53

import java.applet.Applet;

import java.awt.*;

import java.net.*;

import java.io.*;

public class TextApplet extends Applet

{

  public void paint(Graphics g) 

  {

    super.paint(g);

    try {

      URL url=new 

URL(getDocumentBase(),getParameter("ArgumentURL"));

      InputStream in=url.openStream();

      ByteArrayOutputStream out=new ByteArrayOutputStream();

      byte[] b=new byte[1024]; int len;

      while((len=in.read(b,0,1024)) !=  1) {

        out.write(b,0,len);

      } 

      b=out.toByteArray();

      g.drawBytes(b,0,b.length 1,20,20);

    } 

    catch (Exception e) {

      System.out.println("Error "+e);

    }

  }

}

This is a very simple applet; the paint method opens a connection to a URL, the name of which is formed from the

document  that loaded the applet, and the value of the parameter ArgumentURL, which is passed in from a param

tag. This causes the TextApplet JSP to be called and return a computation of the date.

3.10 JavaScript: PlotScript.jsp

This example demonstrates  how to integrate a Mathematica powered web site with JavaScript. It also demonstrates

both client and server programming. The section involves some programming in JavaScript. 

Note that JavaScript and Java are different languages. JavaScript is a scripting language that is useful for manipulat 

ing documents and other features of browsers. Java is a general purpose programming language that can be used in

an HTML document via an applet. The two languages complement each other; JavaScript is useful for manipulating

the browser and documents that are open in the browser, while Java has a more sophisticated collection of functions

and can draw into the browser window. It is possible for JavaScript and Java to work together.

If  you  installed  webMathematica  as  described  

above

,  you  should  be  able  to  connect  to  this  MSP  via

http://localhost:8080/webMathematica/Examples/PlotScript.jsp. (You may have some other URL for accessing your

server.)  The  source  for  this  page  is  in  webMathematica/Examples/PlotScript.jsp  and  web 

Mathematica/Examples/PlotScript1.jsp.

First, here is the source for PlotScript.jsp.

 .