How do I get the absolute value of a number?

By Wayan in Core API, Math 0 Comment

The example below show you how to get the absolute value of a number. To get the absolute value or the abs value of a number we use the Math.abs() method call. The Math.abs() method is an overloaded that can accept value in type of double, float, int or long.

package org.kodejava.math;

public class GetAbsoluteValueExample {
    public static void main(String[] args) {
        Double value = -10.0D;

        double abs1 = Math.abs(value);
        System.out.println("Absolute value in double: " + abs1);

        float abs2 = Math.abs(value.floatValue());
        System.out.println("Absolute value in float : " + abs2);

        int abs3 = Math.abs(value.intValue());
        System.out.println("Absolute value in int   : " + abs3);

        long abs4 = Math.abs(value.longValue());
        System.out.println("Absolute value in long  : " + abs4);
    }
}

The code snippet above print the following result:

Absolute value in double: 10.0
Absolute value in float : 10.0
Absolute value in int   : 10
Absolute value in long  : 10

How do I place swing component using absolute coordinates?

By Wayan in Swing 0 Comment

In this example you can see how we do an absolute positioning to a swing component in the content panel. In this example we use a JPanel as the container, and we didn’t set a layout manager into it.

To position the component on the container we use the setBounds() method of the component. This method takes the x and y coordinate position and also the width and height of the component.

package org.kodejava.swing;

import javax.swing.*;

public class AbsolutePositionDemo extends JFrame {
    public AbsolutePositionDemo() {
        initializeUI();
    }

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

    private void initializeUI() {
        setSize(400, 400);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        JPanel panel = new JPanel(null);

        JTextField textField = new JTextField(20);
        textField.setBounds(50, 50, 100, 20);

        JButton button = new JButton("Button");
        button.setBounds(200, 100, 100, 20);

        JCheckBox checkBox = new JCheckBox("Check Me!");
        checkBox.setBounds(300, 250, 100, 20);

        panel.add(textField);
        panel.add(button);
        panel.add(checkBox);

        setContentPane(panel);
    }
}

How do I move to absolute or relative row?

By Wayan in JDBC 0 Comment

In this example we are showing you how to use result set absolute() and relative() method to jump from one result set row to the other. When you pass a positive number as the parameter, you’ll move from the first record to the last. But if you pass a negative number as parameter, you’ll move from the last record backward.

package org.kodejava.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MoveAbsoluteOrRelativeExample {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "kodejava";
    private static final String PASSWORD = "s3cr*t";

    public static void main(String[] args) {
        try (Connection connection =
                     DriverManager.getConnection(URL, USERNAME, PASSWORD)) {

            Statement statement = connection.createStatement(
                    ResultSet.TYPE_SCROLL_INSENSITIVE,
                    ResultSet.CONCUR_READ_ONLY);

            String sql = "SELECT id, code, name, price FROM product";
            ResultSet rs = statement.executeQuery(sql);

            // Move to the second row
            rs.absolute(2);
            System.out.println("You are now in: " + rs.getRow());

            // Move 2 records forward from the current position 
            // (fourth row)
            rs.relative(2);
            System.out.println("You are now in: " + rs.getRow());

            // Move to the last row in the result set
            rs.absolute(-1);
            System.out.println("You are now in: " + rs.getRow());

            // Move 3 records backward from the current position 
            // (second row)
            rs.relative(-3);
            System.out.println("You are now in: " + rs.getRow());
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The code output the following result:

You are now in: 2
You are now in: 4
You are now in: 5
You are now in: 2

Maven Dependencies

<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.1.0</version>
</dependency>

Maven Central