reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/request-body/read-json/main.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+)
+
+type Company struct {
+	Name  string
+	City  string
+	Other string
+}
+
+func MyHandler(ctx iris.Context) {
+	var c Company
+
+	if err := ctx.ReadJSON(&c); err != nil {
+		ctx.StopWithError(iris.StatusBadRequest, err)
+		return
+	}
+
+	ctx.Writef("Received: %#+v\n", c)
+}
+
+// simple json stuff, read more at https://golang.org/pkg/encoding/json
+type Person struct {
+	Name string `json:"name"`
+	Age  int    `json:"age"`
+}
+
+// MyHandler2 reads a collection of Person from JSON post body.
+func MyHandler2(ctx iris.Context) {
+	var persons []Person
+	err := ctx.ReadJSON(&persons)
+	if err != nil {
+		ctx.StopWithError(iris.StatusBadRequest, err)
+		return
+	}
+
+	ctx.Writef("Received: %#+v\n", persons)
+}
+
+func main() {
+	app := iris.New()
+
+	app.Post("/", MyHandler)
+	app.Post("/slice", MyHandler2)
+
+	// use Postman or whatever to do a POST request
+	// to the http://localhost:8080 with RAW BODY:
+	/*
+		{
+			"Name": "iris-Go",
+			"City": "New York",
+			"Other": "Something here"
+		}
+	*/
+	// and Content-Type to application/json (optionally but good practise)
+	//
+	// The response should be:
+	// Received: main.Company{Name:"iris-Go", City:"New York", Other:"Something here"}
+	app.Listen(":8080", iris.WithOptimizations)
+}