, if you have more then one Java runtime installed you have to check which version you use with the command java -version. If the output is:
java version 1.5.0 gij (GNU libgij)
Then you are using another java runtime. You can resolve the issue by running
sudo update-alternatives --config java
and choosing the OpenJDK or Oracle option.

How to fix error: could not find the required version of the Java(TM) 2 runtime environment in '(null)'

I have researched this and none of the solutions that I have seen have fixed my error.
What is happening is I tried to install Java EE version got the above error and then found out that I must install Java SE first. So I installed Java SE and set the JAVA_HOME variable to C:\Program Files\Java\jdk1.8.0 which is where I installed my JDK. I also put C:\Program Files\Java\jdk1.8.0\bin in my PATH variable. Still not working. I also tried the JAVA_HOME variable with C:\Program Files\Java\jdk1.8.0\bin and that didn't work. I also tried installing without the PATH variable being updated to where I put my JDK.
I'm really getting confused as to why this is happening. I've had Java before and I don't recall having this much trouble installing it.
PS I don't install from the command line I just click the download icon in Firefox and then click the download.
Try running the installer at your commandline and pass the path of the JRE instead of the JDK.
For Example:
java_ee_sdk7-windows.exe -j "C:\Program Files\Java\jre8"
I had the exact same problem and even downloading the version without JDK didn't help!
I simply installed it from the terminal with passing the JRE For Example:
java_ee_sdk7-windows.exe -j "C:\Program Files\Java\jre7"
and it worked like a charm!
I had the same problem but an additional step was required in order to install using the command line. In the command window (on my Windows 10 laptop) I had to use:
cmd /d
to tell the cmd window to ignore registry AutoRun commands before the java installation executable would run. After using cmd /d, and changing to the directory where the .exe file was at, the following worked:
java_ee_sdk-6u4-jdk7-windows-x64.exe -j "%JAVA_HOME%"
Where JAVA_HOME is a system environment variable pointing to an existing JDK installation (C:\Program Files\Java\jdk1.8.0_65).
Uninstall everything, all of it.
Then go to your Program Files folder (and (x86) folder if on a 64bit Windows) and physically remove any Java folders.
Reinstall Java SE and then the EE packages. Sometimes Windows appears to get a bit confused and you need to help it figure out what to do.
If you want to uninstall, go to the glassfish folder and open the command prompt, then type:
uninstall.exe -j <The path to your JRE>
These points may be helpful.
java EE SDK7 contains glassfish v4.0 and it compatible with JDK6 and JDK7.
java EE SDK8 contains glassfish v5.0, it compatible with only JDK7 and JDK8, not JDK 9 or beyond.
So environment variable JAVA_HOME has to point to the root directory of one of the mentioned JDK. and %JAVA_HOME%\bin should be added to environment variable path
Despite having followed all of the above, setup of java EE SDK7 gets error:
could not find the required version of the Java(TM;
as Bakudan and laf8 said,
open cmd using run, with /d /a options as followed.
cmd /d /a
and next run SDK7-setup with -j option like this command
sdk7.exe -j "%JAVA_HOME%"
note that %JAVA_HOME% enclosed BY ""
This was happening to me when I tried to run the Java EE installer. What I did, was to download from Oracle a Java EE version which didn't include the JDK, because it was already installed in my system. Problem solved!
Open regedit.
goto :HKEY_LOCAL_MACHINE\Software\JavaSoft\Java Runtime Environment\
set CurrentVersion to desired JDK version.
Check JavaHome and RuntimeLib path's for selected jdk version folder
Check JavaHome and RuntimeLib path's for selected jdk version folder
example: "HKEY_LOCAL_MACHINE\Software\JavaSoft\Java Runtime Environment\1.7".
example:
JavaHome=C:\Program Files (x86)\Java\jdk1.7.0_79
RuntimeLib=C:\Program Files (x86)\Java\jdk1.7.0_79\jre\bin\server\jvm.dll
Source: http://tech-read.com/2009/05/19/how-to-solve-error-could-not-find-java-runtime-2-environment-while-opening-an-ide/

Categories

Resources