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有效地从JSON文件中删除无效字符?

go json

cbll · 技术社区 · 6 年前

我正在通过命令行读取一个文件。

由于该文件是从Oracle导出的JSON,因此它具有一定的结构。由于某些原因,此默认结构不是有效的JSON。例子:

// This isn't valid JSON
,"items":
[
{"id":123,"language":"ja-JP","location":"Osaka"}
,{"id":33,"language":"ja-JP","location":"Tokyo"}
,{"id":22,"language":"ja-JP","location":"Kentok"}
]}

我希望它只是一个对象数组,因此具有预期的输出:

// This is valid json
[
{"id":123,"language":"ja-JP","location":"Osaka"}
,{"id":33,"language":"ja-JP","location":"Tokyo"}
,{"id":22,"language":"ja-JP","location":"Kentok"}
]

因此,我需要删除第1行(全部)以及最后一行 } 从文件的最后一行。

正在通过命令行从输入中分析文件:

file, err := ioutil.ReadFile(os.Args[1])

// in func main()
removeInvalidJSON(file, os.Args[1])

// later on .. 
func removeInvalidJSON(file []byte, path string) {

    info, _ := os.Stat(path)
    mode := info.Mode()

    array := strings.Split(string(file), "\n")
    fmt.Println(array)

    //If we have the clunky items array which is invalid JSON, remove the first line
    if strings.Contains(array[0], "items") {
        fmt.Println("Removing items")
        array = append(array[:1], array[1+1:]...)
    }

    // Finds the last index of the array
    lastIndex := array[len(array)-1]

    // If we have the "}" in the last line, remove it as this is invalid JSON
    if strings.Contains(lastIndex, "}") {
        fmt.Println("Removing }")
        strings.Trim(lastIndex, "}")
    }

    // Nothing changed?
    fmt.Println(array)

    ioutil.WriteFile(path, []byte(strings.Join(array, "\n")), mode)
}

上面的函数确实写入了我能看到的文件-但据我所知,它不会改变数组,也不会将其写入文件。

如何有效地远程控制文件的第一行以及最后一个假大括号 } 从档案里?

我在另一个函数中解开JSON:是否有一种方法可以使用 "encoding/json" 图书馆?

1 回复 | 直到 6 年前

Adrian 6 年前

此代码有几个重要问题,导致其行为不符合预期。我已经注意到这些评论如下:

func removeInvalidJSON(file []byte, path string) {

    info, _ := os.Stat(path)
    mode := info.Mode()

    array := strings.Split(string(file), "\n")
    fmt.Println(array)

    //If we have the clunky items array which is invalid JSON, remove the first line
    if strings.Contains(array[0], "items") {
        fmt.Println("Removing items")
        // If you just want to remove the first item, this should be array = array[1:].
        // As written, this appends the rest of the array to the first item, i.e. nothing.
        array = append(array[:1], array[1+1:]...)
    }

    // Finds the last ~index~ *line* of the array
    lastIndex := array[len(array)-1]

    // If we have the "}" in the last line, remove it as this is invalid JSON
    if strings.Contains(lastIndex, "}") {
        fmt.Println("Removing }")
        // Strings are immutable. `strings.Trim` does nothing if you discard the return value
        strings.Trim(lastIndex, "}")
        // After the trim, if you want this to have any effect, you need to put it back in `array`.
    }

    // Nothing changed?
    fmt.Println(array)

    ioutil.WriteFile(path, []byte(strings.Join(array, "\n")), mode)
}

我觉得你想要的更像是:

func removeInvalidJSON(file []byte, path string) {
    info, _ := os.Stat(path)
    mode := info.Mode()

    array := strings.Split(string(file), "\n")
    fmt.Println(array)

    //If we have the clunky items array which is invalid JSON, remove the first line
    if strings.Contains(array[0], "items") {
        fmt.Println("Removing items")
        array = array[1:]
    }

    // Finds the last line of the array
    lastLine := array[len(array)-1]

    array[len(array)-1] = strings.Trim(lastLine, "}")

    fmt.Println(array)

    ioutil.WriteFile(path, []byte(strings.Join(array, "\n")), mode)
}