解析json與驗證

-1

我試圖從http調用解析json。對於我寫的HTTP調用，我很喜歡this 解析json與驗證

[ //list of streams 
    { 
    "entry": "stream", 
    "value": { 
     "name": "euro", //stream name 
     "urls": [ //list of sources 
     { 
      "value": "tshttp://192.168.1.2:6502", //source URL 
      "options": [ //source switching options 
      [ 
       "priority", 
       "1" 
      ], 
      [ 
       "source_timeout", 
       "30" 
      ] 
      ] 
     } 
     ], 
     "stats": { 
     "alive": true, //true if there are recent frames in the stream 
     "bitrate": 3690, //biteate 
     "bufferings": 0, 
     "client_count": 0, //number of clients (viewers) of this stream 
     "dash": true, //DASH enabled 
     "dvr_enabled": false, //archive recording disabled 
     "hds": true, //HDS enabled 
     "hls": true, //HLS enabled 
     "input_error_rate": 0, //number of errors registered per second 
     "last_access_at": 1493279230436, 
     "media_info": { //stream content info 
      "height": 576, //image height 
      "streams": [ 
      { 
       "bitrate": 191, //biteate 
       "codec": "mp2a", //codec 
       "content": "audio", //content type:audio 
       "lang": "eng", //language 
       "track_id": "a1" //track number 
      }, 
      { 
       "bitrate": 3256, //bitrate 
       "codec": "mp2v", //codec 
       "content": "video", //content type: video 
       "size": "1024x576", //image size 
       "track_id": "v1" //track number 
      } 
      ], 
      "width": 1024 //image width 
     }, 
     "out_bandwidth": 4002, //out bandwidth 
     "push_stats": { //stream copy statistisc, bytes 
      "tshttp://container4:8080/static1/mpegts": 2000918592 
     }, 
     "remote": false, //the stream is not repeated from another Flussonic 
     "retry_count": 0, //number of automatic retries 
     "running": true, //stream is being broadcased, does not necessarily mean there are frames in the stream 
     "start_running_at": 1493279194382, 
     "ts_delay": 113, //milliseconds since the most recent frame in the stream 
     "url": "tshttp://192.168.1.2:6502" //URL of current source 
     }, 
     "options": { //stream configuration 
     "static": false, 
     "retry_limit": 10, 
     "clients_timeout": 60, 
     "source_timeout": 60, 
     "pushes": [ 
      [ 
      "tshttp://container4:8080/static1/mpegts" 
      ] 
     ], 
     "publish_enabled": false, 
     "add_audio_only": false, 
     "dash_off": false, 
     "dvr_protected": false, 
     "hds_off": false, 
     "hls_off": false, 
     "m4s_off": false, 
     "mpegts_off": false, 
     "pulse_off": false, 
     "rtmp_off": false, 
     "rtsp_off": false, 
     "webrtc_off": false 
     } 
    } 
    }, 
    ... 
]

因此獲得的數據，如果我想要得到的視頻比特率，我必須這樣寫：

video_bitrate: data.value.stats.media_info.streams[1].bitrate

但有時速率值不存在，拋出異常。我不想要那個，我該如何檢查？

一個辦法是，我發現我必須寫：

if(data.hasOwnProperty('value')) { 
if (data.value.hasOwnProperty('value')) { 
    ... 
    if(data.value.stats.media_info.streams[1].hasOwnerProperty('bitrate') {...} 
} 
}

但它太長而醜陋的方式。我還可以做些什麼？

來源

2017-10-19 gsiradze

您可以使用jsonpath：

var jp = require('jsonpath'); 
var bitrates = jp.query(data, '$..streams[1].bitrate');

來源

2017-10-19 15:24:06

嘗試JavaScript的三元運算符：d https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator

const has_it = data.hasOwnProperty('value') ? true : false;

來源

2017-10-19 15:22:16

解析json與驗證

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