Generate a Java Package and Build a Java Application

Supported platform: Windows^®, Linux^®, Mac

This example shows how to use the Library Compiler app to create a Java^® package for a MATLAB^® function. You can then pass the generated package to the developer who is responsible for integrating it into an application. This example also shows how to call the Java package from a Java application. The target system does not require a licensed copy of MATLAB.

Create Function in MATLAB

In MATLAB, examine the MATLAB code that you want packaged. For this example, open makesqr.m located in matlabroot\toolbox\javabuilder\Examples\MagicSquareExample\MagicDemoComp.

makesqr.m

At the MATLAB command prompt, enter makesqr(5).

The output is:

    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9

Create Java Application Using Library Compiler App

On the MATLAB Apps tab, on the far right of the Apps section, click the arrow. In Application Deployment, click Library Compiler.
Alternatively, you can open the Library Compiler app from the MATLAB command prompt by entering:
```
libraryCompiler
```
In the Type section of the toolstrip, click Java Package.
In the Library Compiler app project window, specify the files of the MATLAB application that you want to deploy.
1. In the Exported Functions section of the toolstrip, click .
2. In the Add Files window, browse to the example folder, and select the function you want to package. Click Open.
The function is added to the list of exported function files. Repeat this step to package multiple files in the same application.
For this example, navigate to matlabroot\toolbox\javabuilder\Examples\MagicSquareExample\MagicDemoComp and select makesqr.m.
In the Packaging Options section of the toolstrip, decide whether to include the MATLAB Runtime installer in the generated application by selecting one of the options:
- Runtime downloaded from web — Generate an installer that downloads the MATLAB Runtime and installs it along with the deployed MATLAB application. You can specify the filename of the installer.
- Runtime included in package — Generate an application that includes the MATLAB Runtime installer. You can specify the filename of the installer.
  Note
  The first time you select this option, you are prompted to download the MATLAB Runtime installer.

Specify Package Settings

The Library Name field is automatically populated with makesqr as the name of the package. The same name is followed through in the implementation of the package.
Verify that the function defined in makesqr.m is mapped into Class1.
Add MATLAB files to generate the sample Java driver files. Although Java driver files are not necessary to create packages, they are used to demonstrate how to Install and Implement MATLAB Generated Java Application.
In the Samples section, select Create New Sample, and click makesqr.m. A MATLAB file opens for you to edit. Define the input variables as necessary for your application, save the file, and return to the Library Compiler app. For more information and limitations, see Sample Driver File Creation.

Customize the Application and Its Appearance

You can customize the installer, customize your application, and add more information about the application as follows:

Library information — Information about the deployed application. You can also customize the appearance of the application by changing the application icon and splash screen. The generated installer uses this information to populate the installed application metadata. See Customize the Installer.
Additional installer options — Default installation path for the generated installer and custom logo selection. See Change the Installation Path.
Files required for your library to run — Additional files required by the generated application to run. These files are included in the generated application installer. See Manage Required Files in Compiler Project.
Files installed for your end user — Files that are installed with your application. These files include:
- Generated readme.txt
- Generated executable for the target platform
See Specify Files to Install with Application

Package the Application

To generate the packaged application, click Package.
In the Save Project dialog box, specify the location to save the project.
In the Package dialog box, verify that Open output folder when process completes is selected.
When the packaging process is complete, examine the generated output.
- Three folders are generated in the target folder location: for_redistribution, for_redistribution_files_only, and for_testing.
  For more information about the files generated in these folders, see Files Generated After Packaging MATLAB Functions.
- PackagingLog.txt — Log file generated by MATLAB Compiler™.

Install and Implement MATLAB Generated Java Application

After creating your Java packages, you can call them from a Java application. The Java application that you create uses the sample Java driver code generated during packaging. The Java driver code calls the Java packages, and it is based on the sample MATLAB file you selected in previous setup steps.

These steps are also explained in the GettingStarted.html file in for_redistribution_files_only folder. Before starting, make sure that you Install and Configure the MATLAB Runtime, and that you have the Java Development Kit installed.

Copy and paste the generated Java driver code file from the for_redistribution_files_only\samples folder into the for_redistribution_files_only folder created when you created the package.
Use the system command line to navigate to the for_redistribution_files_only folder, where you copied the generated sample Java driver code file.
Compile the application using javac at the system command prompt.
```
javac -classpath "mcrroot\toolbox\javabuilder\jar\platform\javabuilder.jar";.\makesqr.jar .\getmagic.java
```
Note
On UNIX^® platforms, use colon (:) as the class path delimiter instead of semicolon (;).
mcrroot is the path to the MATLAB Runtime installation on your system. If you have MATLAB installed on your system instead, you can use the path to your MATLAB installation.
From the system command prompt, run the application. If you used sample MATLAB code in the packaging steps, this application should return the same output as the MATLAB code.
```
java -classpath .;"mcrroot\toolbox\javabuilder\jar\platform\javabuilder.jar";.\makesqr.jar makesqrSample1
```
```
    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9
```
Place a dot (.) in the first position of the class path. If it is not there, you get a message stating that Java cannot load the class.
Note
On UNIX platforms, use colon (:) as the class path delimiter instead of semicolon (;).

Documentation