英文:
ObjectIdFromHex invalid byte error on identical strings
问题
我正在尝试在我的 Golang REST API 中实现一个 FindOne 方法。问题出在当我需要通过 ID 进行搜索时。我必须将 ID 转换为数据库可读的格式，所以我使用了 primitive.ObjectIDFromHex(id) 方法。
问题是，当我使用来自 URL GET 参数的 id 调用该方法时，它会抛出一个错误：
2021/06/19 06:56:15 encoding/hex: invalid byte: U+000A
只有当我使用硬编码的 ID 调用它时，不会出现这个编码错误。请参考下面的代码。
func Admin(id string) (bson.M, error) {
coll, err := db.ConnectToCollection("admin")
if err != nil {
log.Fatal(err)
}
var admin bson.M
HardCoded := "60cb275c074ab46a1aeda45e"
fmt.Println(HardCoded) // 为了确保：这两个字符串看起来是相同的
fmt.Println(id)
objetId, err := primitive.ObjectIDFromHex(id) // 抛出编码错误
// objetId, err := primitive.ObjectIDFromHex(HardCoded) // 不会抛出编码错误
if err != nil {
log.Fatal(err)
}
var ctx = context.TODO()
if err := coll.FindOne(ctx, bson.M{"_id": objetId}).Decode(&admin); err != nil {
log.Fatal(err)
}
return admin, nil
}
当然，你可能想知道参数 id 是从哪里来的。
这是代码：
func GetAdmin(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
params := mux.Vars(r)
admin, err := Admin(params["id"]) // 调用上面的 Admin 函数
if err != nil {
fmt.Println(err)
http.Error(w, err.Error(), http.StatusUnauthorized)
} else {
JSON, err := json.Marshal(admin)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
w.Write(JSON)
}
}
英文:
I'm trying to implement a FindOne method in my Golang REST API. The trouble comes where i have to search by ID. I have to convert the ID into something readable by the database, so i use primitive.ObjectIDFromHex(id)
The problem is that this method throws an error :
2021/06/19 06:56:15 encoding/hex: invalid byte: U+000A
ONLY when i call it with the id that comes from my URL GET params.
I did two versions : one with hard-coded ID, and one with GET ID. See code below.
func Admin(id string) (bson.M, error) {
coll, err := db.ConnectToCollection("admin")
if err != nil {
log.Fatal(err)
}
var admin bson.M
HardCoded := "60cb275c074ab46a1aeda45e"
fmt.Println(HardCoded) // Just to be sure : the two strings seem identical
fmt.Println(id)
objetId, err := primitive.ObjectIDFromHex(id) // throws encoding error
// objetId, err := primitive.ObjectIDFromHex(HardCoded) // Doesnt throw encoding err
if err != nil {
log.Fatal(err)
}
var ctx = context.TODO()
if err := coll.FindOne(ctx, bson.M{"_id": objetId}).Decode(&admin); err != nil {
log.Fatal(err)
}
return admin, nil
}
Of course, you'll want to know where the param id comes from.
Here you go :
func GetAdmin(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
params := mux.Vars(r)
admin, err := Admin(params["id"]) // Calling the Admin function above
if err != nil {
fmt.Println(err)
http.Error(w, err.Error(), http.StatusUnauthorized)
} else {
JSON, err := json.Marshal(admin)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
w.Write(JSON)
}
}
答案1
得分: 3
修剪 id 结尾的换行符：
id = strings.TrimSpace(id)
在调试此类问题时，使用 %q 格式化动词。换行符在此输出中清晰可见：
fmt.Printf("%q\n", HardCoded) // 输出 "60cb275c074ab46a1aeda45e"
fmt.Printf("%q\n", id) // 输出 "60cb275c074ab46a1aeda45e\n"
英文:
Trim the line feed from the end of id:
id = strings.TrimSpace(id)
Use the %q format verb when debugging issues like this. The line feed is clearly visible in this output:
fmt.Printf("%q\n", HardCoded) // prints "60cb275c074ab46a1aeda45e"
fmt.Printf("%q\n", id) // prints "60cb275c074ab46a1aeda45e\n"
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