How do I perform HTTP GET method?

By I Wayan Saryada in Apache Commons, Commons HttpClient 0 Comment

Below is an example using Commons HttpClient library to retrieve information from a website using HTTP GET method. The response will be returned as stream by the HttpMethod.getResponseBodyAsStream() method. If you want something simple you can get the response as string by using the HttpMethod.getResponseBodyAsString() method.

package org.kodejava.commons.httpclient;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;

import java.io.*;
import java.nio.charset.StandardCharsets;

public class HttpGetDemo {
    public static void main(String[] args) {
        HttpClient client = new HttpClient();
        HttpMethod method = new GetMethod("https://kodejava.org");

        try {
            client.executeMethod(method);

            if (method.getStatusCode() == HttpStatus.SC_OK) {
                InputStream is = method.getResponseBodyAsStream();

                if (is != null) {
                    Writer writer = new StringWriter();
                    char[] buffer = new char[1024];
                    try {
                        Reader reader = new BufferedReader(new InputStreamReader(is,
                                StandardCharsets.UTF_8));
                        int length;
                        while ((length = reader.read(buffer)) != -1) {
                            writer.write(buffer, 0, length);
                        }
                    } finally {
                        is.close();
                    }
                    System.out.println("Response = " + writer);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            method.releaseConnection();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>

Maven Central

How do I format date using a locale based format?

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

The code below demonstrate how to format date information for a specific locale. In the example utilize the java.text.SimpleDateFormat class.

package org.kodejava.text;

import java.util.Locale;
import java.util.Date;
import java.text.SimpleDateFormat;

public class FormatDateLocale {
    public static void main(String[] args) {
        // Defines an array of Locale we are going to use for
        // formatting date information.
        Locale[] locales = new Locale[] {
            Locale.JAPAN,
            Locale.CHINA,
            Locale.KOREA,
            Locale.TAIWAN,
            Locale.ITALY,
            Locale.FRANCE,
            Locale.GERMAN
        };

        // Get an instance of current date time
        Date today = new Date();

        // Iterates the entire Locale defined above and create a long
        // formatted date using the SimpleDateFormat.getDateInstance()
        // with the format, the Locale and the date information.
        for (Locale locale : locales) {
            System.out.printf("Date format in %s = %s%n",
                locale.getDisplayName(), SimpleDateFormat.getDateInstance(
                    SimpleDateFormat.LONG, locale).format(today));
        }
    }
}

The result of our code are:

Date format in Japanese (Japan) = 2021年10月6日
Date format in Chinese (China) = 2021年10月6日
Date format in Korean (South Korea) = 2021년 10월 6일
Date format in Chinese (Taiwan) = 2021年10月6日
Date format in Italian (Italy) = 6 ottobre 2021
Date format in French (France) = 6 octobre 2021
Date format in German = 6. Oktober 2021

How do I customize JButton icons?

By I Wayan Saryada in Swing 0 Comment

The example below shows you how we can customize the icon for JButton Swing components.

package org.kodejava.swing;

import javax.swing.*;
import java.awt.*;

public class JButtonCustomIcon extends JFrame {
    public JButtonCustomIcon() throws HeadlessException {
        initialize();
    }

    private void initialize() {
        setSize(500, 500);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setLayout(new FlowLayout(FlowLayout.LEFT));

        JButton button = new JButton("Press Me!");

        // Below is how we can set various icons for the JButton swing
        // component. There are the default icon, selected, disabled, pressed
        // and rollover icons.
        button.setIcon(new ImageIcon("default.png"));
        button.setSelectedIcon(new ImageIcon("selected.png"));
        button.setDisabledIcon(new ImageIcon("disabled.png"));
        button.setDisabledSelectedIcon(new ImageIcon("disabledSelected.png"));
        button.setPressedIcon(new ImageIcon("pressed.png"));
        button.setRolloverIcon(new ImageIcon("rollover.png"));
        button.setRolloverSelectedIcon(new ImageIcon("rolloverSelected.png"));

        getContentPane().add(button);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new JButtonCustomIcon().setVisible(true));
    }
}

How do I customize JCheckBox icons?

By I Wayan Saryada in Swing 0 Comment

JCheckBox can have a different icon for its states, there are default icon, a selected icon, disabled icon, pressed icon or rollover icon, etc. See the code below and have a try on it.

package org.kodejava.swing;

import javax.swing.*;
import java.awt.*;

public class JCheckBoxCustomIcon extends JFrame {
    public JCheckBoxCustomIcon() throws HeadlessException {
        initialize();
    }

    private void initialize() {
        setSize(500, 500);
        setTitle("JCheckBox Icon Demo");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setLayout(new FlowLayout(FlowLayout.LEFT));

        // Creating checkbox with text label
        JCheckBox checkBox = new JCheckBox("Check me!");
        checkBox.setSelected(true);

        // Set default icon for checkbox
        checkBox.setIcon(new ImageIcon("icon.png"));
        // Set selected icon when checkbox state is selected
        checkBox.setSelectedIcon(new ImageIcon("selectedIcon.png"));
        // Set disabled icon for checkbox
        checkBox.setDisabledIcon(new ImageIcon("disabledIcon.png"));
        // Set disabled-selected icon for checkbox
        checkBox.setDisabledSelectedIcon(new ImageIcon("disabledSelectedIcon.png"));
        // Set checkbox icon when checkbox is pressed
        checkBox.setPressedIcon(new ImageIcon("pressedIcon.png"));
        // Set icon when a mouse is over the checkbox
        checkBox.setRolloverIcon(new ImageIcon("rolloverIcon.png"));
        // Set icon when a mouse is over a selected checkbox
        checkBox.setRolloverSelectedIcon(new ImageIcon("rolloverSelectedIcon.png"));

        getContentPane().add(checkBox);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new JCheckBoxCustomIcon().setVisible(true));
    }
}

How do I get or set the state of JCheckBox?

By I Wayan Saryada in Swing 0 Comment

This simple example shows you how to get or set the state of a JCheckBox. The method to set the state is JCheckBox.setSelected(boolean) and the method for getting the state is JCheckBox.isSelected() which return a boolean value.

package org.kodejava.swing;

import javax.swing.*;
import java.awt.*;

public class CheckBoxState extends JFrame {
    public CheckBoxState() throws HeadlessException {
        initialize();
    }

    private void initialize() {
        setSize(500, 500);
        setTitle("JCheckBox Demo");
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setLayout(new FlowLayout(FlowLayout.LEFT));

        // Creating checkbox with text label
        JCheckBox checkBox = new JCheckBox("Check me!");
        checkBox.setSelected(true);

        // Get checkbox selection state
        boolean selected = checkBox.isSelected();
        if (selected) {
            System.out.println("Check box state is selected.");
        } else {
            System.out.println("Check box state is not selected.");
        }

        getContentPane().add(checkBox);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> new CheckBoxState().setVisible(true));
    }
}