java种自动生成Eclipse注册码

package com;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;/** * 这是一个来自网上的一个MyEclipse的java版的注册机。 * 收藏：赵永恩 * 示例结果： *  * please input register name: admin_yong * Serial:nLR8ZC-855575-68655456975372753 *  */public class Register_Eclipse {    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 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 Register_Eclipse() {        super();    }    public static void main(String[] args) {        try {            // 输入注册名            System.out.println("please input register name:");            BufferedReader reader = new BufferedReader(new InputStreamReader(                    System.in));            String userId = null;            userId = reader.readLine();            Register_Eclipse myeclipsegen = new Register_Eclipse();            String res = myeclipsegen.getSerial(userId, "20");            // 注册号            System.out.println("Serial:" + res);            reader.readLine();        } catch (IOException ex) {        }    }}