Mathematica and Java Calling Java from Mathematica

tarix	26.06.2016
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Mathematica and Java

Calling Java from Mathematica

<< JLink`
InstallJava[];

myWindow = JavaNew["com.wolfram.jlink.MathJFrame"];

myWindow@setSize[200, 200];
myWindow@setLocation[300, 300];
JavaShow[myWindow];

Constructors["java.awt.Button"]

Fields["java.awt.Button"]
Methods["java.awt.Button", Inherited → False]
Methods["java.awt.Button", Inherited → False]
Methods["java.awt.Button", "set*"]

Java  Mathematica Reference

	Java	Mathematica
Constructors	MyClass obj = new MyClass( args );	obj = JavaNew["MyClass", args]

Methods	obj.methodName( args );	obj@methodName[args];

Fields	obj.fieldName = 1;	obj@fieldName =1
	var1 = obj.fieldName;	var1 = obj@fieldName

Static Methods	MyClass.statMethod(args);	MyClass`statMethod[args];

Static Fields	MyClass.statField = 1	MyClass`statField = 1
	var1 = MyClass.statField	var1 = MyClass`statField

Import Class	import java.lang.Math	LoadJavaClass["java.lang.Math"]

Release Object		ReleaseJavaObj[obj]

Block	{ ... }	JavaBlock[ ... ]

Getting Information About Classes

Constructors["java.awt.Button"]

Lists all constructors of the Button class.

Fields["java.awt.Button"]

Lists all fields of the Button class.

Methods["java.awt.Button", Inherited → False]

Lists all methods of the Button class excluding those inherited from super classes.

Methods["java.awt.Button", "set*"]

Lists all methods of the Button class that begin with “set”.

Calling Mathematica from Java

Setup the KernelLink

String[] argv1 = {

"-linkmode", "launch", "-linkname",

"c:\\program files\\wolfram research\\mathematica\\5.2\\mathkernel.exe" };
KernelLink ml = MathLinkFactory.createKernelLink(argv1);

Evaluate Expression

ml.evaluate("2+2");

ml.waitForAnswer();

int result = ml.getInteger();

System.out.println("2 + 2 = " + result);

Get Image Data

ml.discardAnswer();

Image img = ml.evaluateToImage(

"Plot[Sin[x], {x, 0, 2Pi}]",

450, 450);

Sample Code

KernelLink ml = null;

String[] argv1 = { "-linkmode", "launch", "-linkname",

"c:\\program files\\wolfram research\\mathematica\\5.2\\mathkernel.exe" };
// Create a KernelLink

try {

ml = MathLinkFactory.createKernelLink(argv1);

}

catch (MathLinkException e) {

System.out.println("Fatal error opening link: " + e.getMessage());

return;

}
try {

// Get rid of the initial InputNamePacket the kernel

// will send when it is launched.

ml.discardAnswer();

ml.evaluate("<ml.discardAnswer();

ml.evaluate("2+2");

ml.waitForAnswer();

int result = ml.getInteger();

System.out.println("2 + 2 = " + result);

// Here's how to send the same input, but not as a string:

ml.putFunction("EvaluatePacket", 1);

ml.putFunction("Plus", 2);

ml.put(3);

ml.endPacket();

ml.waitForAnswer();

result = ml.getInteger();

System.out.println("3 + 3 = " + result);

// If you want the result back as a string, use evaluateToInputForm

// or evaluateToOutputForm. The second arg for either is the

// requested page width for formatting the string. Pass 0 for

// PageWidth->Infinity. These methods get the result in one

// step--no need to call waitForAnswer.

String strResult = ml.evaluateToOutputForm("4+4", 0);

System.out.println("4 + 4 = " + strResult);

strResult = ml.evaluateToOutputForm(" Integrate[Cos[x], x]", 0);

System.out.println("Integrate[Cos[x], x] = " + strResult);
}

catch (MathLinkException e)

{

System.out.println("MathLinkException occurred: " + e.getMessage());

}

finally

{

// Close the KernelLink

ml.close();

}

Output from Sample Code

2 + 2 = 4

3 + 3 = 6

4 + 4 = 8

4 + 4 = Sin[x]

Mathematica and Java Calling Java from Mathematica