Matlab, PHP & Java

Question

I am trying to create a web app which uses a Matlab function using a PHP/Java Bridge. Let me explain:

1. I need to write the function in matlab
2. convert the function into a jar file using the matlab ja builder
3. Use a PHP/Java Bridge to call this function in php and display results.

So far I have done this. I created a very simple Matlab file named "makesqr.m" which is as below:

 function y=makesqr(x)
   y = magic(x);
 end

I packaged this into a jar file named "themagic.jar" using Matlab builder JA. Installed Tomcat and PHP/Java Bridge and wrote a php function which calls the makesqr func like this:

<?php
  require_once("http://localhost:8080/JavaBridgeTemplate621/java/Java.inc");
  $myclass=new Java("themagic.mksqr");//mksqr is the class which has the method named makesqr
  $input = new Java("java.lang.Double", 5);
  $noofoutputs=new Java("java.lang.Integer",1);
  $matinp=new Java("com.mathworks.toolbox.javabuilder.MWNumericArray",$input);
  $myclass->makesqr($noofoutputs,$matinp);
 ?>

I just keep getting this error:

Uncaught [[o:Exception]:"java.lang.Exception: Invoke failed: [[o:mksqr]]->makesqr((o:int)[o:Integer], (o:Object;)[o:MWNumericArray]). Cause: java.lang.IllegalArgumentException: argument type mismatch VM: 1.6.0_25@http://java.sun.com/" at: #-9 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) #-8 sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) #-7 sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) #-6 java.lang.reflect.Method.invoke(Unknown Source) #-5 php.java.bridge.JavaBridge.Invoke(JavaBridge.java:1044) #-4 php.java.bridge.Request.handleRequest(Request.java:417) #-3 php.java.bridge.Request.handleRequests(Request.java:500) #-2 php.java.bridge.http.ContextRunner.run(ContextRunner.java:145) #-1 php.java.bridge.ThreadPool$Delegate.run(ThreadPool.java:60) #0 http://localhost:8080/JavaBridgeTemplate621/java/Java.inc(232): java_ThrowExceptionProxyFactory->getProxy(7, 'com.mathworks.t...', 'T', true) #1 http://localhost:8080/JavaBridgeTemplate621/java/Java.inc(360): java_Arg->get in http://localhost:8080/JavaBridgeTemplate621/java/Java.inc on line 195

I dont understand what is to be done here.

Edit:-@renick- Hi I used the caucho quercus and wrote the php file"testjava.php" as below:-

$myclass=new Java("themagic.theMagic");
$input = new Java("java.lang.Double", 5);
$output=new Java("java.lang.Integer",1);
$result=new Java("java.lang.Object");
$n=new Java("com.mathworks.toolbox.javabuilder.MWNumericArray",$input,MWClassID.DOUBLE);
$result=$myclass->makesqr($output,$n);

Now when I call this file as "localhost:8080/testjava.php". I get the below error:

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

com.caucho.quercus.QuercusException: themagic.theMagic.makesqr: null
    com.caucho.quercus.env.JavaMethod.invoke(JavaMethod.java:131)
    com.caucho.quercus.env.JavaInvoker.callMethod(JavaInvoker.java:737)
    com.caucho.quercus.env.JavaOverloadMethod.callMethod(JavaOverloadMethod.java:179)
    com.caucho.quercus.program.JavaClassDef.callMethod(JavaClassDef.java:658)
    com.caucho.quercus.env.JavaValue.callMethod(JavaValue.java:327)
    com.caucho.quercus.expr.AbstractMethodExpr.eval(AbstractMethodExpr.java:97)
    com.caucho.quercus.expr.ObjectMethodExpr.eval(ObjectMethodExpr.java:97)
    com.caucho.quercus.expr.AbstractMethodExpr.evalCopy(AbstractMethodExpr.java:63)
    com.caucho.quercus.expr.BinaryAssignExpr.eval(BinaryAssignExpr.java:88)
    com.caucho.quercus.expr.Expr.evalTop(Expr.java:523)
    com.caucho.quercus.statement.ExprStatement.execute(ExprStatement.java:67)
    com.caucho.quercus.statement.BlockStatement.execute(BlockStatement.java:105)
    com.caucho.quercus.program.QuercusProgram.execute(QuercusProgram.java:413)
    com.caucho.quercus.page.InterpretedPage.execute(InterpretedPage.java:89)
    com.caucho.quercus.env.Env.executePageTop(Env.java:3951)
    com.caucho.quercus.env.Env.executeTop(Env.java:3892)
    com.caucho.quercus.servlet.QuercusServletImpl.service(QuercusServletImpl.java:188)
    com.caucho.quercus.servlet.QuercusServlet.service(QuercusServlet.java:594)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause

java.lang.NullPointerException
    com.mathworks.toolbox.javabuilder.internal.MWMCR.invoke(MWMCR.java:492)
    themagic.theMagic.makesqr(theMagic.java:158)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    com.caucho.quercus.env.JavaMethod.invoke(JavaMethod.java:117)
    com.caucho.quercus.env.JavaInvoker.callMethod(JavaInvoker.java:737)
    com.caucho.quercus.env.JavaOverloadMethod.callMethod(JavaOverloadMethod.java:179)
    com.caucho.quercus.program.JavaClassDef.callMethod(JavaClassDef.java:658)
    com.caucho.quercus.env.JavaValue.callMethod(JavaValue.java:327)
    com.caucho.quercus.expr.AbstractMethodExpr.eval(AbstractMethodExpr.java:97)
    com.caucho.quercus.expr.ObjectMethodExpr.eval(ObjectMethodExpr.java:97)
    com.caucho.quercus.expr.AbstractMethodExpr.evalCopy(AbstractMethodExpr.java:63)
    com.caucho.quercus.expr.BinaryAssignExpr.eval(BinaryAssignExpr.java:88)
    com.caucho.quercus.expr.Expr.evalTop(Expr.java:523)
    com.caucho.quercus.statement.ExprStatement.execute(ExprStatement.java:67)
    com.caucho.quercus.statement.BlockStatement.execute(BlockStatement.java:105)
    com.caucho.quercus.program.QuercusProgram.execute(QuercusProgram.java:413)
    com.caucho.quercus.page.InterpretedPage.execute(InterpretedPage.java:89)
    com.caucho.quercus.env.Env.executePageTop(Env.java:3951)
    com.caucho.quercus.env.Env.executeTop(Env.java:3892)
    com.caucho.quercus.servlet.QuercusServletImpl.service(QuercusServletImpl.java:188)
    com.caucho.quercus.servlet.QuercusServlet.service(QuercusServlet.java:594)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.32 logs.

Apache Tomcat/6.0.32

Would anyone have any idea as to what I am doing wrong?

Note: I dont know a word of Java but am stuck in a situation where I have to handle this

Answer 1

Since you already have a jar and tomcat installed. You can maybe just wrap it into a web-service. Write a small servlet mapped to this class and you can curl from php and get a json formatted output. (you can take the Matlab method's output in your wrapper code, convert to json and send the answer back).

This will free you of all type conversions, both while sending and receiving data. Look into RestEasy for an even easier way of sending arguments. Although for simple applications, request.getparameter() with a cast to desired type works great.