diff --git a/RESTful service/monitor_update.java b/RESTful service/monitor_update.java
index 460585b..1fd5216 100644
--- a/RESTful service/monitor_update.java	
+++ b/RESTful service/monitor_update.java	
@@ -67,7 +67,7 @@ private String putHttp(String url, Map<String, String> putParams,
 
 		CloseableHttpClient httpClient = HttpClients.createDefault();
 		try {
-			HttpPut httPut = new HttpPut(url);
+			HttpPut httpPut = new HttpPut(url);
 
 			if (headerParams != null) {
 				for (String key : headerParams.keySet()) {
@@ -77,7 +77,7 @@ private String putHttp(String url, Map<String, String> putParams,
 			}
 
                         JSONObject jsonObject = JSONObject.fromObject(putParams);
-                        jsonString = jsonObject.toString();
+                        String jsonString = jsonObject.toString();
 
                         StringEntity params = new StringEntity(jsonString, "UTF-8");
                         params.setContentType("application/json");
@@ -109,12 +109,12 @@ public String update(String streamID, String streamUrl, String streamName, Strin
                          String record, String accessKey, String accessSecret){
         String result = null;
         String reqUrl = "https://api.acrcloud.com/v1/monitor-streams/"+streamID;
-        String htttMethod = "PUT";
+        String httpMethod = "PUT";
         String httpAction = "/v1/monitor-streams/"+streamID;
         String signature_version = "1";
         String timestamp = this.getUTCTimeSeconds();
 
- 		String sigStr = htttMethod + "\n" + httpAction + "\n" + accessKey
+ 		String sigStr = httpMethod + "\n" + httpAction + "\n" + accessKey
 				+ "\n" + signatureVersion + "\n" + timestamp;
 		String signature = encryptByHMACSHA1(sigStr.getBytes(),
 				accessSecret.getBytes());