Google App Engine中RPC/JSONRPC的局限性与替代方案

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"

    "google.golang.org/appengine" // For appengine.Context if needed
    "google.golang.org/appengine/datastore" // Example: using Datastore
)

// RequestPayload represents the structure of an incoming JSON request
type RequestPayload struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

// ResponsePayload represents the structure of an outgoing JSON response
type ResponsePayload struct {
    Message string `json:"message"`
    Status  string `json:"status"`
}

func init() {
    http.HandleFunc("/api/greet", greetHandler)
    http.HandleFunc("/api/save_data", saveDataHandler)
}

func greetHandler(w http.ResponseWriter, r *http.Request) {
    if r.Method != http.MethodPost {
        http.Error(w, "Only POST method is allowed", http.StatusMethodNotAllowed)
        return
    }

    var reqPayload RequestPayload
    err := json.NewDecoder(r.Body).Decode(&reqPayload)
    if err != nil {
        http.Error(w, "Invalid request payload: "+err.Error(), http.StatusBadRequest)
        return
    }

    respPayload := ResponsePayload{
        Message: fmt.Sprintf("Hello, %s! You are %d years old.", reqPayload.Name, reqPayload.Age),
        Status:  "success",
    }

    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(respPayload)
}

// Example of a handler that uses appengine.Context
func saveDataHandler(w http.ResponseWriter, r *http.Request) {
    if r.Method != http.MethodPost {
        http.Error(w, "Only POST method is allowed", http.StatusMethodNotAllowed)
        return
    }

    ctx := appengine.NewContext(r) // Get the App Engine context

    var reqPayload RequestPayload
    err := json.NewDecoder(r.Body).Decode(&reqPayload)
    if err != nil {
        http.Error(w, "Invalid request payload: "+err.Error(), http.StatusBadRequest)
        return
    }

    // Example: Save data to Datastore using the context
    key := datastore.NewIncompleteKey(ctx, "Person", nil)
    _, err = datastore.Put(ctx, key, &reqPayload) // Saving RequestPayload directly as an entity
    if err != nil {
        log.Errorf(ctx, "Failed to save data to Datastore: %v", err)
        http.Error(w, "Internal server error", http.StatusInternalServerError)
        return
    }

    respPayload := ResponsePayload{
        Message: fmt.Sprintf("Data for %s saved successfully.", reqPayload.Name),
        Status:  "success",
    }

    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(respPayload)
}