public String getAccessToken() {
    if (accessToken == null) {
        retrieveNewAccessToken();
    }

    Jwt jwt = JwtHelper.decode(accessToken);
    String claims = jwt.getClaims();
    JsonParser jsonParser = JsonParserFactory.getJsonParser();
    Map<String, Object> claimMap = jsonParser.parseMap(claims);
    Integer exp = (Integer) claimMap.get("exp");
    int now = (int) (System.currentTimeMillis() / 1000L);

    if (exp < now) {
        retrieveNewAccessToken();
    }

    return accessToken;
}
 

/**
 * 验证是否有访问权限
 * @param entity entity名称
 * @param access 访问权限： read, create, update, destroy
 * @return
 */
public boolean hasPermission(Object entity, Object access) {
    if (Strings.isNullOrEmpty(permissions)) return false;
    Map ps = JsonParserFactory.getJsonParser().parseMap(permissions);

    String entityName;
    if (entity instanceof String) {
        entityName = (String) entity;
    } else {
        entityName = (String) entity;
    }

    String permission;
    if (access instanceof Permission) {
        permission = ((Permission) access).name();
    } else {
        permission = (String) access;
    }

    if (ps.containsKey(entityName)) {
        List<String> methodNames = (List<String>) ps.get(entityName);
        return methodNames.stream().filter(m -> m.equals(permission)).count() > 0;
    }
    return false;
}
 

@JsonIgnore
public Map getPermissionsMap() {
    return Strings.isNullOrEmpty(permissions) ?
            new HashMap() : JsonParserFactory.getJsonParser().parseMap(permissions);
}
 

private String getPrivateKeyDataFromJson(String json, String serviceName) {
	JsonParser parser = JsonParserFactory.getJsonParser();
	Map<String, Object> vcapMap = parser.parseMap(json);
	return ((Map<String, String>) ((Map<String, Object>) ((List<Object>) vcapMap.get(serviceName)).get(0))
			.get("credentials")).get("PrivateKeyData");
}