How do I read an applet parameters?

By I Wayan Saryada in Applet, Core API 0 Comment 
package org.kodejava.applet;

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;

public class AppletParameterExample extends Applet {
    private String name = "";

    public void init() {
        // Here we read a parameter named name from the applet tag definition
        // in our html file.
        name = getParameter("name");
    }

    public void paint(Graphics g) {
        g.setColor(Color.BLUE);
        g.drawString("Hello " + name + ", Welcome to the Applet World.", 0, 0);
    }
}

Now we have the applet code ready. To enable the web browser to execute the applet create the following html page.

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Parameterized Applet</title>
</head>
<body>
<applet code="org.kodejava.applet.AppletParameterExample"
        height="150" width="350">
    <param name="name" value="Mr. Bean"/>
</applet>
</body>
</html>
** Deprecated: The Applet API is deprecated since JDK 9, no replacement.

How do I convert string date to long value?

By I Wayan Saryada in Core API, Util Package 0 Comment 
package org.kodejava.util;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class StringDateToLong {
    public static void main(String[] args) {
        // Here we have a string date, and we want to covert it to long value
        String today = "25/09/2021";

        // Create a SimpleDateFormat which will be used to convert the string to
        // a date object.
        DateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
        try {
            // The SimpleDateFormat parse the string and return a date object.
            // To get the date in long value just call the getTime method of
            // the Date object.
            Date date = formatter.parse(today);
            long dateInLong = date.getTime();

            System.out.println("Date         = " + date);
            System.out.println("Date in Long = " + dateInLong);
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }
}

The result of the code snippet:

Date         = Sat Sep 25 00:00:00 CST 2021
Date in Long = 1632499200000

How do I calculate process elapsed time?

By I Wayan Saryada in Core API, Lang Package 0 Comment

This example shows us how to use the System.nanoTime() method to get the amount of time a process take place. Please be aware that the nano time value is not related to the real world time value.

package org.kodejava.lang;

public class ElapsedTimeExample {
    public static void main(String[] args) {
        // Get the start time of the process
        long start = System.nanoTime();
        System.out.println("Start: " + start);

        // Just do some a bit long process calculating the total value
        // of even number from zero to 10000
        int totalEven = 0;
        for (int i = 0; i < 10000; i++) {
            if (i % 2 == 0) {
                totalEven = totalEven + i;
            }
        }

        // Get the end time of the process
        long end = System.nanoTime();
        System.out.println("End  : " + end);

        long elapsedTime = end - start;

        // Show how long it took to finish the process
        System.out.println("The process took approximately: "
            + elapsedTime + " nano seconds");
    }
}

And example of the result are:

Start: 35034476484699
End  : 35034477434200
The process took approximately: 949501 nano seconds

How do I create a Hello World Applet?

By I Wayan Saryada in Applet, Core API 0 Comment

The code below demonstrate the very basic of Java applet. Applet is a small Java application that can be embedded on the web browser.

package org.kodejava.applet;

import java.applet.*;
import java.awt.*;

public class HelloWorldApplet extends Applet {
    public void init() {
    }

    public void start() {
    }

    public void stop() {
    }

    public void destroy() {
    }

    public void paint(Graphics g) {
        g.setColor(Color.GREEN);
        g.drawString("Hello World", 50, 100);
    }
}

To display the applet we need to create an HTML document. Here is a simple example of the document.

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Hello World Applet</title>
</head>

<body>
<applet
        code="org.kodejava.applet.HelloWorldApplet"
        height="250"
        width="250">
</applet>
</body>
</html>

You can now load the applet in your browser or by using the appletviewer utility.

appletviewer.exe hello-world-applet.html
** Deprecated: The Applet API is deprecated since JDK 9, no replacement.

How do I get the available font family names?

By I Wayan Saryada in AWT, Core API 0 Comment 
package org.kodejava.awt;

import java.awt.GraphicsEnvironment;

public class FontFamilyNameList {
    public static void main(String[] args) {
        // Get all available font family names from GraphicsEnvironment
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        String[] familyNames = ge.getAvailableFontFamilyNames();

        // Iterates familyNames array to display the available font's family names
        for (String familyName : familyNames) {
            System.out.println("Family name: " + familyName);
        }
    }
}

Some font family names are shown below:

Family name: Agency FB
Family name: Algerian
Family name: Arial
Family name: Arial Black
Family name: Arial Narrow
Family name: Arial Rounded MT Bold
Family name: Bahnschrift
Family name: Baskerville Old Face
Family name: Bauhaus 93
Family name: Bell MT
...