CharGeneratorGUI

import java.awt.FlowLayout;
import java.awt.GridLayout;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import java.util.ArrayList;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public final class CharGeneratorGUI extends JFrame
{
    private final static char[] CHARS_ACCESS = {
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
        'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
        'z', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '+', '<', '>', '/', '?', '{',
        '}', '[', ']', '\\', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '-'
    };

    public CharGeneratorGUI()
    {
        super();

        super.setLayout(new FlowLayout());

        final JPanel jpTexts = new JPanel();
        jpTexts.setLayout(new GridLayout(2, 2, 10, 10)); // 2 rows, 2 columns, and gaps 10

        final JLabel jlblPhraseLength = new JLabel();
        jlblPhraseLength.setText("Length of phrase:");
        jpTexts.add(jlblPhraseLength);

        final JTextField jtfLength = new JTextField();
        jpTexts.add(jtfLength);

        final JLabel jlblGeneratedPhrase = new JLabel();
        jlblGeneratedPhrase.setText("Generated Phrase:");
        jpTexts.add(jlblGeneratedPhrase);

        final JTextField jtfPhrase = new JTextField();
        jpTexts.add(jtfPhrase);

        super.add(jpTexts);

        final JPanel jpOptions = new JPanel();
        jpOptions.setLayout(new GridLayout(2, 2, 10, 10)); // 2 rows, 2 columns, and gaps 10

        final JCheckBox jcbUpperCase = new JCheckBox();
        jcbUpperCase.setText("Upper Case");
        jpOptions.add(jcbUpperCase);

        final JCheckBox jcbLowerCase = new JCheckBox();
        jcbLowerCase.setText("Lower Case");
        jpOptions.add(jcbLowerCase);

        final JCheckBox jcbNumbers = new JCheckBox();
        jcbNumbers.setText("Numbers");
        jpOptions.add(jcbNumbers);

        final JCheckBox jcbSpecialChars = new JCheckBox();
        jcbSpecialChars.setText("Special Chars");
        jpOptions.add(jcbSpecialChars);

        super.add(jpOptions);

        final JPanel jpExtras = new JPanel();
        jpExtras.setLayout(new GridLayout(2, 1, 10, 10)); // 2 rows, 1 column, and gaps 10

        final JLabel jlblWarning = new JLabel();
        jpExtras.add(jlblWarning);

        final JButton jbtGenerate = new JButton();
        jbtGenerate.setText("Generate");
        jbtGenerate.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                jlblWarning.setText(null);
                ArrayList<Character> chars = new ArrayList<Character>();

                if (jtfLength.getText().equals("") || jtfLength.getText().equals("0")) {
                    jlblWarning.setText("Cannot generate word without length!");
                    return;
                }

                if (!(jcbUpperCase.isSelected() || jcbLowerCase.isSelected() ||
                    jcbNumbers.isSelected() || jcbSpecialChars.isSelected())) {
                    jlblWarning.setText("You must select at least one box.");
                    return;
                }

                if (jcbUpperCase.isSelected()) {
                    for (int a = 0; a <= 25; a++) {
                        chars.add(CHARS_ACCESS[a]);
                    }
                }

                if (jcbLowerCase.isSelected()) {
                    for (int b = 26; b <= 50; b++) {
                        chars.add(CHARS_ACCESS[b]);
                    }
                }

                if (jcbNumbers.isSelected()) {
                    for (int c = 51; c <= 60; c++) {
                        chars.add(CHARS_ACCESS[c]);
                    }
                }

                if (jcbSpecialChars.isSelected()) {
                    for (int d = 61; d < CHARS_ACCESS.length; d++) {
                        chars.add(CHARS_ACCESS[d]);
                    }
                }

                ArrayList<Character> lettersInWord = new ArrayList<Character>();
                String text = jtfLength.getText();
                int lengthWord = Integer.parseInt(text);

                for (int i = 0; i < lengthWord; i++) {
                    int randomNum = (int) (Math.random() * chars.size());
                    lettersInWord.add(chars.get(randomNum));
                }

                String totalWord = "";

                for (int j = 0; j < lettersInWord.size(); j++) {
                    totalWord = totalWord + lettersInWord.get(j);
                }

                jtfPhrase.setText(totalWord);
            }
        });

        jpExtras.add(jbtGenerate);

        super.add(jpExtras);

        super.setTitle("Character Generator");
        super.setSize(250, 225);
        super.setLocationRelativeTo(null);
        super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args)
    {
        new CharGeneratorGUI().setVisible(true);
    }
}