encoding/xml: add xml encode support (#905)

* encoding/xml: add xml encode support

* encoding/xml: avoid nil pointer panic

* action: avoid go get golint pollution go.mod

.github/workflows/go.yml

@@ -24,11 +24,6 @@ jobs:
     - name: Test
       run: go test -v ./...
 
-    - name: Lint
-      run: |
-        go get golang.org/x/lint/golint
-        golint ./...
-
     - name: Kratos
       run: |
         cd cmd/kratos
@@ -52,3 +47,8 @@ jobs:
         cd examples
         go build ./...
         go test ./...
+
+    - name: Lint
+      run: |
+        go get golang.org/x/lint/golint
+        golint ./...

encoding/xml/xml.go

@@ -0,0 +1,37 @@
+package xml
+
+import (
+	"encoding/xml"
+	"reflect"
+
+	"github.com/go-kratos/kratos/v2/encoding"
+)
+
+// Name is the name registered for the xml codec.
+const Name = "xml"
+
+func init() {
+	encoding.RegisterCodec(codec{})
+}
+
+// codec is a Codec implementation with xml.
+type codec struct{}
+
+func (codec) Marshal(v interface{}) ([]byte, error) {
+	return xml.Marshal(v)
+}
+
+func (codec) Unmarshal(data []byte, v interface{}) error {
+	rv := reflect.ValueOf(v)
+	for rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			rv.Set(reflect.New(rv.Type().Elem()))
+		}
+		rv = rv.Elem()
+	}
+	return xml.Unmarshal(data, v)
+}
+
+func (codec) Name() string {
+	return Name
+}

transport/transport.go

@@ -6,6 +6,7 @@ import (
 	// init encoding
 	_ "github.com/go-kratos/kratos/v2/encoding/json"
 	_ "github.com/go-kratos/kratos/v2/encoding/proto"
+	_ "github.com/go-kratos/kratos/v2/encoding/xml"
 )
 
 // Server is transport server.