URL Parameters in GoLang RESTful Web API

Install Libraries

Make sure Git is installed on your machine and in your system’s PATH. Install the packages to your $GOPATH with the go tool from shell:

$ go get -u github.com/gorilla/mux
$ go get -u github.com/gorilla/handlers

Web APIs

Create new folder named src. In src folder, create new folder named apis. In this folder, create new web api as below:

Demo API

In apis folder, create new folder named demoapi. In demoapi folder, create new go file named demo.api.go as below:

package demoapi

import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/gorilla/mux"
)

func Hello(response http.ResponseWriter, request *http.Request) {
	vars := mux.Vars(request)
	fullName := vars["fullName"]
	fmt.Fprint(response, "Hello "+fullName)
}

func Sum(response http.ResponseWriter, request *http.Request) {
	vars := mux.Vars(request)
	a := vars["a"]
	b := vars["b"]
	number1, _ := strconv.ParseInt(a, 10, 64)
	number2, _ := strconv.ParseInt(b, 10, 64)
	fmt.Fprint(response, number1+number2)
}

Structure of Project

Run Application

In src folder, create new file named main.go as below and use go run main.go command to run program:

package main

import (
	"apis/demoapi"
	"fmt"
	"net/http"

	"github.com/gorilla/mux"
)

func main() {
	router := mux.NewRouter()

	router.HandleFunc("/api/demo/hello/{fullName}", demoapi.Hello).Methods("GET")
	router.HandleFunc("/api/demo/sum/{a}/{b}", demoapi.Sum).Methods("GET")

	err := http.ListenAndServe(":3000", router)
	if err != nil {
		fmt.Println(err)
	}
}

Test Web API

Use PostMan Tool test demo web api with url: http://localhost:3000/api/demo/hello/Kevin

Use PostMan Tool test demo web api with url: http://localhost:3000/api/demo/sum/2/5