public class OpenApiDemo { private static final String API_KEY = ""; private static final String API_SECRET = ""; private static final String BASE_URL = "https://openapi.bittap.com"; private static final String SEPARATOR = "&"; private static final String EQUALS = "="; private static final OkHttpClient CLIENT = new OkHttpClient(); private static final ObjectMapper MAPPER = new ObjectMapper(); public static void main(String[] args) throws Exception { String url = "https://openapi.bittap.com/fmapi/v1/time"; sendGetPublic(url); } // ----------------- Utility Methods ------------------- private static void sendSignedPost(String url, JsonNode body) throws Exception { long timestamp = System.currentTimeMillis(); String nonce = UUID.randomUUID().toString().replace("-", ""); // 1. Sort JSON JsonNode sortedNode = sortJsonNode(body); // 1. Flatten body String bodyData = convertJsonToQueryString(sortedNode); // 2. Concatenate signature string String signData = (bodyData.isEmpty() ? "" : bodyData + "&") + "timestamp=" + timestamp + "&nonce=" + nonce; String sign = hmacSha256Hex(signData, API_SECRET); String bodyJson = MAPPER.writeValueAsString(body); RequestBody requestBody = RequestBody.create(bodyJson, MediaType.parse("application/json; charset=utf-8")); Request request = new Request.Builder() .url(url) .post(requestBody) .addHeader("X-BT-APIKEY", API_KEY) .addHeader("X-BT-SIGN", sign) .addHeader("X-BT-TS", String.valueOf(timestamp)) .addHeader("X-BT-NONCE", nonce) .build(); try (Response response = CLIENT.newCall(request).execute()) { System.out.println("POST " + url); System.out.println("Response: " + response.code() + " " + (response.body() != null ? response.body().string() : "")); } } private static void sendSignedPut(String url, JsonNode body) throws Exception { long timestamp = System.currentTimeMillis(); String nonce = UUID.randomUUID().toString().replace("-", ""); // 1. Sort JSON JsonNode sortedNode = sortJsonNode(body); // 2. Flatten body String bodyData = convertJsonToQueryString(sortedNode); // 3. Concatenate signature string String signData = (bodyData.isEmpty() ? "" : bodyData + "&") + "timestamp=" + timestamp + "&nonce=" + nonce; String sign = hmacSha256Hex(signData, API_SECRET); String bodyJson = MAPPER.writeValueAsString(body); RequestBody requestBody = RequestBody.create(bodyJson, MediaType.parse("application/json; charset=utf-8")); Request request = new Request.Builder() .url(url) .put(requestBody) .addHeader("X-BT-APIKEY", API_KEY) .addHeader("X-BT-SIGN", sign) .addHeader("X-BT-TS", String.valueOf(timestamp)) .addHeader("X-BT-NONCE", nonce) .build(); try (Response response = CLIENT.newCall(request).execute()) { System.out.println("PUT " + url); System.out.println("Response: " + response.code() + " " + (response.body() != null ? response.body().string() : "")); } } private static void sendSignedPost(String url) throws Exception { long timestamp = System.currentTimeMillis(); String nonce = UUID.randomUUID().toString().replace("-", ""); String signData = "×tamp=" + timestamp + "&nonce=" + nonce; String sign = hmacSha256Hex(signData, API_SECRET); Request request = new Request.Builder() .url(url) .post(RequestBody.create("", MediaType.parse("application/json; charset=utf-8"))) .addHeader("X-BT-APIKEY", API_KEY) .addHeader("X-BT-SIGN", sign) .addHeader("X-BT-TS", String.valueOf(timestamp)) .addHeader("X-BT-NONCE", nonce) .build(); try (Response response = CLIENT.newCall(request).execute()) { System.out.println("POST " + url); System.out.println("Response: " + response.code() + " " + (response.body() != null ? response.body().string() : "")); } } private static void sendSignedGet(String url) throws Exception { long timestamp = System.currentTimeMillis(); String nonce = UUID.randomUUID().toString().replace("-", ""); // Parse existing query from URL String query = ""; int idx = url.indexOf("?"); if (idx != -1) { query = url.substring(idx + 1); } query = sortQueryParams(query); String signData = (query.isEmpty() ? "&" : query + "&") + "timestamp=" + timestamp + "&nonce=" + nonce; String sign = hmacSha256Hex(signData, API_SECRET); String finalUrl = url; Request request = new Request.Builder() .url(finalUrl) .get() .addHeader("X-BT-APIKEY", API_KEY) .addHeader("X-BT-SIGN", sign) .addHeader("X-BT-TS", String.valueOf(timestamp)) .addHeader("X-BT-NONCE", nonce) .build(); try (Response response = CLIENT.newCall(request).execute()) { System.out.println("GET " + finalUrl); System.out.println("Response: " + response.code() + " " + (response.body() != null ? response.body().string() : "")); } } private static String convertJsonToQueryString(JsonNode jsonNode) { if (jsonNode == null || jsonNode.isNull()) { return ""; } MultiValueMap params = new LinkedMultiValueMap<>(); flattenJson(jsonNode, "", params); StringBuilder queryString = new StringBuilder(); boolean first = true; for (Map.Entry entry : params.toSingleValueMap().entrySet()) { if (!first) { queryString.append("&"); } else { first = false; } queryString.append(entry.getKey()).append("=").append(entry.getValue()); } return queryString.toString(); } private static void flattenJson(JsonNode node, String path, MultiValueMap params) { if (node.isObject()) { Iterator> fields = node.fields(); while (fields.hasNext()) { Map.Entry field = fields.next(); if (field.getValue().isNull()) { continue; } String newPath = path.isEmpty() ? field.getKey() : path + "." + field.getKey(); flattenJson(field.getValue(), newPath, params); } } else if (node.isArray()) { for (int i = 0; i < node.size(); i++) { JsonNode jsonNode = node.get(i); if (jsonNode.isNull() || jsonNode.isArray() && jsonNode.isEmpty()) { continue; } String newPath = path + "[" + i + "]"; flattenJson(node.get(i), newPath, params); } } else { // Primitive type if (node.asText().isBlank()) { return; } params.add(path, node.asText()); } } private static String hmacSha256Hex(String data, String secret) throws Exception { Mac mac = Mac.getInstance("HmacSHA256"); SecretKeySpec keySpec = new SecretKeySpec(secret.getBytes(StandardCharsets.UTF_8), "HmacSHA256"); mac.init(keySpec); byte[] raw = mac.doFinal(data.getBytes(StandardCharsets.UTF_8)); StringBuilder sb = new StringBuilder(raw.length * 2); for (byte b : raw) sb.append(String.format("%02x", b)); return sb.toString(); } private static JsonNode sortJsonNode(JsonNode node) { try { if (node == null || node.isNull()) return node; if (node.isObject()) { ObjectNode out = MAPPER.createObjectNode(); TreeMap sorted = new TreeMap<>(); Iterator> fields = node.fields(); while (fields.hasNext()) { Map.Entry f = fields.next(); sorted.put(f.getKey(), sortJsonNode(f.getValue())); } for (Map.Entry e : sorted.entrySet()) { out.set(e.getKey(), e.getValue()); } return out; } else if (node.isArray()) { ArrayNode arr = MAPPER.createArrayNode(); for (JsonNode el : node) arr.add(sortJsonNode(el)); return arr; } else { return node; } } catch (Exception ex) { return node; } } private static String sortQueryParams(String query) { if (StringUtils.isBlank(query)) { return ""; } try { // Use LinkedMultiValueMap to handle parameters with the same key MultiValueMap paramMap = new LinkedMultiValueMap<>(); String[] paramPairs = query.split(SEPARATOR); for (String pair : paramPairs) { String[] keyValue = pair.split(EQUALS, 2); if (keyValue.length == 2) { paramMap.add(keyValue[0], keyValue[1]); } } // Convert MultiValueMap to Map, convert same key values to array Map convertedMap = new LinkedHashMap<>(); for (Map.Entry> entry : paramMap.entrySet()) { String key = entry.getKey(); List values = entry.getValue(); if (values.size() == 1) { convertedMap.put(key, values.get(0)); } else { convertedMap.put(key, values); } } // Use Jackson to convert Map to JsonNode JsonNode jsonNode = MAPPER.valueToTree(convertedMap); // Sort JsonNode JsonNode sortedJsonNode = sortJsonNode(jsonNode); // Convert sorted JsonNode to query string return convertJsonToQueryString(sortedJsonNode); } catch (Exception e) { return query; } }

Name	Type	Description
code	STRING	Response Code
msg	STRING	Response Message
success	BOOLEAN	Success Flag
data	INTEGER	Data Payload

Get Server Time

Request URL

Request Parameters

Response Parameters

Request Example

Response Example

Error Codes

Code Example