// JWT Header
private static Map<String, Object> createHeader() {
	Map<String, Object> header = new HashMap<>();
	header.put("alg","HS256");
	header.put("typ","JWT");
	return header;
}

// JWT Claims
private static Map<String, Object> createClaims(LoginVo loginVo) {
	Map<String, Object> claims = new HashMap<>();
	claims.put("email",loginVo.getEmail());
	claims.put("seq", loginVo.getUserSeq());
	claims.put("authCode", loginVo.getAuthCode());
	return claims;
}

public static Key createSigningKey() {
	byte[] apiKeySecretBytes = DatatypeConverter.parseBase64Binary(secretKey);
	return new SecretKeySpec(apiKeySecretBytes,SignatureAlgorithm.HS256.getJcaName());
}

public static String generateJwtToken(LoginVo loginVo) {
	String builder = Jwts.builder()
			// header
			.setHeader(createHeader())

			// claim
			.setSubject(loginVo.getEmail())
			.setClaims(createClaims(loginVo))
			.setIssuedAt(new Date(System.currentTimeMillis()))
			.setExpiration(createExpireDateForOneDay())
			
			// signature (HS256과 Key로 Sign)
			.signWith(SignatureAlgorithm.HS256, createSigningKey())
			
			// 토큰 생성
			.compact();
	return builder;
}