How can I suppress MATLAB command window when calling it from Java?

When you say "calling it from Java", are you bypassing the Matlab command for batch computing, or do you want to insert a long running Matlab session into your process and call M code from Java code multiple times? What OS do you want to run?

Matlab has several deployment tools that allow you to embed a Matlab interpreter and a set of Matlab sources inside a host language such as C / C ++ or Java. This is that the "Matlab compiler" is not a real compiler, but a tool that packages the Matlab runtime along with the .m source code in a package that looks like a DLL or an application. "Standalone Matlab Application" is Matlab code that has been packaged this way along with a thin C wrapper that calls the application entry point into your M code.

Matlab Java Builder is the same thing that bundles this expanded Matlab engine inside a Java class. If you want to get a license for this, it can make it easier and cosmetically to clean up the embedded Matlab inside your Java application. This is probably what you want.

These deployed Matlab applications do not have command windows as they are meant to be shared with your application. They live in the same process. And last but not least, they do not require licensing fees to run a deployed application. Deploying regular Matlab requires all users to run it to obtain a license for Matlab and every toolkit used.

If you remove the shell, the command line "matlab -nosplash -nodesktop" will suppress the GUI on Unix. But on Windows, you still get a minimal Matlab command window. The "-automation" switch on Windows will at least minimize it. I don't know how to completely suppress it at startup.

However, once Matlab is up and running, you can take advantage of the fact that the Matlab GUI itself is implemented in Java and hide it. Get your Matlab session to run this hidematlab () with the command line "-r" or startup.m. Note that this is a hack using undocumented internals of Matlab and is clearly not supported by MathWorks.

function hidematlab()
%HIDEMATLAB Hide the main Matlab desktop window (HACK)

dtWin = desktopwindow();
if ~isempty(dtWin)
    dtWin.setVisible(0);
end

function out = desktopwindow()
%DESKTOPWINDOW Find the main Matlab desktop window (HACK)

wins = java.awt.Window.getOwnerlessWindows();
out = [];
for i = 1:numel(wins)
    if isa(wins(i), 'com.mathworks.mde.desk.MLMainFrame')
        out = wins(i);
        return;
    end
end

      

        
        
        
      

    

Beware of gotchas when bombarded on Windows where Matlab is inherently a graphical application. If your M code throws errors that appear at the top level or a segfault, you may find that your Matlab session was hanging waiting for non-existent user input, instead of returning you an error.