英文:
Parsing a json datetime in revel
问题
我正在尝试从JSON请求中解析一个Datetime。请求的格式如下所示:
{
"startedAt": "2017-06-01 10:39",
...
}
被解码为以下结构体:
type MyStruct struct {
StartedAt time.Time `json:"startedAt" bson:"startedAt"`
...
}
解码行如下所示:
json.NewDecoder(c.Request.Body).Decode(&MyStruct)
Revel返回以下错误:
interface conversion: error is *time.ParseError, not *errors.Error
根据revel的文档(https://revel.github.io/manual/parameters.html),SQL标准的日期时间格式2006-01-02、2006-01-02 15:04是内置的。
在同一文档中,他们还说可以追加格式,如下所示:
func init() {
revel.TimeFormats = append(revel.TimeFormats, "01/02/2006")
}
为了验证格式是否在数组中,我尝试了以下代码:
func init() {
revel.TimeFormats = append(revel.TimeFormats, "2016-06-01 12:12")
}
在绝望之下,我尝试以revel返回JSON时间的相同格式提交:
{
"startedAt": "2017-06-22T12:22:16.265618819-05:00",
...
}
目前我不确定该怎么办。有人能够成功解析Datetime吗?
更新:我尝试了RickyA的解决方案,但现在出现了解析错误。
parsing time ""Mon, 02 Jan 2006 15:04:05 -0700"" as "Mon, 02 Jan 2006 15:04:05 -0700": cannot parse ""Mon, 02 Jan 2006 15:04:05 -0700"" as "Mon"
更奇怪的是,我实现了一个小技巧来解决这个问题。我将请求时间字段更改为字符串,并给它一个ToX函数来进行转换。该函数有效,但当它移动到UnmarshalJSON函数中时却失败了。
此外,我无法确定这是否是一个错误:
func (t *AnyTime) UnmarshalJSON(b []byte) error {
fmt.Println(time.RFC1123Z)
fmt.Println(string(b))
fmt.Println(reflect.TypeOf(time.RFC1123Z))
fmt.Println(reflect.TypeOf(string(b)))
...
这将输出:
Mon, 02 Jan 2006 15:04:05 -0700
"Mon, 02 Jan 2006 15:04:05 -0700"
string
string
请注意,只有一个字符串带有双引号。这让我相信,传递给UnmarshalJSON的字节数组中包含双引号。
最终更新:我相当确定双引号是有意的,从某种意义上讲,这是有道理的。UnmarshalJSON将从':'到','之间的所有内容传递,包括双引号。我猜这样做是为了支持整数和布尔值。我不喜欢这个解决方案,但这是我修复它的方法:
func (t *AnyTime) UnmarshalJSON(b []byte) error {
var err error
sTime := string(b)
sTime = strings.TrimSuffix(sTime, "\"")
sTime = strings.TrimPrefix(sTime, "\"")
t.Time, err = time.Parse(time.RFC1123Z, sTime)
...
英文:
I'm attempting to parse a Datetime in revel from a json request. The request looks something like this:
{
"startedAt": "2017-06-01 10:39",
...
}
The struct it's being decoded into looks like this:
type MyStruct struct {
StartedAt time.Time `json:"startedAt" bson:"startedAt"`
...
}
The decode line looks like this:
json.NewDecoder(c.Request.Body).Decode(&MyStruct)
Revel returns this error:
interface conversion: error is *time.ParseError, not *errors.Error
According to revel's documentation here, https://revel.github.io/manual/parameters.html
The SQL standard date time formats of 2006-01-02, 2006-01-02 15:04 are built in.
In the same document, they also say you can append formats like this:
func init() {
revel.TimeFormats = append(revel.TimeFormats, "01/02/2006")
}
To verify the format was in the array, I tried this:
func init() {
revel.TimeFormats = append(revel.TimeFormats, "2016-06-01 12:12")
}
In a final act of desperation I tried submitting it in the same format that revel will return json times in:
{
"startedAt": "2017-06-22T12:22:16.265618819-05:00",
...
}
At this point I'm not sure where to go with this. Has anyone been able to get revel to parse a Datetime?
Update: I tried RickyA's solution below, but now there is a parsing error.
parsing time ""Mon, 02 Jan 2006 15:04:05 -0700"" as "Mon, 02 Jan 2006 15:04:05 -0700": cannot parse ""Mon, 02 Jan 2006 15:04:05 -0700"" as "Mon"
What's even stranger is that I implemented a bit of a hack to get this working in the interrum. I changed the request time field to a string, and gave it a ToX function which converted it. That function works, but when it's moved into the UnmarshalJSON function it fails.
Also, I can't tell if this is a bug or not:
func (t *AnyTime) UnmarshalJSON(b []byte) error {
fmt.Println(time.RFC1123Z)
fmt.Println(string(b))
fmt.Println(reflect.TypeOf(time.RFC1123Z))
fmt.Println(reflect.TypeOf(string(b)))
...
This outputs this:
Mon, 02 Jan 2006 15:04:05 -0700
"Mon, 02 Jan 2006 15:04:05 -0700"
string
string
Notice that only 1 of the string has double quotes. This is leading me to believe that some how the byte array passed to UnmarshalJSON has double quotes within its string.
Final Update: So I'm pretty sure the double quotes are intentional, and in a way it makes sense. The UnmarshalJSON is passing everything from the ':' through the ',' which includes the double quotes. I'm guessing this is done so that it can also support integers and booleans. I don't like the solution, but this is how I fixed it:
func (t *AnyTime) UnmarshalJSON(b []byte) error {
var err error
sTime := string(b)
sTime = strings.TrimSuffix(sTime, "\"")
sTime = strings.TrimPrefix(sTime, "\"")
t.Time, err = time.Parse(time.RFC1123Z, sTime)
...
答案1
得分: 3
我遇到了同样的问题,最后创建了一个自定义类型来处理time.Time
。
package genericfields
import (
"encoding/json"
"time"
"strings"
"gopkg.in/mgo.v2/bson"
)
// ANYTIME //
// AnyTime接受任何时间格式进行反序列化//
type AnyTime struct{ time.Time }
func (t AnyTime) MarshalJSON() ([]byte, error) {
return json.Marshal(t.Time)
}
func (t *AnyTime) UnmarshalJSON(b []byte) error {
err := json.Unmarshal(b, &t.Time)
if err != nil { //假设输入的时间没有时区信息
bstr := strings.Trim(string(b), `"`)
t.Time, err = time.Parse("2006-01-02T15:04:05", bstr)
if err != nil {
return err //TODO 添加更多尝试的时间格式
}
}
return nil
}
func (t AnyTime) GetBSON() (interface{}, error) {
return t.Time, nil
}
func (t *AnyTime) SetBSON(raw bson.Raw) error {
var tm time.Time
err := raw.Unmarshal(&tm)
if err != nil {
return err
}
t.Time = tm.UTC()
return nil
}
func (t AnyTime) ToTime() time.Time {
return t.Time
}
用法:
type MyStruct struct {
StartedAt genericfields.AnyTime `json:"startedAt" bson:"startedAt"`
...
}
你可能需要调整time.Parse
的输入格式。
英文:
I had the same problem and ended up creating a custom type for time.Time
package genericfields
import (
"encoding/json"
"time"
"strings"
"gopkg.in/mgo.v2/bson"
)
// ANYTIME //
// AnyTime accepts any time format for its unmarshaling //
type AnyTime struct{ time.Time }
func (t AnyTime) MarshalJSON() ([]byte, error) {
return json.Marshal(t.Time)
}
func (t *AnyTime) UnmarshalJSON(b []byte) error {
err := json.Unmarshal(b, &t.Time)
if err != nil { //assume non tz time input
bstr := strings.Trim(string(b), `"`)
t.Time, err = time.Parse("2006-01-02T15:04:05", bstr)
if err != nil {
return err //TODO add more formats to try
}
}
return nil
}
func (t AnyTime) GetBSON() (interface{}, error) {
return t.Time, nil
}
func (t *AnyTime) SetBSON(raw bson.Raw) error {
var tm time.Time
err := raw.Unmarshal(&tm)
if err != nil {
return err
}
t.Time = tm.UTC()
return nil
}
func (t AnyTime) ToTime() time.Time {
return t.Time
}
Usage:
type MyStruct struct {
StartedAt genericfields.AnyTime `json:"startedAt" bson:"startedAt"`
...
}
You might need to tweak the input for time.Parse
somewhat.
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