package main

import (
    "bytes"
    "encoding/json"
    "fmt"
)

type Search struct {
    Query string `json:"query"`
}

func main() {
    data := &Search{Query: "http://google.com/?q=stackoverflow&ie=UTF-8"}
    responseJSON, _ := JSONMarshal(data, true)
    fmt.Println(string(responseJSON))

}

func JSONMarshal(v interface{}, safeEncoding bool) ([]byte, error) {
    b, err := json.Marshal(v)

    if safeEncoding {
        b = bytes.Replace(b, []byte("\\u003c"), []byte("<"), -1)
        b = bytes.Replace(b, []byte("\\u003e"), []byte(">"), -1)
        b = bytes.Replace(b, []byte("\\u0026"), []byte("&"), -1)
    }
    return b, err
}