How do I change the Java Virtual Machine (JVM) that MATLAB is using on Windows?
Accepted answer
MATLAB ships with one specific version of the JVM software on Windows depending on the release. MATLAB is fully supported only on these shipped versions of the JVM software. Some components might not work properly under a different version of the JVM software. For example, calling functions in a dynamically linked library that was created with a different JVM software version than that used by MATLAB might cause a segmentation violation error message.
If you choose to change the JVM software version used by MATLAB, you must:
- Download and install the desired version of the JRE (Java Runtime Environment) or the JDK (Java Development Kit). The latter contains the JRE and development tools.
- Determine the path of the JRE directory within that installation. This varies by platform and whether you downloaded the JRE or JDK (see below).
- Set the MATLAB_JAVA environment variable to this path (see below).
- Start MATLAB while that environment variable is set (see below).
Setting MATLAB to use new Java
Make sure you download the 32 or 64-bit version of the JDK or JRE, depending on your platform. To determine which platform you have, you can issue the following in MATLAB:
computer(‘arch’)
The JRE is at the parent directory of the directory that contains the file "rt.jar". For example, if "rt.jar" is at:
C:\Program Files\Java\jre6\lib\rt.jar
you should set the MATLAB_JAVA environment variable to:
C:\Program Files\Java\jre6
To set MATLAB_JAVA:
- Click Start
- Right click Computer and choose Properties
- Click Advanced System Settings and then click the Environment Variables button.
- In the system variables section, set (or add) the MATLAB_JAVA system environment variable to the JRE path determined above
This change takes effect on the next launch of MATLAB from an icon, or from a subsequently opened command prompt window.
Verifying the Installation
To verify that MATLAB is using the correct version of the JVM software, type the following at the MATLAB prompt:
version -java
If MATLAB is not using your value of MATLAB_JAVA, you may need to logout and log back in again.
