Sometimes is easier to manipulate Netscape Navigator properties
in JavaScript than directly from a Java applet. However, Java alone
does not provide you with the ability to do this. Now, with LiveConnect,
you can access JavaScript functionality from inside Java.
The following example demonstrates setting and getting a cookie
with a JavaScript function call from a Java applet.
<html>
<head>
<title>Testing</title>
<script>
function setCookie(txt){
document.cookie = txt;
alert ("String before setting cookie : " + txt);
}
function getCookie(){
var cookieAfter = document.cookie;
alert ("String after setting the cookie : " + cookieAfter);
return cookieAfter;
}
</script>
</head>
EXAMPLE
Example of using the Java call() method to call a JavaScript
function.
Enter some text and click the SetCookie button.
The JavaScript button handler will pass the text to setString()
method of the SGCookie applet. The applet creates a local copy of
the string and calls the Javascript setCookie() function to
set the text into the cookie. The applet calls the Javascript
getCookie() function to retrieve the cookie text. The SGCookie
Applet prints the the cookie text to the Java console.
<form name=myForm>
<input Type=text value="Cookie text" name=cookieTxt>
<input Type=button value="Set Cookie"
onClick="document.cookieApp.setString(document.myForm.cookieTxt.value)">
</form>
<!-- The MAYSCRIPT attribute is required in order for the Java methods
to be available to the JavaScript functions. -->
<applet code="SGCookie.class" name=cookieApp MAYSCRIPT>
</applet>
</html>
Here is the Java code for SGCookie.class. To compile this class it
may be necessary to unzip the java_30 file included with the Navigator.
Place the contents of the unzipped java library in a directory specified
on your classpath. Don't do this in your Navigator java classes
directory
or you will run into versioning problems the next time you update to
a new version of Navigator. Make sure the Netscape classes are the
first,
and only classes on the classpath at compile time.
import java.awt.*;
import java.lang.*;
import java.applet.Applet;
import netscape.javascript.JSObject;
public class SGCookie extends Applet {
JSObject win;
public void init(){
// Get a reference to the Navigator Window
try{
win = JSObject.getWindow(this);
}catch (Exception e){
// Don't throw exception information away, print it.
e.printStackTrace();
}
}
public void setString(String cookieTxt){
String msg[];
msg = new String[1];
// Create a local copy of the cookie text
msg[0] = cookieTxt;
// Call the JavaScript function to set the cookie
win.call("setCookie", msg);
// Call the other JavaScript function to get the cookie
String txt = (String)win.eval("getCookie()");
System.out.println(txt);
}
}
- Related Reading:
Any sample code included above is provided for your use on an "AS IS" basis, under the Netscape License Agreement - Terms of Use
