Generate signature

Generate signature
The parameter names are sorted according to the order of the ASCII code, converted into a json string, signed with a private key, and HMAC-SHA256 encryption should be used.
Signature generation step description
First step：
Let's assume all the data sent or received to be the set M, and sort the parameters of the non-empty parameter values in the set M according to the parameter name ASCII code from small to large (dictionary order), using the format of the URL key-value pair (ie key1=value1&key2=value2) ...) stitched into a string stringA.
Pay special attention to the following important rules：
1.The parameter name ASCII code is sorted from small to large (dictionary order);
2.app_id, timestamp is a required parameter; timestamp is the last five minutes timestamp, which is invalid for more than 5 minutes;
3.If the value of the parameter is null, it does not participate in the signature;
4.Parameter names are case sensitive;
5.The transmitted sign parameter does not participate in the signature, and the generated signature will be checked based on the sign value.
The Second step：
The string is finally stitched to get the stringSignTemp string, and the stringSignTemp is programmed according to HMAC-SHA256, and then all the characters of the obtained string are converted to uppercase, then the signvalue is set.
Pseudo code example
Assume that the parameters transmitted are as follows： channelId: mttest timestamp : 1516320000 body : test
 First step: The parameters are sorted according to the key=value format and sorted according to the parameter name ASCII dictionary order as follows：
 stringA="app_id=mttest&body=test&timestamp=1516320000";
 The second step: splicing the API key:
 stringSignTemp=stringA+"&secret=my_test_secret" 
 sign=hash_hmac("sha256",stringSignTemp,key).toUpperCase()="6A9AE1657590FD6257D693A078E1C3E4BB6BA4DC30B23E0EE2496E54170DACD6" //Note: HMAC-SHA256 signature method"    
Code example
     @Test
     public void deductBalance() throws IOException {
         JTextField field ;
         String url = "http://localhost:8088/channel/deductBalance";
         TreeMap<String,Object> params = Maps.newTreeMap();
         params.put("orderId","my_order_id");
         params.put("channelId","test91021071617412");
         long timestamp = System.currentTimeMillis();
         params.put("timestamp",timestamp);
         String channelSign = getChannelSign(params, secret);
         params.put("sign",channelSign);
         System.out.println(url);
         System.out.println(JSON.toJSONString(params));
         String result = HttpUtils.sendRequestBody(url, params);
         System.out.println(result);
     }
 ​
     public static String getChannelSign(Map<String, Object> params,String secret) {
         StringBuilder result = new StringBuilder();
         if (params != null) {
             for (Object key : params.keySet()) {
                 Object value = params.get(key);
                 result.append(key).append("=").append(value).append("&");
             }
             String tempString = result + "secret=" + secret;
             try {
                 System.out.println(tempString);
                 String sign = EncryptUtils.sha256_HMAC(tempString, secret).toUpperCase();
                 System.out.println(sign);
                 return sign;
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
         return null;
     }
The parameters and order in which the code participates in encryption are：channelId=test91021071617412&orderId=my_test_id&timestamp=1547987604644&secret=my_secret
SWFT TRADE Interface
Get Account Balance
Last modified 4yr ago