support Go1.8 default GOPATH

router.go

@@ -17,7 +17,6 @@ package beego
 import (
 	"fmt"
 	"net/http"
-	"os"
 	"path"
 	"path/filepath"
 	"reflect"
@@ -219,13 +218,11 @@ func (p *ControllerRegister) Include(cList ...ControllerInterface) {
 		for _, c := range cList {
 			reflectVal := reflect.ValueOf(c)
 			t := reflect.Indirect(reflectVal).Type()
-			gopath := os.Getenv("GOPATH")
-			if gopath == "" {
+			wgopath := utils.GetGOPATHs()
+			if len(wgopath) == 0 {
 				panic("you are in dev mode. So please set gopath")
 			}
 			pkgpath := ""
-
-			wgopath := filepath.SplitList(gopath)
 			for _, wg := range wgopath {
 				wg, _ = filepath.EvalSymlinks(filepath.Join(wg, "src", t.PkgPath()))
 				if utils.FileExists(wg) {

utils/utils.go

+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+// GetGOPATHs returns all paths in GOPATH variable.
+func GetGOPATHs() []string {
+	gopath := os.Getenv("GOPATH")
+	if gopath == "" && strings.Compare(runtime.Version(), "go1.8") >= 0 {
+		gopath = defaultGOPATH()
+	}
+	return filepath.SplitList(gopath)
+}
+
+func defaultGOPATH() string {
+	env := "HOME"
+	if runtime.GOOS == "windows" {
+		env = "USERPROFILE"
+	} else if runtime.GOOS == "plan9" {
+		env = "home"
+	}
+	if home := os.Getenv(env); home != "" {
+		return filepath.Join(home, "go")
+	}
+	return ""
+}