Question

I need help to connect between Java and MATLAB via MatlabControl .

firstly i wanted to test code in walkthrough but every time i got same exception :

myfunc.m :

function myfunc()
    disp('hello from MYFUNC')
end

Java:

class ShowImage {

 public static void main(String[] args)
        throws MatlabConnectionException, MatlabInvocationException
    {
         // create proxy
         MatlabProxyFactoryOptions options =
            new MatlabProxyFactoryOptions.Builder()
                .setUsePreviouslyControlledSession(true)
                .build();
        MatlabProxyFactory factory = new MatlabProxyFactory(options);
        MatlabProxy proxy = factory.getProxy();

        // call builtin function
        proxy.eval("disp('hello world')");

        // call user-defined function (must be on the path)
        proxy.eval("addpath('E:\\vm')");
        proxy.feval("myfunc");
        proxy.eval("rmpath('E:\\vm)");

        // close connection
        proxy.disconnect();

}}

and here’s exceptions :

Exception in thread "main" matlabcontrol.MatlabConnectionException: Could not launch MATLAB. Command: [matlab, -r, javaaddpath 'C:\Users\walaa\Desktop\matlabcontrol-4.0.0.jar'; matlabcontrol.MatlabClassLoaderHelper.configureClassLoading(); javarmpath 'C:\Users\walaa\Desktop\matlabcontrol-4.0.0.jar'; matlabcontrol.MatlabConnector.connectFromMatlab('PROXY_RECEIVER_42dd44d9-815e-41ad-bec9-e469718b5710', 2100);]
    at matlabcontrol.RemoteMatlabProxyFactory.createProcess(RemoteMatlabProxyFactory.java:305)
    at matlabcontrol.RemoteMatlabProxyFactory.requestProxy(RemoteMatlabProxyFactory.java:116)
    at matlabcontrol.RemoteMatlabProxyFactory.getProxy(RemoteMatlabProxyFactory.java:134)
    at matlabcontrol.MatlabProxyFactory.getProxy(MatlabProxyFactory.java:81)
    at ShowImage.main(ShowImage.java:19)
Caused by: java.io.IOException: Cannot run program "matlab": CreateProcess error=2, The system cannot find the file specified
    at java.lang.ProcessBuilder.start(Unknown Source)
    at matlabcontrol.RemoteMatlabProxyFactory.createProcess(RemoteMatlabProxyFactory.java:292)
    ... 4 more
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
    at java.lang.ProcessImpl.create(Native Method)
    at java.lang.ProcessImpl.<init>(Unknown Source)
    at java.lang.ProcessImpl.start(Unknown Source)
    ... 6 more

I don’t know what’s the problem, any help will be appreciated!!

Answer 1

I assume you are using the example from here. Obviously it is tested and working, just make sure that MATLAB is on the Windows path (the error message suggests that it cannot find the program “matlab.exe”)