upload download file using multipart/form-data

main.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/dutroctu/go-webservice/database"
 	"github.com/dutroctu/go-webservice/product"
+	"github.com/dutroctu/go-webservice/receipt"
 	_ "github.com/go-sql-driver/mysql"
 )
 
@@ -24,6 +25,7 @@ const apiBasePath = "/api"
 
 func main() {
 	database.SetupDatabase()
+	receipt.SetupRoutes(apiBasePath)
 	product.SetupRoutes(apiBasePath)
 
 	http.ListenAndServe(":5000", nil)

receipt/receipt.go

@@ -0,0 +1,26 @@
+package receipt
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"time"
+)
+
+var ReceiptDirectory string = filepath.Join("uploads")
+
+type Receipt struct {
+	ReceiptName string    `json:"name"`
+	UploadDate  time.Time `json:"uploadDate"`
+}
+
+func GetReceipts() ([]Receipt, error) {
+	receipts := make([]Receipt, 0)
+	files, err := ioutil.ReadDir(ReceiptDirectory)
+	if err != nil {
+		return nil, err
+	}
+	for _, f := range files {
+		receipts = append(receipts, Receipt{ReceiptName: f.Name(), UploadDate: f.ModTime()})
+	}
+	return receipts, nil
+}

receipt/receipt.service.go

@@ -0,0 +1,95 @@
+package receipt
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/dutroctu/go-webservice/cors"
+)
+
+const receiptPath = "receipts"
+
+func handleReceipts(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		receiptList, err := GetReceipts()
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+		j, err := json.Marshal(receiptList)
+		if err != nil {
+			log.Fatal(err)
+		}
+		_, err = w.Write(j)
+		if err != nil {
+			log.Fatal(err)
+		}
+	case http.MethodPost:
+		r.ParseMultipartForm(5 << 20) //5Mb
+		file, handler, err := r.FormFile("receipt")
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		defer file.Close()
+		f, err := os.OpenFile(filepath.Join(ReceiptDirectory, handler.Filename),
+			os.O_WRONLY|os.O_CREATE, 0666)
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		defer f.Close()
+		io.Copy(f, file)
+		w.WriteHeader(http.StatusCreated)
+
+	case http.MethodOptions:
+		return
+	default:
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+}
+
+func SetupRoutes(apiBasePath string) {
+	receiptHandler := http.HandlerFunc(handleReceipts)
+	downloadHandler := http.HandlerFunc(handleDownload)
+	http.Handle(fmt.Sprintf("%s/%s", apiBasePath, receiptPath), cors.Middleware(receiptHandler))
+	http.Handle(fmt.Sprintf("%s/%s/", apiBasePath, receiptPath), cors.Middleware(downloadHandler))
+}
+
+func handleDownload(w http.ResponseWriter, r *http.Request) {
+	urlPathSegments := strings.Split(r.URL.Path, fmt.Sprintf("%s/", receiptPath))
+	if len(urlPathSegments[1:]) > 1 {
+		w.WriteHeader(http.StatusBadRequest)
+		return
+	}
+	fileName := urlPathSegments[1:][0]
+	file, err := os.Open(filepath.Join(ReceiptDirectory, fileName))
+	if err != nil {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+	defer file.Close()
+	fHeader := make([]byte, 512)
+	file.Read(fHeader)
+	fContentType := http.DetectContentType(fHeader)
+	stat, err := file.Stat()
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	fSize := strconv.FormatInt(stat.Size(), 10)
+	w.Header().Set("Content-Disposition", "attachment; filename="+fileName)
+	w.Header().Set("Content-Type", fContentType)
+	w.Header().Set("Content-Length", fSize)
+	file.Seek(0, 0)
+	io.Copy(w, file)
+}