A simple ram selector in Java

RamSelector.java

package fr.mrmicky.ramselector;

import javax.swing.*;
import java.lang.management.ManagementFactory;

/**
 * @author MrMicky
 */
@SuppressWarnings("serial")
public class RamSelector extends JFrame {

	private static final boolean COMPATIBLE = System.getProperty("sun.arch.data.model").equals("64");
	private JComboBox<String> ramBox = new JComboBox<>();
	private long maxRam = 8;

	@SuppressWarnings("restriction")
	public RamSelector(String defaultRam) {
		int ram = 1;
		if (defaultRam != null) {
			try {
				ram = Integer.parseInt(defaultRam) - 1;
				if (ram < 0) {
					ram = 0;
				}
			} catch (NumberFormatException ignored) {
			}
		}

		try {
			maxRam = ((com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean())
					.getTotalPhysicalMemorySize() / 1024 / 1024 / 1024;
			if (maxRam < 1) {
				maxRam = 1;
			}
		} catch (Throwable ignored) {
		}

		getContentPane().setLayout(null);
		setTitle("Settings");
		setResizable(false);
		setSize(250, 175);
		setDefaultCloseOperation(WindowConstants.HIDE_ON_CLOSE);

		JLabel ramLabel = new JLabel("RAM: ", SwingConstants.CENTER);
		ramLabel.setBounds(10, 67, 56, 25);
		getContentPane().add(ramLabel);

		// Replace with your version
		JLabel versionLabel = new JLabel("Version: " + "1.0");
		versionLabel.setBounds(10, 11, 224, 14);
		getContentPane().add(versionLabel);

		// Add your name
		JLabel authorLabel = new JLabel("Author: ");
		authorLabel.setBounds(10, 36, 224, 20);
		getContentPane().add(authorLabel);

		ramBox.setBounds(76, 67, 158, 25);
		getContentPane().add(ramBox);

		JButton okBtn = new JButton("OK");
		okBtn.setBounds(10, 102, 224, 25);
		okBtn.addActionListener(e -> setVisible(false));
		getContentPane().add(okBtn);

		for (int i = 1; i <= maxRam; i++) {
			ramBox.addItem(" " + i + " Go");
		}
		ramBox.setSelectedIndex(ram < maxRam ? ram : 0);
	}

	public void display() {
		if (!COMPATIBLE) {
			JOptionPane.showMessageDialog(this,	"You have a 32bits Java, you can't have more than 1024mo of ram",
					"Java 32bits", JOptionPane.WARNING_MESSAGE);
			return;
		}

		setLocationRelativeTo(null);
		setVisible(true);
	}

	public int getRam() {
		return COMPATIBLE ? ramBox.getSelectedIndex() + 1 : 1;
	}

	public void setRam(int index) {
		ramBox.setSelectedIndex(index - 1);
	}

	public long getMaxRam() {
		return maxRam;
	}

	public String[] getRamArguments() {
		int ram = getRam() * 1024;

		return new String[] { "-Xms" + (ram - 512) + "M", "-Xmx" + ram + "M" };
	}
}