Documentation

Configure Your Java Environment

Before you can use the generated Java® packages in a Java development environment, you need to ensure that your Java environment is properly configured. You must verify that:

  • Your system uses a version of the Java Developer’s Kit (JDK™) that is compatible with MATLAB®.

  • JAVA_HOME is set to the folder containing the system’s JDK installation.

  • CLASSPATH contains all of the MATLAB library JAR files and the JAR files for the packages containing your compiled MATLAB code.

  • The MATLAB native library paths are properly configured.

Note

For updated Java system requirements, including versions of Java Developer's Kit (JDK) and Java Runtime Environment (JRE™), see the supported compiler page at https://www.mathworks.com/support/compilers/current_release/.

Install the Required JDK

To install the proper version of the JDK:

  1. Verify the version of Java your MATLAB installation is using by running the following MATLAB command:

    version -java
  2. Download a Java Developer's Kit (JDK) with the same major version from https://adoptopenjdk.net/.

  3. Install the JDK.

Note

If you are not developing applications or compiling MATLAB code, you can use the Java Runtime Environment (JRE) instead of the JDK.

Set JAVA_HOME

  1. From the system command prompt, set the system environment variable, JAVA_HOME, to point to your JDK installation.

    For example on Windows® enter set JAVA_HOME=path_to_Java_install.

  2. If you are compiling MATLAB code, verify that MATLAB is reading the correct value of JAVA_HOME.

    At the MATLAB command prompt, type getenv JAVA_HOME to display the value of JAVA_HOME in use by MATLAB.

  3. Verify that the folder containing your Java installation has been added to your system PATH environment variable.

    For example on Windows enter set PATH=%PATH%;path_to_Java_install.

Set the CLASSPATH

To build and run a Java application that uses a MATLAB Compiler SDK™ generated component, the system must locate:

  • JAR files containing the MATLAB libraries

  • Packages that you have developed and built

Java classes compiled with MATLAB Compiler SDK use classes contained in the com.mathworks.toolbox.javabuilder package. To use the compiled classes, you need to include a file called javabuilder.jar on the Java class path. You can find this file in one of the following folders:

MATLAB installed on your systemmatlabroot/toolbox/javabuilder/jar
MATLAB Runtime installed on your systemmcrroot/toolbox/javabuilder/jar

Note

matlabroot refers to the root folder into which the MATLAB installer has placed the MATLAB files. mcrroot refers to the root folder under which MATLAB Runtime is installed.

In addition, you need to add to the JAR files created by the compiler to the class path.

Configure the Native Library Path Variables

The operating system uses the native library path to locate native libraries that are needed to run your Java class. See the following list of variable names according to operating system:

Windows PATH
Linux®LD_LIBRARY_PATH
MacintoshDYLD_LIBRARY_PATH

The native MATLAB or MATLAB Runtime files needed to execute the compiled MATLAB functions called from the Java code must be included on the paths listed by your system’s native library path variable.