解析JSON对象的值

huangapple
go评论116阅读模式
英文:

Unmarshaling values of JSON objects

问题

可以使用Go的json包来获取edittoken。首先，需要将给定的字符串解析为JSON对象。然后，可以使用点操作符来访问嵌套的属性，以获取edittoken的值。以下是示例代码：

  1. package main
  3. import (
  4. 	"encoding/json"
  5. 	"fmt"
  6. )
  8. func main() {
  9. 	str := `{
  10. 		"query": {
  11. 			"pages": {
  12. 				"66984": {
  13. 					"pageid": 66984,
  14. 					"ns": 0,
  15. 					"title": "Main Page",
  16. 					"touched": "2012-11-23T06:44:22Z",
  17. 					"lastrevid": 1347044,
  18. 					"counter": "",
  19. 					"length": 28,
  20. 					"redirect": "",
  21. 					"starttimestamp": "2012-12-15T05:21:21Z",
  22. 					"edittoken": "bd7d4a61cc4ce6489e68c21259e6e416+\""
  23. 				}
  24. 			}
  25. 		}
  26. 	}`
  28. 	var data map[string]interface{}
  29. 	err := json.Unmarshal([]byte(str), &data)
  30. 	if err != nil {
  31. 		fmt.Println("Error:", err)
  32. 		return
  33. 	}
  35. 	edittoken := data["query"].(map[string]interface{})["pages"].(map[string]interface{})["66984"].(map[string]interface{})["edittoken"].(string)
  36. 	fmt.Println("edittoken:", edittoken)
  37. }

请注意，上述代码假设给定的字符串是有效的JSON，并且edittoken属性始终存在于相应的位置。如果JSON结构发生变化，代码可能需要进行相应的调整。

英文:

If given the string, from a MediaWiki API request:

  1. str = ` {
  2.     "query": {
  3.         "pages": {
  4.             "66984": {
  5.                 "pageid": 66984,
  6.                 "ns": 0,
  7.                 "title": "Main Page",
  8.                 "touched": "2012-11-23T06:44:22Z",
  9.                 "lastrevid": 1347044,
  10.                 "counter": "",
  11.                 "length": 28,
  12.                 "redirect": "",
  13.                 "starttimestamp": "2012-12-15T05:21:21Z",
  14.                 "edittoken": "bd7d4a61cc4ce6489e68c21259e6e416+\\"
  15.             }
  16.         }
  17.     }
  18. }`

What can be done to get the edittoken, using Go's json package (keep in mind the 66984 number will continually change)?

答案1

得分: 5

当你有一个像这样的变化的键时，处理它的最好方法是使用一个映射。在下面的示例中，我使用了结构体，直到我们达到一个变化的键的点。然后我在那之后切换到了映射格式。我也链接了一个可工作的示例。

http://play.golang.org/p/ny0kyafgYO

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"encoding/json"
  6. )
  8. type query struct {
  9. 	Query struct {
  10. 		Pages map[string]interface{}
  11. 	}
  12. }
  14. func main() {
  15. 	str := `{"query":{"pages":{"66984":{"pageid":66984,"ns":0,"title":"Main Page","touched":"2012-11-23T06:44:22Z","lastrevid":1347044,"counter":"","length":28,"redirect":"","starttimestamp":"2012-12-15T05:21:21Z","edittoken":"bd7d4a61cc4ce6489e68c21259e6e416+\"}}}}`
  17. 	q := query{}
  18. 	err := json.Unmarshal([]byte(str), &q)
  19. 	if err != nil {
  20. 		panic(err)
  21. 	}
  22. 	for _, p := range q.Query.Pages {
  23. 		fmt.Printf("edittoken = %s\n", p.(map[string]interface{})["edittoken"].(string))
  24. 	}
  25. }
英文:

When you have a changing key like this the best way to deal with it is with a map. In the example below I've used structs up until the point we reach a changing key. Then I switched to a map format after that. I linked up a working example as well.

http://play.golang.org/p/ny0kyafgYO

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"encoding/json"
  6. 	)
  8. type query struct {
  9. 	Query struct {
  10. 		Pages map[string]interface{}
  11. 	}
  12. }
  15. func main() {
  16. 	str := `{"query":{"pages":{"66984":{"pageid":66984,"ns":0,"title":"Main Page","touched":"2012-11-23T06:44:22Z","lastrevid":1347044,"counter":"","length":28,"redirect":"","starttimestamp":"2012-12-15T05:21:21Z","edittoken":"bd7d4a61cc4ce6489e68c21259e6e416+\\"}}}}`
  18. 	q := query{}
  19. 	err := json.Unmarshal([]byte(str), &q)
  20. 	if err!=nil {
  21. 		panic(err)
  22. 	}
  23. 	for _, p := range q.Query.Pages {
  24. 		fmt.Printf("edittoken = %s\n", p.(map[string]interface{})["edittoken"].(string))
  25. 	}
  26. }

答案2

得分: 4

请注意，如果您在API请求URL中使用&indexpageids=true参数，结果将包含一个名为“pageids”的数组，如下所示：

  1. str = ` {
  2.     "query": {
  3.         "pageids": [
  4.             "66984"
  5.         ],
  6.         "pages": {
  7.             "66984": {
  8.                 "pageid": 66984,
  9.                 "ns": 0,
  10.                 "title": "Main Page",
  11.                 "touched": "2012-11-23T06:44:22Z",
  12.                 "lastrevid": 1347044,
  13.                 "counter": "",
  14.                 "length": 28,
  15.                 "redirect": "",
  16.                 "starttimestamp": "2012-12-15T05:21:21Z",
  17.                 "edittoken": "bd7d4a61cc4ce6489e68c21259e6e416+\\"
  18.             }
  19.         }
  20.     }
  21. }`

因此，您可以使用pageids[0]来访问不断变化的数字，这可能会使事情变得更容易。

英文:

Note that if you use the &indexpageids=true parameter in the API request URL, the result will contain a "pageids" array, like so:

  1. str = ` {
  2.     "query": {
  3.         "pageids": [
  4.             "66984"
  5.         ],
  6.         "pages": {
  7.             "66984": {
  8.                 "pageid": 66984,
  9.                 "ns": 0,
  10.                 "title": "Main Page",
  11.                 "touched": "2012-11-23T06:44:22Z",
  12.                 "lastrevid": 1347044,
  13.                 "counter": "",
  14.                 "length": 28,
  15.                 "redirect": "",
  16.                 "starttimestamp": "2012-12-15T05:21:21Z",
  17.                 "edittoken": "bd7d4a61cc4ce6489e68c21259e6e416+\\"
  18.             }
  19.         }
  20.     }
  21. }`

so you can use pageids[0] to access the continually changing number, which will likely make things easier.

huangapple
  • 本文由 发表于 2012年12月15日 13:51:05
  • 转载请务必保留本文链接：https://go.coder-hub.com/13889745.html
  • go
  • mediawiki
  • mediawiki-api
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