将文件内容存入多维字符串变量中。

huangapple
go评论115阅读模式
英文:

Getting file content into a multidimensional string var

问题

我正在使用fsnotify包来等待json文件的更改。

我在这段代码中遇到了两个问题。第一个问题是关于ReadFile函数返回的信息。当我打印函数返回的内容时，似乎是空的。

第二个问题是关于fsnotify在第一次读取文件时不起作用，除非我对内容进行一些修改。我也必须从开头读取文件。

  1. type Information struct {
  2.     Info []Info `json:"info"`
  3. }
  5. type Info struct {
  6.     Type string `json:"type"`
  7.     News []New  `json:"news"`
  8. }
  10. type New struct {
  11.     Name string `json:"name"`
  12.     Read bool   `json:"read"`
  13. }
  15. func ReadFile(file_name string) *Information {
  16.     jsonFile, err := os.Open(file_name)
  17.     if err != nil {
  18.         fmt.Println(err)
  19.     }
  20.     fmt.Println("Successfully Opened file_name.json")
  22.     defer jsonFile.Close()
  24.     byteValue, _ := ioutil.ReadAll(jsonFile)
  26.     var infor Information
  28.     json.Unmarshal(byteValue, &infor)
  30.     return &infor
  31. }
  33. // 主函数
  34. func main() {
  35.    // 使用fsnotify读取json文件并等待更改
  36. 	watcher, err := fsnotify.NewWatcher()
  38. 	if err != nil {
  39. 		panic(err)
  40. 	}
  42. 	err = watcher.Add(file_json)
  43. 	if err != nil {
  44. 		panic(err)
  45. 	}
  47. 	for {
  48. 		select {
  49. 		case ev, ok := <-watcher.Events:
  50. 			log.Println("event:", ev)
  51. 			if !ok {
  52. 				return
  53. 			}
  54. 			if ev.Op&fsnotify.Write == fsnotify.Write {
  56. 				data := ReadFile(file_name)
  57. 				fmt.Print("文件信息：\n") 
  59. 				for _, info := range data.Info {
  60.                     fmt.Printf("信息类型：%s\n", info.Type) // 这里没有打印info.Type的结果
  61. 					for _, news := range info.News {
  62. 						fmt.Printf("新闻名称：%s\n", news.Name) // 这里甚至没有打印"新闻名称："或"新闻已读："
  63.                         fmt.Printf("新闻已读：%s\n", strconv.FormatBool(news.Read))
  64. 					}
  65. 				}
  66. 			}
  67. 		case err := <-watcher.Errors:
  68. 			log.Println("错误：", err)
  69. 		}
  70.     }
  71. }

这是json文件的内容：

  1. {
  2.     "info": [
  3.         {
  4.             "type": "general",
  5.             "news": [
  6.                 { "name": "abc", "read": true },
  7.                 { "name": "def", "read": true }
  8.             ]
  9.         },
  10.         {
  11.             "type": "confidential",
  12.             "news": [
  13.                 { "name": "xxx", "read": false },
  14.                 { "name": "yyy", "read": false }
  15.             ]
  16.         }
  17.     ]
  18. }
英文:

I'm using the fsnotify packet to wait for changes in a json file.

I have two problems with this code. The first one is regarding the info returned by ReadFile function. Looks like when I print something returned by the function is empty.

Second issue is regarding the fsnotify that is not reading the file the first time unless i do some modification on the content. I must read the file from the beggining as well.

  1. type Information struct {
  2. Info []Info `json:&quot;info&quot;`
  3. }
  4. type Info struct {
  5. Type string `json:&quot;type&quot;`
  6. News []New  `json:&quot;news&quot;`
  7. }
  8. type New struct {
  9. Name string `json:&quot;name&quot;`
  10. Read bool   `json:&quot;read&quot;`
  11. }
  12. func ReadFile(file_name string) *Information {
  13. jsonFile, err := os.Open(file_name)
  14. if err != nil {
  15. fmt.Println(err)
  16. }
  17. fmt.Println(&quot;Successfully Opened file_name.json&quot;)
  18. defer jsonFile.Close()
  19. byteValue, _ := ioutil.ReadAll(jsonFile)
  20. var infor Information
  21. json.Unmarshal(byteValue, &amp;infor)
  22. return &amp;infor
  23. }
  24. // main function
  25. func main() {
  26. // read json file using fsnotify to wait for changes
  27. watcher, err := fsnotify.NewWatcher()
  28. if err != nil {
  29. panic(err)
  30. }
  31. err = watcher.Add(file_json)
  32. if err != nil {
  33. panic(err)
  34. }
  35. for {
  36. select {
  37. case ev, ok := &lt;-watcher.Events:
  38. log.Println(&quot;event:&quot;, ev)
  39. if !ok {
  40. return
  41. }
  42. if ev.Op&amp;fsnotify.Write == fsnotify.Write {
  43. data := ReadFile(file_name)
  44. fmt.Print(&quot;INFORMATION ABOUT FILE:\n&quot;) 
  45. for _, info := range data.Info {
  46. fmt.Printf(&quot;Info type: %s\n&quot;, info.Type) // Here is not printing the result of info.Type
  47. for _, news := range info.News {
  48. fmt.Printf(&quot;News Name: %s\n&quot;, news.Name) // Here is not printing even &quot;News Name:&quot; or News Read:&quot;
  49. fmt.Printf(&quot;News Read: %s\n&quot;, strconv.FormatBool(news.Read))
  50. }
  51. }
  52. }
  53. case err := &lt;-watcher.Errors:
  54. log.Println(&quot;error:&quot;, err)
  55. }
  56. }
  57. }

This is the json file:

  1. {
  2. &#160;&#160;&#160; &quot;info&quot;: [
  3. &#160;&#160;&#160;&#160;&#160; {
  4. &#160;&#160;&#160;&#160;&#160;&#160;&#160; &quot;type&quot;: &quot;general&quot;,
  5. &#160;&#160;&#160;&#160;&#160;&#160;&#160; &quot;news&quot;: [
  6. &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; { &quot;name&quot;: &quot;abc&quot;,&#160; &quot;read&quot;: true },
  7. &#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; { &quot;name&quot;: &quot;def&quot;,&#160; &quot;read&quot;: true }
  8. &#160;&#160;&#160;&#160;&#160;&#160;&#160; ]
  9. &#160;&#160;&#160;&#160;&#160; },
  10. {
  11. &quot;type&quot;: &quot;confidential&quot;,
  12. &quot;news&quot;: [
  13. { &quot;name&quot;: &quot;xxx&quot;,  &quot;read&quot;: false },
  14. { &quot;name&quot;: &quot;yyy&quot;,  &quot;read&quot;: false }
  15. ]
  16. },
  17. ]
  18. }

答案1

得分: 1

  1. type Information struct {
  2. 	Info []Info `json:"info"`
  3. }
  5. type Info struct {
  6. 	Type string `json:"type"`
  7. 	News []New  `json:"news"` // 这里应该是一个切片定义。
  8. }
  10. type New struct {
  11. 	Name string `json:"name"`
  12. 	Read bool   `json:"read"`
  13. }
  15. func ReadFile(file_name string) *Information {
  16. 	jsonFile, err := os.Open(file_name)
  17. 	if err != nil {
  18. 		fmt.Println(err)
  19. 	}
  20. 	fmt.Println("成功打开文件 file_name.json")
  22. 	defer jsonFile.Close()
  24. 	byteValue, _ := ioutil.ReadAll(jsonFile)
  26. 	var infor Information
  28. 	json.Unmarshal(byteValue, &infor)
  30. 	return &infor
  31. }
  1. func main() {
  2. 	data := ReadFile("./data.json")
  3. 	for _, news := range data.Info {
  4. 		for _, v := range news.News {
  5. 			name := v.Name
  6. 			// 添加你想要做的操作
  7. 			fmt.Println(name)
  8. 		}
  9. 	}
  10. }

你不能得到这样的结果：

  1. getInfo = [general][abc, true, def, true]
  2. [confidential][xxx, false, yyy, false]
英文: 
  1. type Information struct {
  2. 	Info []Info `json:&quot;info&quot;`
  3. }
  5. type Info struct {
  6. 	Type string `json:&quot;type&quot;`
  7. 	News []New  `json:&quot;news&quot;` // Here should be a slice define.
  8. }
  10. type New struct {
  11. 	Name string `json:&quot;name&quot;`
  12. 	Read bool   `json:&quot;read&quot;`
  13. }
  15. func ReadFile(file_name string) *Information {
  16. 	jsonFile, err := os.Open(file_name)
  17. 	if err != nil {
  18. 		fmt.Println(err)
  19. 	}
  20. 	fmt.Println(&quot;Successfully Opened file_name.json&quot;)
  22. 	defer jsonFile.Close()
  24. 	byteValue, _ := ioutil.ReadAll(jsonFile)
  26. 	var infor Information
  28. 	json.Unmarshal(byteValue, &amp;infor)
  30. 	return &amp;infor
  31. }
  1. func main() {
  2. 	data := ReadFile(&quot;./data.json&quot;)
  3. 	for _, news := range data.Info {
  4. 		for _, v := range news.News {
  5. 			name := v.Name
  6. 			// Add you want to do
  7. 			fmt.Println(name)
  8. 		}
  9. 	}
  10. }

You can not get like this:

  1. getInfo = [general][abc, true, def, true]
  2. [confidential][xxx, false, yyy, false]

huangapple
  • 本文由 发表于 2022年6月27日 19:03:12
  • 转载请务必保留本文链接：https://go.coder-hub.com/72771038.html
  • arrays
  • go
  • json
  • multidimensional-array
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