How can I send request payload data using a JSON file in GO?-CodePudding

I'm really new to coding and Golang itself. I would like to know how can I send request Payload data using a JSON file in GO?

I mean, I have a post request and the JSON file and I would like to put it into the request body but I am coming across some errors.

The request is working when I use an alternative HTTP client.

CodePudding user response：

Read files: https://gobyexample.com/reading-files

HTTP client: https://zetcode.com/golang/getpostrequest/

To fully understand how go process with strings, bytes, and files, I recommand you to learn those packages:

Reading the documentations directly is hard and ineffective for begginners, you can find relative contents from Go tutorials(books or videos).

CodePudding user response：

Depending on the nature of the HTTP request, you may be able to use an existing client package. Eg, JSON RPC.

Here is an example if you would like to understand how to make a request using the standard library. This example also demonstrates using context to set timeouts for client requests:

package main

import (
    "bytes"
    "context"
    "encoding/json"
    "fmt"
    "net/http"
    "time"
)

func main() {
    ctx := context.Background()
    var client http.Client

    reqCtx, cancel := context.WithTimeout(ctx, time.Minute)
    defer cancel()
    err := deleteEntry(reqCtx, &client, 42)

    fmt.Println(err)
}

func deleteEntry(ctx context.Context, client *http.Client, entryID int) error {
    payload := &struct {
        EntryID int    `json:"entry_id"`
        Method  string `json:"method"`
    }{
        EntryID: entryID,
        Method:  "delete",
    }

    buf, err := json.Marshal(payload)
    if err != nil {
        return err
    }

    req, err := http.NewRequestWithContext(ctx, "POST", "http://localhost/example", bytes.NewReader(buf))
    if err != nil {
        return err
    }
    req.Header.Set("Content-Type", "application/json")

    resp, err := client.Do(req)
    if err != nil {
        return err
    }
    // Note: Response body must always be closed.
    // Response body data (if any) should be consumed before closure, otherwise the
    // the client connection may not be reused.
    defer resp.Body.Close()

    if resp.StatusCode != http.StatusOK {
        return fmt.Errorf("request failed with %s", resp.Status)
    }
    return nil
}

I'd recommend reading through the net/http documentation to gain a better understanding. In particular: