在Go语言中利用GAE Memcache存储结构化对象

package example

import (
    "context"
    "fmt"
    "net/http"

    "google.golang.org/appengine"
    "google.golang.org/appengine/memcache"
)

// MyCustomObject 是一个示例结构体，用于演示Memcache对象存储
type MyCustomObject struct {
    ID    int
    Name  string
    Value float64
}

func init() {
    http.HandleFunc("/memcache_object_example", handleMemcacheObjectExample)
}

func handleMemcacheObjectExample(w http.ResponseWriter, r *http.Request) {
    ctx := appengine.NewContext(r)

    // 1. 准备要存储的对象
    inObject := MyCustomObject{
        ID:    1001,
        Name:  "Example Item",
        Value: 3.14159,
    }

    // 2. 创建memcache.Item，并将对象赋值给Object字段
    itemToStore := &memcache.Item{
        Key:    "my_object_key",
        Object: inObject, // 直接存储Go对象
    }

    // 3. 使用memcache.Gob.Set()将对象存入Memcache
    // Gob Codec会自动将inObject序列化为字节数组
    if err := memcache.Gob.Set(ctx, itemToStore); err != nil {
        http.Error(w, fmt.Sprintf("Failed to set item in memcache: %v", err), http.StatusInternalServerError)
        return
    }
    fmt.Fprintf(w, "Successfully stored object: %+v\n", inObject)

    // 4. 准备一个空结构体用于接收检索到的对象
    var retrievedObject MyCustomObject

    // 5. 使用memcache.Gob.Get()从Memcache检索对象
    // Gob Codec会自动将字节数组反序列化回retrievedObject
    if err := memcache.Gob.Get(ctx, "my_object_key", &retrievedObject); err != nil {
        if err == memcache.ErrCacheMiss {
            fmt.Fprintln(w, "Object not found in memcache.")
        } else {
            http.Error(w, fmt.Sprintf("Failed to get item from memcache: %v", err), http.StatusInternalServerError)
        }
        return
    }

    // 6. 打印检索到的对象以验证
    fmt.Fprintf(w, "Successfully retrieved object: %+v\n", retrievedObject)

    // 验证数据是否一致
    if inObject.ID == retrievedObject.ID && inObject.Name == retrievedObject.Name && inObject.Value == retrievedObject.Value {
        fmt.Fprintln(w, "Retrieved object matches original object.")
    } else {
        fmt.Fprintln(w, "Retrieved object does NOT match original object.")
    }
}

// ... (MyCustomObject definition and context setup remain the same)

// 使用memcache.JSON.Set()存储对象
itemToStoreJSON := &memcache.Item{
    Key:    "my_object_key_json",
    Object: inObject,
}
if err := memcache.JSON.Set(ctx, itemToStoreJSON); err != nil {
    // ... error handling
}

// 使用memcache.JSON.Get()检索对象
var retrievedObjectJSON MyCustomObject
if err := memcache.JSON.Get(ctx, "my_object_key_json", &retrievedObjectJSON); err != nil {
    // ... error handling
}
// ...