returnValue = AppletID.appletMethod(arg1, arg2, …)
returnValue = AppletID.publicVar
AppletID.publicVar = <value>
returnValue = AppletID.publicVar.publicMethod(arg1, arg2, …)
Where AppletIDis the id attribute of the <applet> tag:<applet id="sampleApplet" code="..." />
NOTES:import java.awt.*; import javax.swing.*; public class QuickApplet extends JApplet { private JLabel label = new JLabel("This is a Java applet"); public void init() { setLayout(new FlowLayout()); label.setFont(new Font("Arial", Font.BOLD, 18)); label.setForeground(Color.RED); add(label); } public void drawText(String text) { label.setText(text); } }This applet shows only label and declare a public method drawText(String) which updates the label’s text.Here is code of the HTML page (QuickAppletTest.html):
<html> <head> <title>Javascript call Applet example</title> </head> <body> <center> <input type="button" value="Call Applet" onclick="callApplet();"/> <br/><br/> <applet id="QuickApplet" code="QuickApplet.class" width="300" height="50" > </applet> </center> </body> <script type="text/javascript"> function callApplet() { var currentTime = new Date(); var time = currentTime.toISOString(); // invoke drawText() method of the applet and pass time string // as argument: QuickApplet.drawText(time); } </script> </html>This HTML page embeds the above applet and displays a button which will invoke the applet’s method when clicked. The Javascript method callApplet() invokes the drawText() method of the applet and passes a time string as an argument. The applet, in turn, updates the label’s text by the string passed from Javascript code. Here is a screenshot of the page:
public int sum(int x, int y) { return (x + y); }
var sum = sampleApplet.sum(10, 20);
public String changeCase(String text) { return text.toUpperCase(); }
var returnText = sampleApplet.changeCase("code java");
var returnText = sampleApplet.changeCase(123456);
public boolean toggleVisible(boolean visible) { return !visible; }
var booleanReturn = sampleApplet.toggleVisible(true);
var booleanReturn = sampleApplet.toggleVisible(""); // return true var booleanReturn = sampleApplet.toggleVisible("visible"); // return false
Code in Java applet:
public int sum(int[] numbers) { int sum = 0; for (int i = 0 ; i < numbers.length; i++) { sum += numbers[i]; } return sum; }
var numbers = new Array(); numbers[0] = 10; numbers[1] = 20; numbers[2] = 30; var sum = sampleApplet.sum(numbers);
public int number;
sampleApplet.number = 10;
Code in Java applet:
public String email;
Code in Javascript:
var email = sampleApplet.email; email = email.substring(5, 18); email = "info@codejava.net"; email = email.toUpperCase();
In this example, we obtain a String object from the applet and call String’s substring(int, int) and toUpperCase() methods. The similar can be applied for other Object types.
Other Java Applet Tutorials: