MyEclipse 6.5 序列號生成器

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextField;

public class MyEclipseGen extends JFrame implements ActionListener {

	private static final String LL = "Decompiling this copyrighted software is a violation of both your license agreement and the Digital Millenium Copyright Act of 1998 (http://www.loc.gov/copyright/legislation/dmca.pdf). Under section 1204 of the DMCA, penalties range up to a $500,000 fine or up to five years imprisonment for a first offense. Think about it; pay for a license, avoid prosecution, and feel better about yourself.";
	public JLabel title, lkey, lvlues;
	public JTextField keys, vlues;
	public JButton enter, exit;

	public String getSerial(String userId, String licenseNum) {
		java.util.Calendar cal = java.util.Calendar.getInstance();
		cal.add(1, 3);
		cal.add(6, -1);
		java.text.NumberFormat nf = new java.text.DecimalFormat("000");
		licenseNum = nf.format(Integer.valueOf(licenseNum));
		String verTime = new StringBuilder("-")
				.append(new java.text.SimpleDateFormat("yyMMdd").format(cal
						.getTime())).append("0").toString();
		String type = "YE3MP-";
		String need = new StringBuilder(userId.substring(0, 1)).append(type)
				.append("300").append(licenseNum).append(verTime).toString();
		String dx = new StringBuilder(need).append(LL).append(userId)
				.toString();
		int suf = this.decode(dx);
		String code = new StringBuilder(need).append(String.valueOf(suf))
				.toString();
		return this.change(code);
	}

	private int decode(String s) {
		int i;
		char[] ac;
		int j;
		int k;
		i = 0;
		ac = s.toCharArray();
		j = 0;
		k = ac.length;
		while (j < k) {
			i = (31 * i) + ac[j];
			j++;
		}
		return Math.abs(i);
	}

	private String change(String s) {
		byte[] abyte0;
		char[] ac;
		int i;
		int k;
		int j;
		abyte0 = s.getBytes();
		ac = new char[s.length()];
		i = 0;
		k = abyte0.length;
		while (i < k) {
			j = abyte0[i];
			if ((j >= 48) && (j <= 57)) {
				j = (((j - 48) + 5) % 10) + 48;
			} else if ((j >= 65) && (j <= 90)) {
				j = (((j - 65) + 13) % 26) + 65;
			} else if ((j >= 97) && (j <= 122)) {
				j = (((j - 97) + 13) % 26) + 97;
			}
			ac[i] = (char) j;
			i++;
		}
		return String.valueOf(ac);
	}

	public MyEclipseGen() {
		super("MyEclipseGen 6.5 註冊機");
		this.setLayout(null);

		title = new JLabel("MyEclipseGen 6.5 註冊機");// title 爲MyEclipseGen 6.5
													// 註冊機
		title.setBounds(120, 20, 150, 30);
		lkey = new JLabel("Key :");
		lkey.setBounds(30, 80, 50, 30);
		keys = new JTextField();
		keys.setBounds(80, 80, 260, 30);
		lvlues = new JLabel("Value :");
		lvlues.setBounds(30, 130, 50, 30);
		vlues = new JTextField();
		vlues.setBounds(80, 130, 260, 30);
		enter = new JButton(" 確 定 ");
		enter.addActionListener(this);
		exit = new JButton(" 退 出 ");
		exit.addActionListener(this);
		enter.setBounds(80, 180, 80, 30);
		exit.setBounds(230, 180, 80, 30);
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);// 關閉窗口
		this.setResizable(false);// 最大化
		this.setLocationRelativeTo(null);// 居中
		this.add(title);
		this.add(lkey);
		this.add(keys);
		this.add(lvlues);
		this.add(vlues);
		this.add(enter);
		this.add(exit);
		this.setSize(400, 300);
		this.setVisible(true);
	}

	public static void main(String[] args) {
		new MyEclipseGen();
	}

	@Override
	public void actionPerformed(ActionEvent e) {
		if (e.getSource() == enter) {
			if (keys.getText() == null) {
				System.out.println("0--");
				JOptionPane.showMessageDialog(null, "信息不能爲空");
			} else {
				String res = this.getSerial(keys.getText(), "5");
				vlues.setText(res);
			}
		}
		if (e.getSource() == exit) {
			int chose = JOptionPane.showConfirmDialog(null, "你真的要退出嗎", "系統警告",
					JOptionPane.ERROR_MESSAGE);// 兩個按鈕一個確定,一個取消
			if (chose == JOptionPane.YES_OPTION) {
				System.exit(1);
			}
		}
	}
}