Fix nil point, the make slice will import a nil object in slice

registry/etcdv3/listener.go

@@ -38,9 +38,9 @@ type dataListener struct {
 	listener      config_center.ConfigurationListener
 }
 
-// NewRegistryDataListener ...
+// NewRegistryDataListener
 func NewRegistryDataListener(listener config_center.ConfigurationListener) *dataListener {
-	return &dataListener{listener: listener, interestedURL: make([]*common.URL, 16)}
+	return &dataListener{listener: listener}
 }
 
 func (l *dataListener) AddInterestedURL(url *common.URL) {

registry/kubernetes/listener.go

@@ -39,9 +39,8 @@ type dataListener struct {
 }
 
 // NewRegistryDataListener
-// new the data  listener, the interest url default len 16
 func NewRegistryDataListener(listener config_center.ConfigurationListener) *dataListener {
-	return &dataListener{listener: listener, interestedURL: make([]*common.URL, 16)}
+	return &dataListener{listener: listener}
 }
 
 // AddInterestedURL

registry/zookeeper/listener.go

@@ -43,7 +43,7 @@ type RegistryDataListener struct {
 
 // NewRegistryDataListener ...
 func NewRegistryDataListener(listener config_center.ConfigurationListener) *RegistryDataListener {
-	return &RegistryDataListener{listener: listener, interestedURL: make([]*common.URL, 16)}
+	return &RegistryDataListener{listener: listener}
 }
 
 // AddInterestedURL ...