ObjectMapper作为常量

Author: chengyouling

clients/service-center-client/src/main/java/org/apache/servicecomb/service/center/client/DiscoveryEvents.java

@@ -27,6 +27,8 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 
 public abstract class DiscoveryEvents {
+  private final static ObjectMapper OBJECT_MAPPER = new ObjectMapper();
+
   public static class InstanceChangedEvent extends DiscoveryEvents {
     private final String appName;
 
@@ -79,8 +81,7 @@ public String getServiceName() {
 
     private JsonNode parseJsonString(String message) {
       try {
-        ObjectMapper objectMapper = new ObjectMapper();
-        return objectMapper.readTree(message);
+        return OBJECT_MAPPER.readTree(message);
       } catch (Exception e) {
         LOGGER.error("parse message [{}] failed!", message, e);
         return null;