Why is this not dumping out the string? Anyone have any ideas how to get this code working?
package main
import (
"bytes"
"encoding/json"
"fmt"
)
type Tick struct {
Query string `json:"query"`
}
func main() {
data := &Tick{Query: "https://ratesjson.fxcm.com/DataDisplayer?&callback=Tick"}
buf := new(bytes.Buffer)
enc := json.NewEncoder(buf)
enc.SetEscapeHTML(true)
_ = enc.Encode(data)
fmt.Println(string(buf.Tick()))
fmt.Println("Done")
}
Anyone know why this is invalid json or why this can not be parsed? Or point out the fix how to make this work?
package main
import (
"log"
"fmt"
"net/http"
"bytes"
"io/ioutil"
"github.com/pquerna/ffjson/ffjson"
)
type MsgRatesArray struct {
RateQuote []MsgRateQuoteJson `json:"Rates"`
}
type MsgRateQuoteJson struct {
SymbolName string `json:"Symbol"`
SymbolBid int64 `json:"Bid"`
SymbolAsk int64 `json:"Ask"`
SymbolSpread int64 `json:"Spread"`
SymbolPT string `json:"ProductType"`
}
var respBytes []byte
func main() {
var msg MsgRatesArray
response,err := http.Get("https://ratesjson.fxcm.com/DataDisplayer?&callback=Tick")
if err != nil {
log.Fatal(err)
}
defer response.Body.Close()
respBytes, err := ioutil.ReadAll(response.Body)
jsonBytes := respBytes[bytes.Index(respBytes, []byte("{")):bytes.LastIndex(respBytes, []byte("}"))+1]
jsonString := string(jsonBytes)
fmt.Println(jsonString)
err = ffjson.Unmarshal(jsonBytes, &msg)
if err != nil {
panic(err)
}
}
Do your own http request to get the json, then strip out the non json stuff (everything before the first { and after the last }:
response,err := http.Get("https://ratesjson.fxcm.com/DataDisplayer?&callback=Tick")
if err != nil {
log.Fatal(err)
}
defer response.Body.Close()
respBytes, err := ioutil.ReadAll(response.Body)
jsonBytes := respBytes[bytes.Index(respBytes, []byte("{")):bytes.LastIndex(respBytes, []byte("}"))+1]
jsonString := string(jsonBytes)
fmt.Println(jsonString)
https://play.golang.org/p/JyibZ3g6UA
Related
I'm invoking a small API that gives back a JSON response with a Todo object. How can I display that in my Go web server? Right now, all that's displaying is 'Todo', which I hard-coded. How can that be replaced by the API JSON response?
Here is the code:
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
)
// Todo Structure
type Todo struct {
userID int
id int
title string
completed bool
}
func main() {
http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "<h1>Todo</h1>")
})
response, err := http.Get("http://jsonplaceholder.typicode.com/todos/1")
if err != nil {
fmt.Print(err.Error())
os.Exit(1)
}
responseData, err := ioutil.ReadAll(response.Body)
if err != nil {
log.Fatal(err)
}
fmt.Println(string(responseData))
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatal(err)
}
}
You have to write a function delegated to retrieve the data from the external website. Than use the http.HandleFunc in order to expose the method at your endpoint, here an example:
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
)
// Todo Structure
type Todo struct {
userID int
id int
title string
completed bool
}
func main() {
http.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, callHTTP())
})
if err := http.ListenAndServe(":8080", nil); err != nil {
log.Fatal(err)
}
}
func callHTTP() string {
var (
response *http.Response
err error
responseData []byte
)
if response, err = http.Get("http://jsonplaceholder.typicode.com/todos/1"); err != nil {
fmt.Println(err.Error())
os.Exit(1)
}
if responseData, err = ioutil.ReadAll(response.Body); err != nil {
log.Fatal(err)
}
ret := string(responseData)
fmt.Println(ret)
return ret
}
Note:
Avoid to use the default http client in production. You can try some HTTP framework like GIN. I prefer fasthttp, here you can view some code as example: https://github.com/alessiosavi/StreamingServer
I'm new in Go. I'm trying to read a JSON file and get a part of it for then operate with the values obtained.
My JSON is in the file example.json:
{"results":[{"statement_id":0,"series":[{"name":"cpu/node_utilization","columns":["time","distinct"],"values":[[10,1],[11,3],[13,5]]}]}]}
So what I would like to get is the "values" for get the sum of all the elements. In this case: 1+3+5
Here is the code that I have. I'm available to get the results, but then I don't manage to get series.
Here is the code that I have:
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
func main() {
// Open our jsonFile
jsonFile, err := os.Open("example.json")
// if we os.Open returns an error then handle it
if err != nil {
fmt.Println(err)
}
fmt.Println("Successfully Opened example.json")
// defer the closing of our jsonFile so that we can parse it later on
defer jsonFile.Close()
byteValue, _ := ioutil.ReadAll(jsonFile)
var all_data map[string]interface{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println(all_data["results"])
}
I've tried diferent solutions like
all_data["results"].(map[string]interface{})["series"])
But the problem is that the map is in an array, and I don't know how to solve it.
Using interfaces and map
package main
import (
"encoding/json"
"fmt"
)
func main() {
byteValue := []byte(`{"results":[{"statement_id":0,"series":[{"name":"cpu/node_utilization","columns":["time","distinct"],"values":[[10,1],[11,3],[13,5]]}]}]}`)
var all_data map[string][]interface{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println("result:", all_data["results"])
for _, r := range all_data["results"] {
s := r.(map[string]interface{})
fmt.Println("series:", s["series"])
w := s["series"].([]interface{})
for _, x := range w {
y := x.(map[string]interface{})
fmt.Println(y)
z := y["values"].([]interface{})
fmt.Println("values:", z)
for _, v := range z {
u := v.([]interface{})
fmt.Println(u)
for _, i := range u {
val := i.(float64)
fmt.Println(val)
}
}
}
}
}
I have solved defining an Struct.
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
)
type AutoGenerated struct {
Results []struct {
StatementID int `json:"statement_id"`
Series []struct {
Name string `json:"name"`
Columns []string `json:"columns"`
Values [][]int `json:"values"`
} `json:"series"`
} `json:"results"`
}
func main() {
// Open our jsonFile
jsonFile, err := os.Open("example.json")
// if we os.Open returns an error then handle it
if err != nil {
fmt.Println(err)
}
fmt.Println("Successfully Opened example.json")
// defer the closing of our jsonFile so that we can parse it later on
defer jsonFile.Close()
byteValue, _ := ioutil.ReadAll(jsonFile)
all_data := AutoGenerated{}
json.Unmarshal([]byte(byteValue), &all_data)
fmt.Println(all_data.Results[0].Series[0].Values)
}
I have used this web to generate automatically the Struct providing the JSON structure
I am fairly new to Go. I have the following code:
package main
import (
"encoding/json"
"fmt"
)
func main() {
byt := []byte(`{"num":6.13,"strs":["a","b"]}`)
dat := []byte(`{"num":7.13,"strs":["c","d"]}`)
if err := json.Unmarshal(byt, &dat); err != nil {
panic(err)
}
fmt.Println(dat)
}
Getting the error:
cannot "unmarshal object into Go value of type []uint8".
How can I fix this please?
You have 2 JSON inputs, and you're trying to unmarshal one into the other. That doesn't make any sense.
Model your JSON input (the object) with a type (struct), and unmarshal into that. For example:
type Obj struct {
Num float64 `json:"num"`
Strs []string `json:"strs"`
}
func main() {
byt := []byte(`{"num":6.13,"strs":["a","b"]}`)
var obj Obj
if err := json.Unmarshal(byt, &obj); err != nil {
panic(err)
}
fmt.Println(obj)
}
Output (try it on the Go Playground):
{6.13 [a b]}
I think you meant to do something like this:
package main
import (
"encoding/json"
"fmt"
)
func main() {
var dat interface{}
byt := []byte(`{"num":6.13,"strs":["a","b"]}`)
if err := json.Unmarshal(byt, &dat); err != nil {
panic(err)
}
fmt.Println(dat)
}
What you were trying to do makes no sense, since you're trying to unmarshal two JSON objects one into another.
I have used json.Unmarshal and extracted json content. I then managed to get one layer deeper into the []interface{} by using the following code:
response, err := http.Get("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=2B2A0C37AC20B5DC2234E579A2ABB11C&steamids=76561198132612090")
content, err := ioutil.ReadAll(response.Body)
defer response.Body.Close()
if err != nil {
panic(0)
}
var decoded map[string]interface{}
if err := json.Unmarshal(content, &decoded); err != nil {
panic(0)
}
players := decoded["response"].(map[string]interface{})["players"]
if err != nil {
panic(0)
}
Variable players' type is []interface {} and content is [map[personaname:Acidic]].
How do I access this map? I've tried players["personaname"] but that doesn't seem to work. Any ideas?
Defining a struct type with the expected schema will make your life easier when you want to get the data from it:
package main
import "fmt"
//import "net/http"
//import "io/ioutil"
import "encoding/json"
// you don't need to define everything, only what you need
type Player struct {
Steamid string
Communityvisibilitystate int
Personaname string
Lastlogoff int64 // time.Unix(Lastlogoff, 0)
Profileurl string
Avatar string
Avatarmedium string
Avatarfull string
Personastate int
Realname string
Primaryclanid string
Timecreated int64 // time.Unix(Timecreated, 0)
Personastateflags int
//Loccountrycode string // e.g. if you don't need this
}
func main() {
/*response, err := http.Get("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=2B2A0C37AC20B5DC2234E579A2ABB11C&steamids=76561198132612090")
if err != nil {
panic(err)
}
content, err := ioutil.ReadAll(response.Body)
defer response.Body.Close()
if err != nil {
panic(0)
}*/
content := []byte(`{
"response": {
"players": [
{
"steamid": "76561198132612090",
"communityvisibilitystate": 3,
"profilestate": 1,
"personaname": "Acidic",
"lastlogoff": 1459489924,
"profileurl": "http://steamcommunity.com/id/ari9/",
"avatar": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/bc/bc50a4065c31c606e51dfad329341b2d1f1ac4d3.jpg",
"avatarmedium": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/bc/bc50a4065c31c606e51dfad329341b2d1f1ac4d3_medium.jpg",
"avatarfull": "https://steamcdn-a.akamaihd.net/steamcommunity/public/images/avatars/bc/bc50a4065c31c606e51dfad329341b2d1f1ac4d3_full.jpg",
"personastate": 3,
"realname": "Ari Seyhun",
"primaryclanid": "103582791440552060",
"timecreated": 1397199406,
"personastateflags": 0,
"loccountrycode": "TR"
}
]
}
}`)
var decoded struct {
Response struct {
Players []Player
}
}
if err := json.Unmarshal(content, &decoded); err != nil {
panic(err)
}
fmt.Printf("%#v\n", decoded.Response.Players)
}
http://play.golang.org/p/gVPRwLFunF
You can also create a new named type from time.Time for Timecreated and Lastlogoff with its own UnmarshalJSON function, and immediately convert it to time.Time using time.Unix()
Players is a JSON array. Thus you have to convert it to a slice of interface.
Then you can access any element of the slice and casting it to a map[string]interface{} type.
Here's the working example
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
)
func main() {
response, err := http.Get("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=2B2A0C37AC20B5DC2234E579A2ABB11C&steamids=76561198132612090")
content, err := ioutil.ReadAll(response.Body)
defer response.Body.Close()
if err != nil {
panic(0)
}
var decoded map[string]interface{}
if err := json.Unmarshal(content, &decoded); err != nil {
panic(0)
}
players := decoded["response"].(map[string]interface{})["players"]
if err != nil {
panic(0)
}
sliceOfPlayers := players.([]interface{})
fmt.Println((sliceOfPlayers[0].(map[string]interface{}))["personaname"])
}
map[key:2073933158088]
I need to grab the key out of this data structure as a string, but I can't seem to figure out how!
Help with this overly simple question very much appreciated.
The value above is encapsulated in the variable named data.
I have tried: data.key, data[key], data["key"], data[0] and none of these seem to be appropriate calls.
To define data I sent up a JSON packet to a queue on IronMQ. I then pulled the message from the queue and manipulated it like this:
payloadIndex := 0
for index, arg := range(os.Args) {
if arg == "-payload" {
payloadIndex = index + 1
}
}
if payloadIndex >= len(os.Args) {
panic("No payload value.")
}
payload := os.Args[payloadIndex]
var data interface{}
raw, err := ioutil.ReadFile(payload)
if err != nil {
panic(err.Error())
}
err = json.Unmarshal(raw, &data)
Design your data type to match json structure. This is how can you achieve this:
package main
import (
"fmt"
"encoding/json"
)
type Data struct {
Key string `json:"key"`
}
func main() {
data := new(Data)
text := `{ "key": "2073933158088" }`
raw := []byte(text)
err := json.Unmarshal(raw, data)
if err != nil {
panic(err.Error())
}
fmt.Println(data.Key)
}
Since the number in the json is unquoted, it's not a string, Go will panic if you try to just handle it as a string (playground: http://play.golang.org/p/i-NUwchJc1).
Here's a working alternative:
package main
import (
"fmt"
"encoding/json"
"strconv"
)
type Data struct {
Key string `json:"key"`
}
func (d *Data) UnmarshalJSON(content []byte) error {
var m map[string]interface{}
err := json.Unmarshal(content, &m)
if err != nil {
return err
}
d.Key = strconv.FormatFloat(m["key"].(float64), 'f', -1, 64)
return nil
}
func main() {
data := new(Data)
text := `{"key":2073933158088}`
raw := []byte(text)
err := json.Unmarshal(raw, data)
if err != nil {
panic(err.Error())
}
fmt.Println(data.Key)
}
You can see the result in the playground: http://play.golang.org/p/5hU3hdV3kK