jenv

Set Java path for MATLAB

Since R2021b

Syntax

jenv(version)

jenv("-clear")

jenv("-allusers",___)

je = jenv

je = jenv(___)

Description

jenv(version) sets the Java^® path for MATLAB^® to a Java version on your system or the version in a specified folder. For supported version information, see Versions of OpenJDK Compatible with MATLAB by Release. For more information, see Configure Your System to Use Java.

This function sets the path for all future MATLAB sessions but does not change the path for other applications on your computer.

jenv("-clear") removes the JRE™ configuration for an individual user. Use this option after installing the MATLAB Support for OpenJDK^® add-on. (since R2026a)

When you clear the JRE configuration, MATLAB looks for the JRE in this order:

1. Location of the MATLAB Support for OpenJDK add-on.

2. Depending on your operating system:

   • For Windows^® and Linux^®, the version of Java shipped with MATLAB.

   • For Apple silicon, the system-installed Java.

jenv("-allusers",___) configures the JRE for all users of a MATLAB installation. Use this syntax with any of the input argument combinations in previous syntaxes.

je = jenv returns information about the current Java environment as a JavaEnvironment object.

je = jenv(___) returns information about the Java environment after making the specified Java configuration changes. Use this syntax with any of the input argument combinations in previous syntaxes.

Examples

Use Specific Version of Installed Java

Use the version of Java installed at C:\Program Files\Java\jre1.8.0_202.

jenv("C:\Program Files\Java\jre1.8.0_202")

Restart MATLAB to use the updated path.

Then, verify the version.

version -java

Use System Java for All Users

If you have administrator privileges, you can specify the Java version for all users.

Start MATLAB with administrator privileges. Specify for all users to use the version of Java on their system.

jenv -allusers system

Restart MATLAB to use the specified version.

Then, verify the version.

version -java

Input Arguments

version — Java version

string scalar | character vector

Java version, specified as a string scalar or character vector that contains one of these values:

• "system" — The function searches your system for Java version 8. If version 8 is not found, the function searches for version 11, then for version 17. The search is based on platform.

  • Windows platforms:

    1. java -version system command

    2. Registry entries

  • Linux platforms:

    1. JAVA_HOME environment variable

    2. System path

  • macOS platforms:

    1. /usr/libexec/java_home -f -v 1.8

    2. /usr/libexec/java_home -f -v 11

    3. /usr/libexec/java_home -f -v 17

• Custom Java path — Specify the folder for an installed Java version on your computer.

For version information, see Versions of OpenJDK Compatible with MATLAB by Release.

Example: jenv("system")

Example: jenv("/usr/local/jre") for OpenJDK JRE on Linux and macOS

Tips

• To use the OpenJDK JRE, you can either install the MATLAB Support for OpenJDK add-on or download a compatible OpenJDK version from https://adoptium.net.

Version History

Introduced in R2021b

R2026a: Configure JRE for MATLAB Support for OpenJDK add-on

After installing the MATLAB Support for OpenJDK add-on, call jenv with the -clear option to configure the JRE. You can configure the JRE for an individual user or for each MATLAB installation for all users. To install the add-on, see Install and Configure OpenJDK using MATLAB Add-On.

R2026a: "factory" option to be removed

When you call jenv with the Java version set to "factory", MATLAB sets the path to the Java version included with MATLAB. In a future release, MATLAB will no longer include Java by default and the version argument value "factory" will be removed.

R2023a: Return environment information

If you specify an output argument, the function returns a JavaEnvironment object, which contains information about the Java version used by MATLAB.