Go REST API Example

 

1. package main  
2. import (  
3.    "encoding/json"  
4.    "log"  
5.    "net/http"  
6.    "github.com/gorilla/mux"  
7. )  
8. type Employee struct {  
9.    ID        string   'json:"id,omitempty"'  
10.    Firstname string   'json:"firstname,omitempty"'  
11.    Lastname  string   'json:"lastname,omitempty"'  
12.    Address   *Address 'json:"address,omitempty"'  
13. }  
14. type Address struct {  
15.    City  string 'json:"city,omitempty"'  
16.    State string 'json:"state,omitempty"'  
17. }  
18. var emp []Employee  
19. func GetEmpIdEndpoint(w http.ResponseWriter, req *http.Request) {  
20.    params := mux.Vars(req)  
21.    for _, item := range emp {  
22.       if item.ID == params["id"] {  
23.          json.NewEncoder(w).Encode(item)  
24.          return  
25.       }  
26.    }  
27.    json.NewEncoder(w).Encode(&Employee{})  
28. }  
29. func GetEmployeeEndpoint(w http.ResponseWriter, req *http.Request) {  
30.    json.NewEncoder(w).Encode(emp)  
31. }  
32. func CreateEmployeeEndpoint(w http.ResponseWriter, req *http.Request) {  
33.    params := mux.Vars(req)  
34.    var person Employee  
35.    _ = json.NewDecoder(req.Body).Decode(&person)  
36.    person.ID = params["id"]  
37.    emp = append(emp, person)  
38.    json.NewEncoder(w).Encode(emp)  
39. }  
40. func DeleteEmployeeEndpoint(w http.ResponseWriter, req *http.Request) {  
41.    params := mux.Vars(req)  
42.    for index, item := range emp {  
43.       if item.ID == params["id"] {  
44.          emp = append(emp[:index], emp[index+1:]...)  
45.          break  
46.       }  
47.    }  
48.    json.NewEncoder(w).Encode(emp)  
49. }  
50. func main() {  
51.    router := mux.NewRouter()  
52.    emp = append(emp, Employee{ID: "1", Firstname: "Nic", Lastname: "Raboy",   
53.    Address: &Address{City: "Dublin", State: "CA"}})  
54.    emp = append(emp, Employee{ID: "2", Firstname: "Maria", Lastname: "Raboy"})  
55.    router.HandleFunc("/employee", GetEmployeeEndpoint).Methods("GET")  
56.    router.HandleFunc("/employee/{id}", GetEmpIdEndpoint).Methods("GET")  
57.    router.HandleFunc("/employee/{id}", CreateEmployeeEndpoint).Methods("POST")  
58.    router.HandleFunc("/employee/{id}", DeleteEmployeeEndpoint).Methods("DELETE")  
59.    log.Fatal(http.ListenAndServe(":12345", router))  
60. }  

Output:

You can check the output by installing postman extension for chrome browser

Method --> Get,

1.  url -->http://localhost:8080/employee  
2. Response :   
3. [{"id":"1","firstname":"James","lastname":"Johnson","address":{"city":"Hoseynabad","state":"Kavir"}}  
4. ,{"id":"2","firstname":"Sarah","lastname":"Taylor","address":{"city":"Kamenka","state":"Vyborgsky"}}]  

Method --> GET,

1.  url -->http://localhost:8080/employee/1  
2. Response :   
3. {"id":"1","firstname":"James","lastname":"Johnson","address":  
4. "city":"Hoseynabad","state":"Kavir"}}  

Method --> POST,

1. url -->http://localhost:8080/employee/3  
2. Response :   
3. [{"id":"1","firstname":"James","lastname":"Johnson","address":{"city":"Hoseynabad","state":"Kavir"}},  
4. {"id":"2","firstname":"Sarah","lastname":"Taylor","address":{"city":"Kamenka","state":"Vyborgsky"}},  
5. {"id":"3","firstname":"Roger","lastname":"Ponting","address":{"city":"San Pedro","state":"LA"}}]  

Method --> DELETE,

1. url -->http://localhost:8080/employee/2  
2. Response :   
3. [{"id":"1","firstname":"James","lastname":"Johnson","address":{"city":"Hoseynabad","state":"Kavir"}},  
4. {"id":"3","firstname":"Roger","lastname":"Ponting","address":{"city":"San Pedro","state":"LA"}}]