diff --git a/controllers/resource.go b/controllers/resource.go
index b9281595..04f4a5ad 100644
--- a/controllers/resource.go
+++ b/controllers/resource.go
@@ -64,31 +64,6 @@ func (c *ApiController) AddResource() {
 	c.ServeJSON()
 }
 
-func (c *ApiController) GetProviderParam() (*object.Provider, *object.User, bool) {
-	providerName := c.Input().Get("provider")
-	if providerName != "" {
-		provider := object.GetProvider(util.GetId(providerName))
-		if provider == nil {
-			c.ResponseError(fmt.Sprintf("The provider: %s is not found", providerName))
-			return nil, nil, false
-		}
-		return provider, nil, true
-	}
-
-	userId, ok := c.RequireSignedIn()
-	if !ok {
-		return nil, nil, false
-	}
-
-	application, user := object.GetApplicationByUserId(userId)
-	provider := application.GetStorageProvider()
-	if provider == nil {
-		c.ResponseError(fmt.Sprintf("No storage provider is found for application: %s", application.Name))
-		return nil, nil, false
-	}
-	return provider, user, true
-}
-
 func (c *ApiController) DeleteResource() {
 	var resource object.Resource
 	err := json.Unmarshal(c.Ctx.Input.RequestBody, &resource)
@@ -96,7 +71,7 @@ func (c *ApiController) DeleteResource() {
 		panic(err)
 	}
 
-	provider, _, ok := c.GetProviderParam()
+	provider, _, ok := c.GetProviderFromContext("Storage")
 	if !ok {
 		return
 	}
@@ -132,7 +107,7 @@ func (c *ApiController) UploadResource() {
 		return
 	}
 
-	provider, user, ok := c.GetProviderParam()
+	provider, user, ok := c.GetProviderFromContext("Storage")
 	if !ok {
 		return
 	}
diff --git a/controllers/util.go b/controllers/util.go
index 7b2b03a3..a7447f5e 100644
--- a/controllers/util.go
+++ b/controllers/util.go
@@ -15,9 +15,12 @@
 package controllers
 
 import (
+	"fmt"
 	"strconv"
 
 	"github.com/astaxie/beego"
+	"github.com/casbin/casdoor/object"
+	"github.com/casbin/casdoor/util"
 )
 
 // ResponseOk ...
@@ -66,3 +69,28 @@ func getInitScore() int {
 
 	return score
 }
+
+func (c *ApiController) GetProviderFromContext(category string) (*object.Provider, *object.User, bool) {
+	providerName := c.Input().Get("provider")
+	if providerName != "" {
+		provider := object.GetProvider(util.GetId(providerName))
+		if provider == nil {
+			c.ResponseError(fmt.Sprintf("The provider: %s is not found", providerName))
+			return nil, nil, false
+		}
+		return provider, nil, true
+	}
+
+	userId, ok := c.RequireSignedIn()
+	if !ok {
+		return nil, nil, false
+	}
+
+	application, user := object.GetApplicationByUserId(userId)
+	provider := application.GetProviderByCategory(category)
+	if provider == nil {
+		c.ResponseError(fmt.Sprintf("No provider for category: \"%s\" is found for application: %s", category, application.Name))
+		return nil, nil, false
+	}
+	return provider, user, true
+}
diff --git a/object/application_item.go b/object/application_item.go
index 9b5c1e70..d186ef72 100644
--- a/object/application_item.go
+++ b/object/application_item.go
@@ -14,7 +14,7 @@
 
 package object
 
-func (application *Application) getProviderByCategory(category string) *Provider {
+func (application *Application) GetProviderByCategory(category string) *Provider {
 	providers := GetProviders(application.Owner)
 	m := map[string]*Provider{}
 	for _, provider := range providers {
@@ -35,15 +35,15 @@ func (application *Application) getProviderByCategory(category string) *Provider
 }
 
 func (application *Application) GetEmailProvider() *Provider {
-	return application.getProviderByCategory("Email")
+	return application.GetProviderByCategory("Email")
 }
 
 func (application *Application) GetSmsProvider() *Provider {
-	return application.getProviderByCategory("SMS")
+	return application.GetProviderByCategory("SMS")
 }
 
 func (application *Application) GetStorageProvider() *Provider {
-	return application.getProviderByCategory("Storage")
+	return application.GetProviderByCategory("Storage")
 }
 
 func (application *Application) getSignupItem(itemName string) *SignupItem {
diff --git a/object/email.go b/object/email.go
index 21608b1c..f5c39ea6 100644
--- a/object/email.go
+++ b/object/email.go
@@ -18,7 +18,7 @@ package object
 
 import "github.com/go-gomail/gomail"
 
-func SendEmail(provider *Provider, title, content, dest, sender string) error {
+func SendEmail(provider *Provider, title string, content string, dest string, sender string) error {
 	dialer := gomail.NewDialer(provider.Host, provider.Port, provider.ClientId, provider.ClientSecret)
 
 	message := gomail.NewMessage()