从kinesis firehose解析json

时间:2018-10-04 02:36:26

标签: json go amazon-kinesis-firehose

嗨,我正在尝试在S3上使用kinesis firehose。我试图读取那些s3文件。我正在使用GO进行阅读。

但是,我无法解析JSON,因为这些值只是追加而没有任何定界符。

这是文件的示例(请注意,原始输入是彼此追加的,为了格式化目的,我用换行符将它们分割开了):

{"ticker_symbol":"PLM","sector":"FINANCIAL","change":-0.16,"price":19.99}
{"ticker_symbol":"AZL","sector":"HEALTHCARE","change":-0.78,"price":16.51}
{"ticker_symbol":"IOP","sector":"TECHNOLOGY","change":-1.98,"price":121.88}
{"ticker_symbol":"VVY","sector":"HEALTHCARE","change":-0.56,"price":47.62}
{"ticker_symbol":"BFH","sector":"RETAIL","change":0.74,"price":16.61}
{"ticker_symbol":"WAS","sector":"RETAIL","change":-0.6,"price":16.72}

我的问题是,如何在Go中解析它?我能想到的一种解决方案是将它们除以}{,然后再次附加它们。但这确实有点黑。

运动学的软管是否提供分隔符?

------更新------

目前,我已经实现了该解决方案,将所有}{替换为},{,然后在开头添加[,在结尾添加]。然后解析它。

但是我仍在寻找替代方法,因为此解决方案会限制json对象内容中的任何}{

1 个答案:

答案 0 :(得分:2)

创建一个简单的结构以解组分批传入的json。因此,每个批处理json都将解组到json对象中。然后创建一个切片结构,将解析后的json附加到切片中。这会将结果json附加在结构片中。

package main

import (
    "encoding/json"
    "fmt"
)

type Ticker struct {
    TickerSymbol string  `json:"ticker_symbol"`
    Sector       string  `json:"sector"`
    Change       float64 `json:"change"`
    Price        float64 `json:"price"`
}

var jsonBytes = []byte(`{"ticker_symbol":"PLM","sector":"FINANCIAL","change":-0.16,"price":19.99}`)

func main() {
    var singleResult Ticker
    var result []Ticker
    if err := json.Unmarshal(jsonBytes, &singleResult); err != nil {
        fmt.Println(err)
    }

    if len(result) == 0 {
        result = append(result, singleResult)
    }
    fmt.Printf("%+v", result)
}

已编辑:

如果数据要成批包含彼此附加的json对象,则可以使用正则表达式将}替换为},,然后最右边修剪,对象的有效json数组为:

package main

import (
    "fmt"
    "regexp"
    "strings"
)

type Ticker struct {
    TickerSymbol string  `json:"ticker_symbol"`
    Sector       string  `json:"sector"`
    Change       float64 `json:"change"`
    Price        float64 `json:"price"`
}

var str = `{"ticker_symbol":"PLM","sector":"FINANCIAL","change":-0.16,"price":19.99}
{"ticker_symbol":"AZL","sector":"HEALTHCARE","change":-0.78,"price":16.51}
{"ticker_symbol":"IOP","sector":"TECHNOLOGY","change":-1.98,"price":121.88}
{"ticker_symbol":"VVY","sector":"HEALTHCARE","change":-0.56,"price":47.62}
{"ticker_symbol":"BFH","sector":"RETAIL","change":0.74,"price":16.61}
{"ticker_symbol":"WAS","sector":"RETAIL","change":-0.6,"price":16.72}`

func main() {

    r := regexp.MustCompile("}")
    output := strings.TrimRight(r.ReplaceAllString(str, "},"), ",")
    output = fmt.Sprintf("[%s]", output)
    fmt.Println(output)
}

使用r := regexp.MustCompile("}")将帮助您不必担心}{之间的空格会干扰替换字符串。因此,只需将}替换为},,然后向右修剪。

我使用MustCompile的原因是:

  

使用正则表达式创建常量时,可以使用   MustCompile编译的变体。普通编译不适用于   常量,因为它有2个返回值。

Go playground上使用json解析的完整工作代码