How to Applet access Javascript method

The “JSObject” object is using for Applet to access the Javascript method.

        JSObject win = JSObject.getWindow(this);
	win.call("callHello", new String[]{"mkyong"});

Tutorial

In this tutorial, you will use “JSObject” from Applet to execute a Javascript function.

1. Find the JSObject library

The “netscape.javascript.JSObject” is not in your classpath by default, you can find it inside your JRE lib folder, for example :

C:\Program Files\Java\jdk1.6.0_13\jre\lib\plugin.jar

The “plugin.jar” is what you want, get it and include it into your project classpath.

2. Create an Applet

Create an Applet and using JSObject to call a Javascript function, and pass a String variable “mkyong”.

package com.mkyong.applet;
 
import java.applet.Applet;
import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import netscape.javascript.JSObject;
 
public class JavaToJavaScript extends Applet implements ActionListener{
 
	Button button;
	private static final String EXECUTE = "EXECUTE";
 
	public void init(){
		setLayout(new FlowLayout());
	    button = new Button();
	    button.addActionListener(this);
	    button.setActionCommand(EXECUTE);
	    button.setLabel("Execute Javascript");
	    add(button);
	}
 
	@Override
	public void actionPerformed(ActionEvent e) {
		if(e.getActionCommand().equals(EXECUTE)){
			JSObject win = JSObject.getWindow(this);
			win.call("callHello", new String[]{"mkyong"});
		}
	}	    
}

3. Create a HTML – MAYSCRIPT enabled

Due to some security concerns, The JSObject is not enabled by default, you have to include the “MAYSCRIPT” inside your Applet tag to enable it.

<html>
 
<script language="Javascript">
function callHello(name)
{
	alert("hello " + name);
}
</script>
 
<head><title>Testing</title></head>
<body>
 
<h1>Applet acess Javascript method</h1>
<applet width=300 height=100 MAYSCRIPT 
code="com.mkyong.applet.JavaToJavaScript.class">
</applet>
 
</body>
</html>