Java 开发中常用的 4 种加密方法

public class MD5Utils {
    private static final String hexDigIts[] = {"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
    /**     * MD5加密     * @param origin 字符     * @param charsetname 编码     * @return     */    public static String MD5Encode(String origin, String charsetname){        String resultString = null;        try{            resultString = new String(origin);            MessageDigest md = MessageDigest.getInstance("MD5");            if(null == charsetname || "".equals(charsetname)){                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));            }else{                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));            }        }catch (Exception e){        }        return resultString;    }

    public 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();    }
    public static String byteToHexString(byte b){        int n = b;        if(n < 0){            n += 256;        }        int d1 = n / 16;        int d2 = n % 16;        return hexDigIts[d1] + hexDigIts[d2];    }
}

public class Base64Util {
    // 字符串编码    private static final String UTF_8 = "UTF-8";
    /**     * 加密字符串     * @param inputData     * @return     */    public static String decodeData(String inputData) {        try {            if (null == inputData) {                return null;            }            return new String(Base64.decodeBase64(inputData.getBytes(UTF_8)), UTF_8);        } catch (UnsupportedEncodingException e) {        }        return null;    }
    /**     * 解密加密后的字符串     * @param inputData     * @return     */    public static String encodeData(String inputData) {        try {            if (null == inputData) {                return null;            }            return new String(Base64.encodeBase64(inputData.getBytes(UTF_8)), UTF_8);        } catch (UnsupportedEncodingException e) {        }        return null;    }
    public static void main(String[] args) {        System.out.println(Base64Util.encodeData("我是中文"));        String enStr = Base64Util.encodeData("我是中文");        System.out.println(Base64Util.decodeData(enStr));    }}

public class BcryptCipher {  // generate salt seed  private static final int SALT_SEED = 12;  // the head fo salt  private static final String SALT_STARTSWITH = "$2a$12";    public static final String SALT_KEY = "salt";    public static final String CIPHER_KEY = "cipher";    /**   * Bcrypt encryption algorithm method   * @param encryptSource   * need to encrypt the string   * @return Map , two values in Map , salt and cipher   */  public static Map<String, String> Bcrypt(final String encryptSource) {    String salt = BCrypt.gensalt(SALT_SEED);    Map<String, String> bcryptResult = Bcrypt(salt, encryptSource);    return bcryptResult;  }  /**   *   * @param salt encrypt salt, Must conform to the rules   * @param encryptSource   * @return   */  public static Map<String, String> Bcrypt(final String salt, final String encryptSource) {    if (StringUtils.isBlank(encryptSource)) {      throw new RuntimeException("Bcrypt encrypt input params can not be empty");    }        if (StringUtils.isBlank(salt) || salt.length() != 29) {      throw new RuntimeException("Salt can't be empty and length must be to 29");    }    if (!salt.startsWith(SALT_STARTSWITH)) {      throw new RuntimeException("Invalid salt version, salt version is $2a$12");    }        String cipher = BCrypt.hashpw(encryptSource, salt);    Map<String, String> bcryptResult = new HashMap<String, String>();    bcryptResult.put(SALT_KEY, salt);    bcryptResult.put(CIPHER_KEY, cipher);    return bcryptResult;  }  }

/** * MD5加密 */public class MD5Test {  public static void main(String[] args) {    String string = "我是一句话";    String byteArrayToHexString = MD5Utils.byteArrayToHexString(string.getBytes());    System.out.println(byteArrayToHexString);//e68891e698afe4b880e58fa5e8af9d
  }}

/** * base64加密 */public class Bast64Tester {    public static void main(String[] args) {    String string = "我是一个字符串";    String encodeData = Base64Util.encodeData(string); //加密    String decodeData = Base64Util.decodeData(encodeData); //解密    System.out.println(encodeData);//5oiR5piv5LiA5Liq5a2X56ym5Liy    System.out.println(decodeData);//我是一个字符串
  }}

/** * SHA加密 */public class ShaTest {    public static void main(String[] args) {    String string = "我是一句话";        String sha256Crypt = Sha2Crypt.sha256Crypt(string.getBytes());    System.out.println(sha256Crypt);//$5$AFoQTeyt$TiqmobvcQXjXaAQMYosAAO4KI8LfigZMGHzq.Dlp4NC
  }}

/** * BCrypt加密 */public class BCryptTest {
  public static void main(String[] args) {        String string = "我是一句话";    Map<String, String> bcrypt = BcryptCipher.Bcrypt(string);    System.out.println(bcrypt.keySet()); //[cipher, salt]        System.out.println(bcrypt.get("cipher")); //$2a$12$ylb92Z84gqlrSfzIztlCV.dK0xNbw.pOv3UwXXA76llOsNRTJsE/.    System.out.println(bcrypt.get("salt")); //$2a$12$ylb92Z84gqlrSfzIztlCV.        Map<String, String> bcrypt2 = BcryptCipher.Bcrypt(bcrypt.get("salt"),string);    System.out.println(bcrypt2.get("SALT_KEY")); //null    System.out.println(bcrypt2.get("CIPHER_KEY")); //null  }}