ing

registry/registry.go

@@ -108,7 +108,7 @@ func (cr *defaultComponentRegistry) RegisterResource(name string, resource inter
 func GetInstance(t reflect.Type) (interface{}, error) {
 	return registry.GetInstance(t)
 }
-func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (interface{}, error) {
+func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (instance interface{}, err error) {
 	if nil == t {
 		return nil, fmt.Errorf("DI: t[reflect.Type] is nil")
 	}
@@ -125,7 +125,6 @@ func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (interface{}, er
 		td   *TypeDefinition
 		comV interface{}
 		ok   bool
-		err  error
 	)
 
 	rt, _, _ := cur.GetTypeInfo(t)
@@ -142,6 +141,16 @@ func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (interface{}, er
 	v := reflect.New(rt)
 	rv := v.Elem()
 
+	instance = v.Interface()
+	cr.instanceByType[td.RealType] = instance
+	err = nil
+	defer func() {
+		if nil != err {
+			instance = nil
+			delete(cr.instanceByType, td.RealType)
+		}
+	}()
+
 	var (
 		annotation cda.Annotation
 		fV         interface{}
@@ -151,15 +160,17 @@ func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (interface{}, er
 		f := rv.FieldByName(fd.FieldName)
 
 		if !f.IsValid() {
-			return nil, fmt.Errorf("DI: Field[%s] is not valid", fd.FieldName)
+			err = fmt.Errorf("DI: Field[%s] is not valid", fd.FieldName)
+			return
 		}
 		if !f.CanSet() {
-			return nil, fmt.Errorf("DI: Field[%s] can not set", fd.FieldName)
+			err = fmt.Errorf("DI: Field[%s] can not set", fd.FieldName)
+			return
 		}
 
 		if annotation = fd.GetAnnotationByType(cdia.InjectAnnotationType, false); nil != annotation {
 			if fV, err = cr.GetInstance(fd.Type); nil != err {
-				return nil, err
+				return
 			}
 		}
 
@@ -169,19 +180,17 @@ func (cr *defaultComponentRegistry) GetInstance(t reflect.Type) (interface{}, er
 				n = fd.FieldName
 			}
 			if fV, err = cr.GetInstanceByName(n); nil != err {
-				return nil, err
+				return
 			}
 		}
 
 		if nil != err {
-			return nil, fmt.Errorf("DI: %v", err)
+			return
 		}
 		f.Set(reflect.ValueOf(fV))
 	}
 
-	cr.instanceByType[td.RealType] = v.Interface()
-
-	return v.Interface(), nil
+	return
 }
 
 func GetInstanceByName(name string) (interface{}, error) {