请求第三方生成签名，用常量代替魔法值

epmet-commons/epmet-commons-thirdplat/src/main/java/com/epmet/commons/thirdplat/apiservice/jcet/JcetApiService.java

@@ -83,10 +83,10 @@ public class JcetApiService extends AbstractApiService {
 
         Map<String, String> headers = new HashMap();
         long timestamp = System.currentTimeMillis();
-        headers.put("openTimestamp", String.valueOf(timestamp));
-        headers.put("openAppId", jcetThirdplatProps.getAppkey());
+        headers.put(JcetConstants.PLAT_HEADER_OPEN_TIMESTAMP, String.valueOf(timestamp));
+        headers.put(JcetConstants.PLAT_HEADER_OPEN_APP_ID, jcetThirdplatProps.getAppkey());
         String encryptContent = jcetThirdplatProps.getAppkey() + timestamp + bodyLength;
-        headers.put("openSign", SignUtils.generate(encryptContent, jcetThirdplatProps.getAppsecret()));
+        headers.put(JcetConstants.PLAT_HEADER_OPEN_SIGN, SignUtils.generate(encryptContent, jcetThirdplatProps.getAppsecret()));
         return headers;
     }