public static String encodeBySha256(String content) {

     String encode = "";

     try {

         MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");

         messageDigest.update(content.getBytes("UTF-8"));

         encode = bytesToHex(messageDigest.digest());

     } catch (Exception e) {

         System.out.println(e.getMessage());

     }

     return encode;

}

public static String bytesToHex(byte... src) {

    if (src == null || src.length <= 0) {

        return null;

    }

　　 StringBuilder sb = new StringBuilder();

    for (int i = 0; i < src.length; i++) {

        int value = src[i] & 0xFF;

        String hexValue = Integer.toHexString(value);

        if (hexValue.length() < 2) {

            sb.append(0);

        }

        sb.append(hexValue);

    }

    return sb.toString();

}

public static String encodeBySha256(String content) {

     String encodeString = "";

     try {

         Class<?> mdClass = Class.forName("java.security.MessageDigest");

         Method method = mdClass.getMethod("getInstance", String.class);

         MessageDigest messageDigest = (MessageDigest) method.invoke(null, "SHA-256");

         messageDigest.update(content.getBytes("UTF-8"));

         method = mdClass.getMethod("digest");

         byte[] bytes = (byte[]) method.invoke(messageDigest);

         encodeString = bytesToHex(bytes);

     } catch (Exception exception) {

         System.out.println(exception.getMessage());

     }

    return encodeString;
}