如何使用Java从子jsonnode获取值

Question

I need to get codec value from jsonnode using java. The following is the jsonnode with parent and child nodes.

{  
   "DetectedProperties":{  
      "Bitrate":262610704,
      "FrameRate":"24/1",
      "FileSize":32827252,
      "Height":1080,
      "Width":1920,
      "DurationMillis":1.0,
      "codec":"prores"
   }
}

the the following code snipet doesn't return a value for codec. It always returns null.

JsonNode videoProperties = getCodecInfo(videoFile);
JsonNode videoInfo = videoProperties.get("DetectedProperties");
log.debug("codec: " + videoInfo.get("codec").toString()); // returns null

How to get the codec value from the above json using java?

Kindly provide your inputs.

Answer 1

You can use json expression "/DetectedProperties/codec" for this.

  JsonParser parser = new JsonFactory().createParser(getCodecInfo().toString());
  parser.setCodec(new ObjectMapper());
  TreeNode tree = parser.readValueAsTree();
  System.out.println(tree.at("/DetectedProperties/codec"));