class="java">import java.security.MessageDigest; /** * 对密码进行加密和验证的类 */ public class CipherUtil{ //十六进制下数字到字符的映射数组 private final static String[] hexDigits = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"}; /** * 把inputString加密 */ public static String generatePassword(String inputString){ return encodeByMD5(inputString); } /** * 验证输入的密码是否正确 * @param password 加密后的密码 * @param inputString 输入的字符串 * @return 验证结果,TRUE:正确 FALSE:错误 */ public static boolean validatePassword(String password, String inputString){ if(password.equals(encodeByMD5(inputString))){ return true; } else{ return false; } } /** 对字符串进行MD5加密 */ private static String encodeByMD5(String originString){ if (originString != null){ try{ //创建具有指定算法名称的信息摘要 MessageDigest md = MessageDigest.getInstance("MD5"); //使用指定的字节数组对摘要进行最后更新,然后完成摘要计算 byte[] results = md.digest(originString.getBytes()); //将得到的字节数组变成字符串返回 String resultString = byteArrayToHexString(results); return resultString.toUpperCase(); } catch(Exception ex){ ex.printStackTrace(); } } return null; } /** * 转换字节数组为十六进制字符串 * @param 字节数组 * @return 十六进制字符串 */ private static String byteArrayToHexString(byte[] b){ StringBuffer resultSb = new StringBuffer(); for (int i = 0; i < b.length; i++){ resultSb.append(byteToHexString(b[i])); } return resultSb.toString(); } /** 将一个字节转化成十六进制形式的字符串 */ private static String byteToHexString(byte b){ int n = b; if (n < 0) n = 256 + n; int d1 = n / 16; int d2 = n % 16; return hexDigits[d1] + hexDigits[d2]; } public static void main(String[] args) { String pwd1="abc"; String pwd2=""; String pwd3="1234"; CipherUtil cipher = new CipherUtil(); System.out.println("未加密的密码:"+pwd1); //将123加密 pwd2 = cipher.generatePassword(pwd1); System.out.println("加密后的密码:"+pwd2); System.out.print("验证密码是否下确:"); if(cipher.validatePassword(pwd2, pwd3)) { System.out.println("正确"); } else { System.out.println("错误"); } } }
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