Gojmapr: Get Simple Struct from Complex JSON


gojmapr is a Golang library that allows for quick extraction of specified properties from complex JSON strings and converts them into corresponding Go structures.

With gojmapr, you don't need to declare a complete Go structure that corresponds to the entire JSON structure, just provide the required properties.

This makes gojmapr particularly useful for extracting specific data when accessing third-party resources, making your code more concise and readable.


Easy to use: Easily extract required properties from JSON strings by adding a few tags. Supports nested properties: Easily extract required properties from JSON strings with multiple nested levels.


To use gojmapr, first add it to your Golang project:

go get github.com/limiu82214/gojmapr


To use the gojmapr library, simply import it into your code and follow these steps:

Define a struct that corresponds to the JSON string you want to parse. Add the gojmapr tag to each property in the struct to specify the path to extract the property from the JSON string (reference jpath). Use the gojmapr.Unmarshal function to parse the JSON string into a struct object.


Here's a simple example that shows how to use the gojmapr library to extract properties from a JSON string.

package main

import (


func main() {
    jsonString := `{
        "user": {
            "name": "John",
            "email": "john@example.com"
        "cart": {
            "items": [
                    "product": {
                        "id": "123",
                        "name": "Product A",
                        "description": "Product A description",
                        "price": 10.99
                    "quantity": 2
                    "product": {
                        "id": "456",
                        "name": "Product B",
                        "description": "Product B description",
                        "price": 5.99
                    "quantity": 1
            "total": 27.97
        "shipping": {
            "method": "standard",
            "address": {
                "street": "123 Main St",
                "city": "Anytown",
                "state": "CA",
                "zip": "12345"
            "fee": 5.99
        "create_at": "2020-01-01T00:00:00Z"

    type tmpStruct struct {
        Name string `gojmapr:"user.name"`

    var s tmpStruct
    err := gojmapr.Unmarshal([]byte(jsonString), &s)
    if err != nil {

    fmt.Println(s.Name) // Output: John

    type tmpStruct2 struct {
        ID    string  `gojmapr:"$.cart.items[0].product.id"`
        Price float64 `gojmapr:"$.cart.items.0.product.price"`

    var s2 tmpStruct
    err := Unmarshal([]byte(jsonString), &s2)
    if err != nil {

    fmt.Println(s2.ID) // Output: 123
    fmt.Println(s2.Price) // Output: 10.99

More examples of usage can be found in the test code in the project.

Use other Unmarshal package

import jsoniter "github.com/json-iterator/go"

type tmpStruct struct {
    RequestID string `gojmapr:"$.request_id"`

SetUnmarshalFunc(jsoniter.Unmarshal) // You can use other Unmarshal module ex: json-iterator

var s tmpStruct
err := Unmarshal([]byte(jsonString), &s)
ex.Assert().Equal(ex.anserStruct.RequestID, s.RequestID)

gojmapr can use other Unmarshal package ex: json-iterator.


gojmapr uses the testify package for testing.
To run the tests, use the following command:

go test -v ./...



If you encounter any issues during use, please feel free to raise an issue on the GitHub project or contact me via email.
If you find this project helpful, please consider giving it a star.


Download Details:

Author: limiu82214
Source Code: https://github.com/limiu82214/gojmapr 
License: MIT license

#go #golang #json 

Gojmapr: Get Simple Struct from Complex JSON
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