ReadWriterのテストコード

readwriter.go

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	u := &user{
		Name: "nameki",
		Age:  23,
	}

	// read
	b := make([]byte, 1024)
	n, err := u.Read(b)
	fmt.Printf("n  : %d\n", n)
	fmt.Printf("err: %s\n", err)
	fmt.Printf("string: %+s\n", b)

	// Write
	d := `{"name":"tanaka","age":10}`
	u.Write([]byte(d))
	fmt.Printf("%+v\n", u)

}

type user struct {
	Name string `json:"name"`
	Age  int    `json:"age"`
}

func (u *user) Read(p []byte) (n int, err error) {
	p, err := json.Marshal(u)
	for i, t := range b {
		p[i] = t
	}
	return len(p), err
}

func (u *user) Write(b []byte) (n int, err error) {
	err = json.Unmarshal(b, u)
	if err != nil {
		return 0, err
	}
	return len(b), err
}