Is there Ruby Version Manager equivalent for the Java world?
I'm looking for tool which allow me to easily download and install a new JVMs and switch between them. For example:
jvm install <version>
jvm list //will list installed JVMs on my system
jvm use jdk1.6 //will switch my env to jdk 1.6 version, etc.
http://www.jenv.be/ will allow this type of control.
SDKMAN! is a similar tool for the Java ecosystem. Supports various Java versions, Scala, Clojure, Kotlin, Groovy, and build tools like Maven and Gradle.
Works on Mac and Linux, with some mentions of support for Windows depending on how hard you are willing to try :)
If you use Ubuntu you can specify which JVM you want to use via command (works only for JVM installed from apt-get or aptitude)
sudo update-alternatives --config java
Or by setting JAVA_HOME. Here is good tutorial:
http://vietpad.sourceforge.net/javaonlinux.html
For the sake of completeness, there are two more - jabba (of which I am the author; written in Go and designed after nvm/gvm/rvm) and jenv (not to confuse with jenv.be; doesn't support installation from oracle but can install from a custom zip).
With JVMs, if you need to switch between them you just need to use a batch file (or powershell script) to manage the classpath and JVM path. You don't need to rely on the system default JVM path and instead just allow your app to point to whatever JVM you like by changing classpath and JVM path environment in the shell that runs the JVM.
For programs that are getting Java location from the Registry, in theory you could use a batch script to update that also.
In this respect Java is way easier than "Ruby version manager".
As it is not (yet) in the list of possibilities, there's also asdf.
asdf does not only provide version management for java, it has plugins for ~400 different languages and tools by default, you can find more on github, or create your own.
Here is an example how to setup a new install (you can also install completion so you don't have to list the versions first). The java plugin is added, a specific version (there are versions for adoptopenjdk, corretto, dragonwell, graalvm, liberica, mandrel, microsoft, openjdk, oracle, sapmachine, semeru, temurin, trava, zulu) is installed and configured to be the global (or local version) to use:
asdf plugin-add java # Add java Plugin
asdf list-all java # List all available java versions
asdf install java openjdk-18 # Install specific jdk version
asdf install java openjdk-17 # Install another jdk version
asdf global java openjdk-18 # Set the global jdk version
asdf local java openjdk-17 # Set the local version for calls from the current directory
asdf uses a file in $HOME/.tool-versions to configure the global selected version. If you call any tool in a directory that has a .tool-versions file with a different version, that one is used (defined with asdf local …).
The trick is to use update-java-alternatives (from the java-common package). The update-alternatives command will not update every one of the symbolic links for various java /bin executables, which is why update-java-alternatives is better.
So to go for OpenJDK 6 to 7, use update-java-alternatives -l to get a list of Java alternatives and then used sudo update-java-alternatives -s java-1.7.0-openjdk-amd64 to switch the JDK.
CAVEAT: The command above might throw the following errors,
update-alternatives: error: no alternatives for mozilla-javaplugin.so.
update-java-alternatives: plugin alternative does not exist:
/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/IcedTeaPlugin.so
This is because the openjdk plugin is not installed by default. To fix run sudo apt-get install icedtea-7-plugin and rerun update-java-alternatives.
Related
Could someone please let me know the steps to install Java on a Mac.
I did brew install java
I get this
Warning: openjdk 17.0.1 is already installed and up-to-date.
To reinstall 17.0.1, run:
brew reinstall openjdk
If I do java -version, I get this.
openjdk version "13.0.8" 2021-07-20
If I have navigate to /Library/Java, I have 2 empty directories.
Where is java 17 installed??
In 2023, even if you can use just brew..
brew install openjdk#17
Java will be installed here:
/usr/local/opt/openjdk#17/bin/java
For the system Java wrappers to find this JDK, symlink it with:
sudo ln -sfn /usr/local/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk
...give a try to sdkman, it's far better than brew
curl -s "https://get.sdkman.io" | bash
then open a new shell and try list to see what you could install ;-)
sdk list java
At time of writing you could use:
sdk install java 17.0.4.1-tem
Java will be installed here:
/Users/freedev/.sdkman/candidates/java/17.0.4.1-tem
Java doesn't mind if you install multiple versions. This is often required; java is not backwards compatible (it tries to change little, but e.g. the java8 to java9 transition broke a ton of stuff, much of it needless and much of it not reasonably expectable or fixable by libraries and apps, so a bunch of java apps and libraries only run on java8 - just an example).
So, yes, you have installed JDK17. Also, yes, if you just run java without specifying which one you want, you so happen to get java13 here.
To see all installed javas, you can run:
/usr/libexec/java_home -V
to 'override', you can use something like (depends on which shell you're using on your mac):
export JAVA_HOME=`/usr/libexec/java_home -v 17`
(the backticks mean: Run this then take the output of it and treat that as the 'value' of the expression. here, assign it to the JAVA_HOME env var. -v 17 requests a path to java 17. The -V option lists all and is meant for your eyeballs, not for scripts. The -v option is mostly for scripting, and that's how we're using it here).
JAVA_HOME decides which java is used by some things, but the java you get when you just type java is /usr/bin/java, and that executable is actually just a wrapper that picks a java to run from amongst all installed versions. It uses JAVA_HOME to decide which java to actually run. There are wrappers for all the common commands (javac, too). You can always run e.g. which javac to see what that actually runs; you probably see /usr/bin/javac. Everything in /usr/bin is one of these wrapper thingies that looks at JAVA_HOME and then runs the binary it finds there.
To specify version 17
brew install openjdk#17
Later I add create a link:
sudo ln -sfn /usr/local/opt/openjdk#17/libexec/openjdk.jdk \
/Library/Java/JavaVirtualMachines/openjdk-17.jdk
And use jenv to control which java version to use
To used the version installed by homebrew rather than the one installed by the OS you can get detailed information from homebrew by typing
brew info java
Currently it states
For the system Java wrappers to find this JDK, symlink it with
sudo ln -sfn /opt/homebrew/opt/openjdk/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk.jdk
openjdk is keg-only, which means it was not symlinked into /opt/homebrew,
because macOS provides similar software and installing this software in
parallel can cause all kinds of trouble.
If you need to have openjdk first in your PATH, run:
echo 'export PATH="/opt/homebrew/opt/openjdk/bin:$PATH"' >> ~/.zshrc
For compilers to find openjdk you may need to set:
export CPPFLAGS="-I/opt/homebrew/opt/openjdk/include"
For Homebrew, the package that installs the new AdoptOpenJDK is named as temurin. So you need to use below command:
brew install --cask temurin17
If you get any error like temurin cask not available then update brew using below commands:
brew update
brew tap homebrew/cask-versions
To switch quickly between different versions of java add the entries in bashrc as per your jdk versions like:
alias j8="export JAVA_HOME=`/usr/libexec/java_home -v 1.8`; java -version"
alias j17="export JAVA_HOME=`/usr/libexec/java_home -v 17`; java -version"
Steps to install
You asked:
let me know the steps to install Java on a Mac.
Download an installer free-of-cost from vendors such as Adoptium, Azul Systems, Bellsoft, Amazon, Oracle, Microsoft, SAP, and others.
Run installer app.
Quit the installer app when done.
Verify installation by typing on a command-line in Terminal.app:java --version
Delete installer app that you downloaded.
Configure your IDE to use that new Java implementation you installed.
Java location
You asked:
Where is java 17 installed??
/Library/Java/JavaVirtualMachines/
In the Finder, choose Go > Go to Folder, and paste /Library/Java/JavaVirtualMachines/.
Note that this is not the Library folder within your home folder. We are not referring to /Users/your_user_name/Library/…. We are referring to the root Library folder that applies across all the user accounts on this Mac.
You said:
I did brew install java
No need for the Homebrew package manager. If you already enjoy using the brew tool, proceed. But if new to Homebrew, skip it if your only goal is to install Java. Just use an installer for Java as you would for many Mac apps.
JavaFX
You added a tag for javafx.
Be aware that for JavaFX, you have two options:
Include the necessary OpenJFX libraries within your development project and within your final app, or …
Use a JDK that includes the JavaFX/OpenJFX libraries.
At least two vendors provide JDK installers that include the JavaFX/OpenJFX libraries:
Azul Systems (ZuluFX)
Bellsoft (LibericaFX)
This answer is specifically if you use Intellij on a Mac
Within IntelliJ, you can use the IDE to add new JDKs of selected versions from common vendors. Instructions for this are here:
Setup the project JDK
When setting up the JDK, you can either:
Select a pre-existing JDK which has been registered with the IDE OR
Use the Add JDK option to add a new JDK which you previously downloaded and installed using the method outlined in Basil's answer OR
Use the Download JDK option to choose a vendor and version of the JDK that the IDE will automatically download, install and make available for selection.
The JDKs installed by Idea will be located in the same location as outlined in Basil's answer for a manual install /Library/Java/JavaVirtualMachines/.
One common issue is that the version of the JDK registered for the project differs from the default version used in the terminal. This can sometimes mean that the app works when run in Idea, then fails when run in the terminal (or, at least that it is executed against a version of the JDK you didn't expect).
To select the version of the JDK to run in the terminal, configure the Java home setting as outlined in rzwitserloot's answer.
export JAVA_HOME=`/usr/libexec/java_home -v 17`
Also, some tools such as the openjfx maven plugin will not use the java version selected in Idea when executing a call to a JDK tool like jlink, but will instead have their own mechanism for finding a JDK to use (e.g. look at JAVA_HOME or use the Maven toolchains plugin). So it is always good to check the JAVA_HOME variable and ensure that it is set to a reasonable value, both for terminal execution and for effective use of Java development tools that may rely on it.
I think that answers here are not fully out of topic, but from my point of view, my case is exactly the same as that of the author. I had already installed java 8, 11, and 13. All of them resides at:
/Library/Java/JavaVirtualMachines/
Nevertheless when I tried to find the path of JDK 17 it resides:
/usr/local/Cellar/openjdk
I use Mac OS Big Sur and the JDK was installed with homebrew
Brew now supports searching old formulae and allowing you to install a specific version. I'm using Homebrew 3.5.2-117-gb941470
Create a local tap: brew tap-new --no-git local/openjdk
Ask Brew to find the formulae of the version you want: brew extract --version 17.0.2 openjdk local/openjdk
Install Java 17 using your new local tap: brew install openjdk#17.0.2
Link the JDK into the MacOS JVM Dir: sudo ln -sfn /usr/local/opt/openjdk#17.0.2/libexec/openjdk.jdk /Library/Java/JavaVirtualMachines/openjdk17.0.2.jdk
Check Java 17 is available: /usr/libexec/java_home -V
Set Java Home: export JAVA_HOME=$(/usr/libexec/java_home -v17)
Check current version of Java is correct...
$ java --version
openjdk 17.0.2 2022-01-18
The following method installs Java without the need for any additional tools or package managers.
Go to https://jdk.java.net/17/ and download the latest macOS archive.
Download the latest Adoptium release for the Java 17 branch by going to https://adoptium.net/temurin/releases/ and be sure to select the tar.gz version.
The archive is either for x64 (Intel CPU) or for AArch64 (Apple Silicon / M1 CPU).
Then, open a Terminal, and extract the downloaded archive to the system path for Java virtual machines:
cd Downloads
tar xzf OpenJDK17U-jdk_aarch64_mac_hotspot_17.0.5_8.tar.gz -C /Library/Java/JavaVirtualMachines
I have to automate a process in which i need to install java on RHEL 7, using rpm package and then update the security jars later on the installed location. Once i execute the java rpm, how would i get the correct installed path? when i execute which java it says /bin/java. However, i need the installation location using shell script.
Here, the actual installation happened at /usr/java/jdk1.7.0_55/jre. I want to get this location. Can some one suggest me how to retrieve this?
The readlink program (part of coreutils, and available on any RHEL version) can resolve symbolic links:
foo=$(readlink -f $(which java))
echo $foo
(You may also have realpath, but perhaps not).
Java RPM packages from Oracle support the 'alternatives' system, which provides the detail you are seeking. For example, after installing a recent JRE, 'alternatives' reports like so:
[user#host ~]$ alternatives --display java
java - status is auto.
link currently points to /usr/java/jre1.8.0_60/bin/java
etc...
The output is relatively friendly for scripting.
After installing two versions of java in rhel how do I point my program to one of those specific java file?
The java files that were installed were:
java-1.7.0-oracle-src-1.7.0.79-1jpp.1.el7_1.x86_64
java-1.8.0-oracle-javafx-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.8.0-oracle-devel-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.8.0-oracle-src-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.7.0-oracle-javafx-1.7.0.79-1jpp.1.el7_1.x86_64
java-1.8.0-oracle-jdbc-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.7.0-oracle-devel-1.7.0.79-1jpp.1.el7_1.x86_64
java-1.7.0-oracle-jdbc-1.7.0.79-1jpp.1.el7_1.x86_64
java-1.8.0-oracle-plugin-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.7.0-oracle-1.7.0.79-1jpp.1.el7_1.x86_64
java-1.8.0-oracle-1.8.0.45-1jpp.2.el7_1.x86_64
java-1.7.0-oracle-plugin-1.7.0.79-1jpp.1.el7_1.x86_64
Do you mean choosing what version of Java to use?
Some Linux distributions rely on update-alternatives tool to control what specific binary to use when multiple versions of it are installed. It works by setting symbolic links. For instance in my system, after installing openjdk, a symbolic link at:
/usr/bin/java
was created linked to the real java binary at:
/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
If update-alternatives is installed in your system, and the installation of Java updated its status correctly, you can choose the version of Java interactively by doing:
sudo update-alternatives --config java
Another approach: simply set JAVA_HOME and/or PATH environment variables right before you execute your command to switch between one or other Java version.
I would like to know which version of java is installed on my ubuntu system.
The java -version command shows:
cmdprompt$ java -version
java version "1.6.0_20"
Java(TM) SE Runtime Environment (build
1.6.0_20-b02)
Java HotSpot(TM) Client VM (build
16.3-b01, mixed mode, sharing)
However the following cmd shows 2 Java versions installed? What are these?
cmdprompt$ ls -l $(type -path -all java)
lrwxrwxrwx 1 root root 22 2010-02-28 14:21 /usr/bin/java -> /etc/alternatives/java
lrwxrwxrwx 1 root root 15 2010-06-29 22:36 /usr/lib/jvm/java-6-sun/bin/java ->
../jre/bin/java
How do I ensure there is ONLY ONE version of JAVA is installed - so that there are no build conflicts?
The alternatives directory contains links pointing to your preferred alternatives. (This makes it really easy to switch between preferred versions.)
To me it looks like you only have one version installed, and that this version is pointed to by /etc/alternatives/java.
How do I ensure there is ONLY ONE version of JAVA is installed - so that there are no build conflicts?
Well, first of all, I doubt that you'll be running into trouble with build-conflicts. But to ensure that you only have one version of java installed, you could list all installed packages called something with java like this:
dpkg --get-selections | grep -i java
and then remove the packages you don't want to have installed, using apt-get remove pkgname.
Ubuntu supports several different possible installations of Java by a common trick, namely symlinks. If you type which java it will tell you that "java" resolves to "/usr/bin/java" (where Java is supposed to be installed), which in turn points to /etc/alternatives/java which is a symlink that is automatically updated via the update-alternatives command. This command may be used to, for example, switch between Sun's Java implementation and the Open JDK version of Java. There won't be any conflicts, since they each occupy distinct locations and have distinct paths, and the symlink (where the system expects to find Java) may be easily updated to switch to whichever one is to be used.
You can use update-alternatives to see which version of Java is currently selected. For example:
sudo update-alternatives -l
The command above will tell you which "alternatives" have been selected for various tools.
I have always had about a dozen version of java installed and I have never got build conflicts. A build should only use one version of Java at a time. All versions of Java 6 are basically compatible so even if you mixed them you wouldn't see an issue.
If you tried to use a class compiled with Java 6 in a Java 5.0 compiler you would get a error which would make it obvious you have a version problem. However, if you set the '-target 1.5' option you can mix Java 5.0 and 6 compilers as well.
In short, I wouldn't worry about it unless you know you have a problem.
I want to install a specific JDK (the latest for example). For this, I went to the JDK download homepage: http://java.sun.com/javase/downloads/index.jsp.
I looked for a Mac version, but I'm a bit surprised to only see downloadable versions for Linux, Windows and Solaris...
Here's the message for Mac:
"Apple Computer supplies their own version of Java. Use the Software
Update feature (available on the Apple menu) to check that you have
the most up-to-date version of Java for your Mac."
OK BUT... when I update Java with Mac I have a JRE and not a JDK...
I don't understand why a JDK version doesn't exist that is easily downloadable/installable (like a jar to unzip?) for Mac...
In a comment under #Thilo's answer, #mobibob asked how to set JAVA_HOME in your .bash_profile on a Mac. Answer:
export JAVA_HOME=`/usr/libexec/java_home`
This will dynamically assign to JAVA_HOME the location of the first JDK listed in the "General" tab of "Java Preferences" utility.
See Apple Technical Q&A 1170: https://developer.apple.com/library/content/qa/qa1170/_index.html
EDIT:
If you prefer parentheses to backticks for command substitution, this also works:
export JAVA_HOME=$(/usr/libexec/java_home)
As the message says, you have to go to Apple, not Sun, for Java on the Mac. As far as I know, Apple JDK 6 is installed by default on Mac OS X 10.6 (Snow Leopard). Maybe you need to install the developer tools from your Mac OS X installation DVD (the dev tools are an optional install from the OS DVD).
See: http://developer.apple.com/java/
NOTE This answer from 16 Oct 2009 is now outdated; you can get the JDK for Mac OS X from the regular JDK download page on Oracle's website now.
For people using any LION OS X 10.7.X
They uploaded Java SE 6 version 1.6.0_26 available here
http://support.apple.com/kb/dl1421
I bought a MacBook Pro yesterday (Mac OS X v10.8 (Mountain Lion)) and there is no JDK installed by default...
As well as javac, I also found it didn't have packages such as SVN installed. It turns out you can get everything from the Apple developer page (you will need to register with your AppleID). SVN is part of the "Command Line Tools" package.
This is what happens on a fresh MacBook:
Hopefully this will help out other newbies like me ;)
The explanation is that JDK is a bit specific and does not contain the library tools.jar. For my development, I need this library and Mac's JDK doesn't provide it:
(Cf. http://developer.apple.com/mac/library/documentation/Java/Conceptual/Java14Development/02-JavaDevTools/JavaDevTools.html)
tools.jar does not exist. Classes usually located here are instead included in classes.jar. Scripts that rely on the existence of tools.jar need to be rewritten accordingly.
It sucks!
The easiest way is to use Homebrew.
Install Homebrew and then:
brew tap caskroom/versions
brew cask install java7
You can list all available versions using the following command:
brew cask search java
Mac comes with the JDK, for more information check:
http://developer.apple.com/mac/library/documentation/Java/Conceptual/Java14Development/02-JavaDevTools/JavaDevTools.html
Compiling with -source 1.5 -target 1.5 (in a JDK 6 environment) will honor only language elements that were in 1.5 and prior. Great. But there were no language changes in 6 anyway. Problem with this approach (on Mac with 1.6) is that using classes that came AFTER 1.5 will still compile because they exist in the rt.jar. So one could run in a 1.5 env and get a class not found exception with no prior warning when compiling. I found this out the hard way with javax.swing.event.RowSorterEvent/Listener. Both entered "Since 1.6" but are not caught with -source 1.5
If you installed brew, cmd below will be helpful:
brew cask install java
As of Mac OS X v10.6 (Snow Leopard), you can run Java 6 in 32-bit mode on either 32-bit or 64-bit Intel processor equipped Macs.
If you cannot upgrade to Snow Leopard, Soy Latte is a pre-compiled version of Java 6 for Intel 32-bit.
There are various tricky issues with having multiple versions of Java (Apple's own Java 6 and Oracle JDK 7 or even 8) on one's Mac OS X system, and using different versions for different applications. I spent some time writing up my experience of my experience of installing and configuring various versions of JDK on Mac OS X 10.9.2.
In 2022, give a try to sdkman, is better than brew
curl -s "https://get.sdkman.io" | bash
then open a new shell and try list to see what you could install ;-)
sdk list java
At time of writing you could use:
sdk install java 17.0.1-tem
Check this awesome tool sdkman to manage your jdk and other jdk related tools with great ease!
e.g.
$sdk list java
$sdk install java <VERSION>
Since most answers are out of date, here's what works as of end of 2018 under the assumption that
You want to install the GPL version of OpenJDK.[0]
You do not want to install Homebrew
In that case, grab the desired version from one the many available, freely usable OpenJDK editions, e.g.:
AdoptOpenJDK
Amazon Corretto (Great for production, includes backports)
Oracle GPLv2 OpenJDK
Some of these include installers, but if not you can do the following. Assuming here version 11.0.1 for Mac. In your favorite shell, run:
tar -xzf openjdk-11.0.1_osx-x64_bin.tar.gz
sudo mv jdk-11.0.1.jdk /Library/Java/JavaVirtualMachines
# Fix owner and group
sudo chown -R root:wheel /Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk
# (Optional) Check if the new JDK can be found
/usr/libexec/java_home
=> /Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk/Contents/Home
[0] Note that the Oracle branded JDK has significant licensing restrictions allowing you its use basically only for testing, i.e., not for production. If you do not have a support agreement with Oracle, then it seems risky to me to use their JDK, especially since the differences to OpenJDK are minimal.
Edit: added more choices
I think this other Stack Overflow question could help:
How to get JDK 1.5 on Mac OS X
It basically says that if you need to compile or execute a Java application with an older version of the JDK (for example 1.4 or 1.5), you can do it using the 1.6 because it is backwards compatible. To do it so you will need to add the parameter -source 1.5 and/or -target 1.5 in the javac options or in your IDE.
JDK is the Java Development Kit (used to develop Java software).
JRE is the Java Runtime Environment (used to run any .jar file 'Java software').
The JDK contains a JRE inside it.
On Windows when you update Java, it updates the JRE automatically.
On Mac you do not have a JRE separated you have it, but inside the JDK, so when you update Java it will update your JRE which is inside your JDK;
it doesn't install an JDK for you. You need to get it from somewhere else.
As a rule you cannot install other versions of Java on a Mac than those provided by Apple through Software Update. If you need Java 6 you must have a 64-bit Intel computer. You should always have Java 5 and 1.4 and perhaps 1.3 installed if you have at least OS X 10.4.
If you have VERY much elbow grease and is willing to work with beta software you can install the OpenJDK under OS X, but I don't think you want to go there.