beego: improve the static file server

@@ -383,10 +383,6 @@ func initBeforeHttpRun() {
 	middleware.AppName = AppName
 	middleware.RegisterErrorHandler()
 
-	for u, _ := range StaticDir {
-		Get(u, serverStaticRouter)
-		Get(u+"/*", serverStaticRouter)
-	}
 	if EnableDocs {
 		Get("/docs", serverDocs)
 		Get("/docs/*", serverDocs)

@@ -32,7 +32,8 @@ import (
 
 const (
 	// default filter execution points
-	BeforeRouter = iota
+	BeforeStatic = iota
+	BeforeRouter
 	BeforeExec
 	AfterExec
 	FinishRouter
@@ -577,6 +578,15 @@ func (p *ControllerRegistor) ServeHTTP(rw http.ResponseWriter, r *http.Request)
 		return false
 	}
 
+	if do_filter(BeforeStatic) {
+		goto Admin
+	}
+
+	serverStaticRouter(context)
+	if w.started {
+		goto Admin
+	}
+
 	// session init
 	if SessionOn {
 		context.Input.CruSession = GlobalSessions.SessionStart(w, r)

@@ -22,6 +22,9 @@ import (
 )
 
 func serverStaticRouter(ctx *context.Context) {
+	if ctx.Input.Method() != "GET" && ctx.Input.Method() != "HEAD" {
+		return
+	}
 	requestPath := path.Clean(ctx.Input.Request.URL.Path)
 	for prefix, staticDir := range StaticDir {
 		if len(prefix) == 0 {