Usage

Installing an SDK

Latest Stable

Install the latest stable version of your SDK of choice (say, Java JDK) by running the following command:

$ sdk install java

You will see something like the following output:

                                
Downloading: java 21.0.1-tem

In progress...

######################################################################## 100.0%

Installing: java 21.0.1-tem
Done installing!

Now you will be prompted if you want this version to be set as default.

Do you want java 21.0.1-tem to be set as default? (Y/n):

Answering yes (or hitting enter) will ensure that all subsequent shells opened will have this version of the SDK in use by default.

Setting java 21.0.1-tem as default.

Specific Version

Need a specific version of an SDK? Simply qualify the version you require:

$ sdk install scala 3.3.1

All subsequent steps same as above.

Install Local Version(s)

Using a snapshot version? Already have a local installation? Setup a local version by specifying the path to the local installation:

$ sdk install groovy 3.0.0-SNAPSHOT /path/to/groovy-3.0.0-SNAPSHOT

$ sdk install java 17-zulu /Library/Java/JavaVirtualMachines/zulu-17.jdk/Contents/Home

Note that the local version name (3.0.0-SNAPSHOT and 17-zulu in the examples above) must be a unique name which is not already in the list of available version names.

Remove Version

Remove an installed version.

$ sdk uninstall scala 3.3.1

Note that removing a local version will not remove the local installation.

List Candidates

To get a listing of available Candidates:

$ sdk list

This will render a searchable alphabetic list with name, current stable default version, website URL, description and easy install command for each Candidate. The output is piped to less so standard keyboard shortcuts may be used with q to exit.


================================================================================
Available Candidates
================================================================================
q-quit                                  /-search down
j-down                                  ?-search up
k-up                                    h-help
--------------------------------------------------------------------------------
...
--------------------------------------------------------------------------------
Java (21.0.1-tem)        https://projects.eclipse.org/projects/adoptium.temurin/

Java Platform, Standard Edition (or Java SE) is a widely used platform for
development and deployment of portable code for desktop and server environments.
Java SE uses the object-oriented Java programming language. It is part of the
Java software-platform family. Java SE defines a wide range of general-purpose
APIs – such as Java APIs for the Java Class Library – and also includes the Java
Language Specification and the Java Virtual Machine Specification.

$ sdk install java
--------------------------------------------------------------------------------
...

List Versions

To get a listing of Candidate Versions:

$ sdk list groovy

This will result in a list view showing the available, local, installed and current versions of the SDK.


================================================================================
Available Groovy Versions
================================================================================
> * 2.4.4                2.3.1                2.0.8                1.8.3
    2.4.3                2.3.0                2.0.7                1.8.2
    2.4.2                2.2.2                2.0.6                1.8.1
    2.4.1                2.2.1                2.0.5                1.8.0
    2.4.0                2.2.0                2.0.4                1.7.9
    2.3.9                2.1.9                2.0.3                1.7.8
    2.3.8                2.1.8                2.0.2                1.7.7
    2.3.7                2.1.7                2.0.1                1.7.6
    2.3.6                2.1.6                2.0.0                1.7.5
    2.3.5                2.1.5                1.8.9                1.7.4
    2.3.4                2.1.4                1.8.8                1.7.3
    2.3.3                2.1.3                1.8.7                1.7.2
    2.3.2                2.1.2                1.8.6                1.7.11
    2.3.11               2.1.1                1.8.5                1.7.10
    2.3.10               2.1.0                1.8.4                1.7.1

================================================================================
+ - local version
* - installed
> - currently in use
================================================================================

Use Version

Choose to use a given version in the current terminal:

$ sdk use scala 3.3.1

It is important to realise that this will switch the candidate version for the current shell only. To make this change permanent, use the default command instead.

Default Version

Chose to make a given version the default:

$ sdk default scala 3.3.1

This will ensure that all subsequent shells will start with version 3.3.1 in use.

Current Version(s)

To see what is currently in use for a Candidate:


$ sdk current java
Using java version 21.0.1-tem

To see what is currently in use for all Candidates:


$ sdk current
Using:
groovy: 4.0.16
java: 21.0.1-tem
scala: 3.3.1

Env Command

Want to switch to a specific JDK or SDK every time you visit a project? This can be achieved through an .sdkmanrc file in the base directory of your project. This file can be generated automatically by issuing the following command:

$ sdk env init

A config file with the following content has now been created in the current directory:

# Enable auto-env through the sdkman_auto_env config
# Add key=value pairs of SDKs to use below
java=21.0.1-tem

The file is pre-populated with the current JDK version in use, but can contain as many key-value pairs of supported SDKs as needed. To switch to the configuration present in your .sdkmanrc file, simply issue the following command:

sdk env

You should see output that looks something like this:

Using java version 21.0.1-tem in this shell.

Your path has now also been updated to use any of these SDKs in your current shell. When leaving a project, you may want to reset the SDKs to their default version. This can be achieved by entering:


$ sdk env clear
Restored java version to 21.0.1-tem (default)

After checking out a new project, you may be missing some SDKs specified in the project's .sdkmanrc file. To install these missing SDKs, just type:


$ sdk env install

Downloading: java 21.0.1-tem

In progress...

######################################################################## 100,0%

Repackaging Java 21.0.1-tem...

Done repackaging...

Installing: java 21.0.1-tem
Done installing!

Do you want to switch SDK versions automatically when you cd into a directory? This can be done by setting the sdkman_auto_env=true in the SDKMAN configuration. Note that this will also reset any project-specific SDKs to their default version when leaving the directory.

Upgrade Version(s)

To see what is currently out of date for a Candidate on your system:


$ sdk upgrade springboot
Upgrade:
springboot (1.2.4.RELEASE, 1.2.3.RELEASE < 3.2.0)

To see what is outdated for all Candidates:


$ sdk upgrade
Upgrade:
gradle (2.3, 1.11, 2.4, 2.5 < 8.5)
grails (2.5.1 < 6.1.0)
springboot (1.2.4.RELEASE, 1.2.3.RELEASE < 3.2.0

SDKMAN! Version

Display the current script and native versions of SDKMAN!:


$ sdk version

SDKMAN!
script: 5.7.0
native: 0.1.3

Offline Mode

Initially called Aeroplane Mode, this allows SDKMAN! to function when working offline. It has a parameter that can be passed toenable or disable the offline mode.


$ sdk offline enable
Forced offline mode enabled.

$ sdk offline disable
Online mode re-enabled!

When operating in offline mode, most commands will still work even though they will operate in a scaled down capacity. An example is the list command, which will only display the currently installed and active version(s):


$ sdk list groovy
------------------------------------------------------------
Offline Mode: only showing installed groovy versions
------------------------------------------------------------
> 2.4.4
* 2.4.3
------------------------------------------------------------
* - installed
> - currently in use
------------------------------------------------------------

The offline mode will also be disabled/enabled automatically when the internet becomes available/unavailable. Naturally, commands that require internet connectivity will not function but give a warning.

Self-Update

Installs a new version of SDKMAN! if available.

$ sdk selfupdate

If no new version is available an appropriate message will be displayed. Re-installation may be forced by passing the force parameter to the command:

$ sdk selfupdate force

Automatic daily checks for new versions of SDKMAN! will also be performed on the behalf of the user.

Update

Periodically SDKMAN! requires a refresh to become aware of new (or removed) candidates. When candidate metadata has potentially grown stale, a warning is displayed with instruction on how to update. By simply running the following command, the candidate cache will be refreshed and new candidates will become available for installation:


WARNING: SDKMAN is out-of-date and requires an update.

$ sdk update
Adding new candidates(s): kotlin

Flush

It should rarely be necessary to flush SDKMAN!'s local state. The flush command helps with this, so you don't need to delete any directories.
Manually deleting directories like the .sdkman/tmp directory will break SDKMAN! Always use the flush command instead!

$ sdk flush

Home

When using SDKMAN in scripts, it is often useful to get the absolute path of where an SDK resides (similar to how the java_home command works on macOS). For this we have the home command.

$ sdk home java 21.0.1-tem
/home/myuser/.sdkman/candidates/java/21.0.1-tem

Help

You can get basic help by running the following command:

$ sdk help

This should render a useful top-level help page. You can add qualifier to this command to get help about a specific sub-command.

$ sdk help install

Configuration

Configuration can be found in the ~/.sdkman/etc/config file. To edit the configuration, the sdk config command may be issued to edit this file in the system editor. The following configurations are available:


# make sdkman non-interactive, preferred for CI environments
sdkman_auto_answer=true|false

# check for newer versions and prompt for update
sdkman_selfupdate_feature=true|false

# disables SSL certificate verification
# https://github.com/sdkman/sdkman-cli/issues/327
# HERE BE DRAGONS....
sdkman_insecure_ssl=true|false

# configure curl timeouts
sdkman_curl_connect_timeout=5
sdkman_curl_continue=true
sdkman_curl_max_time=10

# subscribe to the beta channel
sdkman_beta_channel=true|false

# enable verbose debugging
sdkman_debug_mode=true|false

# enable colour mode
sdkman_colour_enable=true|false

# enable automatic env
sdkman_auto_env=true|false

# enable bash or zsh auto-completion
sdkman_auto_complete=true|false