enhancement code

config.go

@@ -20,6 +20,7 @@ import (
 	"path/filepath"
 	"strings"
 	"fmt"
+	"errors"
 
 	"github.com/astaxie/beego/config"
 	"github.com/astaxie/beego/session"
@@ -313,6 +314,11 @@ func LoadAppConfig(configPath string, adapterName string) error {
 	if err != nil {
 		return err
 	}
+
+	if !utils.FileExists(absConfigPath) {
+		return errors.New(fmt.Sprintf("the target config file: %s don't exist!", configPath))
+	}
+
 	if absConfigPath == AppConfigPath {
 		return nil
 	}