Extract nested values in JSON file

Question

I have this JSON file

{
  "document_tone": {
    "tone_categories": [
      {
        "category_id": "emotion_tone",
        "category_name": "Emotion Tone",
        "tones": [
          {
            "tone_id": "anger",
            "tone_name": "Anger",
            "score": 0.380012
          },
          {
            "tone_id": "disgust",
            "tone_name": "Disgust",
            "score": 0.093832
          },
          {
            "tone_id": "fear",
            "tone_name": "Fear",
            "score": 0.156902
          },
          {
            "tone_id": "joy",
            "tone_name": "Joy",
            "score": 0.204329
          },
          {
            "tone_id": "sadness",
            "tone_name": "Sadness",
            "score": 0.243196
          }
        ]
      },
      {
        "category_id": "language_tone",
        "category_name": "Language Tone",
        "tones": [
          {
            "tone_id": "analytical",
            "tone_name": "Analytical",
            "score": 0.978091
          },
          {
            "tone_id": "confident",
            "tone_name": "Confident",
            "score": 0.0
          },
          {
            "tone_id": "tentative",
            "tone_name": "Tentative",
            "score": 0.0
          }
        ]
      },
      {
        "category_id": "social_tone",
        "category_name": "Social Tone",
        "tones": [
          {
            "tone_id": "openness_big5",
            "tone_name": "Openness",
            "score": 0.453176
          },
          {
            "tone_id": "conscientiousness_big5",
            "tone_name": "Conscientiousness",
            "score": 0.707102
          },
          {
            "tone_id": "extraversion_big5",
            "tone_name": "Extraversion",
            "score": 0.856905
          },
          {
            "tone_id": "agreeableness_big5",
            "tone_name": "Agreeableness",
            "score": 0.793529
          },
          {
            "tone_id": "emotional_range_big5",
            "tone_name": "Emotional Range",
            "score": 0.835602
          }
        ]
      }
    ]
  },
  "sentences_tone": [
    {
      "sentence_id": 0,
      "input_from": 0,
      "input_to": 48,
      "text": "SVG transform on text attribute works excellent!",
      "tone_categories": [
        {
          "category_id": "emotion_tone",
          "category_name": "Emotion Tone",
          "tones": [
            {
              "tone_id": "anger",
              "tone_name": "Anger",
              "score": 0.262452
            },
            {
              "tone_id": "disgust",
              "tone_name": "Disgust",
              "score": 0.031795
            },
            {
              "tone_id": "fear",
              "tone_name": "Fear",
              "score": 0.104458
            },
            {
              "tone_id": "joy",
              "tone_name": "Joy",
              "score": 0.555167
            },
            {
              "tone_id": "sadness",
              "tone_name": "Sadness",
              "score": 0.103881
            }
          ]
        },
        {
          "category_id": "language_tone",
          "category_name": "Language Tone",
          "tones": [
            {
              "tone_id": "analytical",
              "tone_name": "Analytical",
              "score": 0.801827
            },
            {
              "tone_id": "confident",
              "tone_name": "Confident",
              "score": 0.0
            },
            {
              "tone_id": "tentative",
              "tone_name": "Tentative",
              "score": 0.0
            }
          ]
        },
        {
          "category_id": "social_tone",
          "category_name": "Social Tone",
          "tones": [
            {
              "tone_id": "openness_big5",
              "tone_name": "Openness",
              "score": 0.285863
            },
            {
              "tone_id": "conscientiousness_big5",
              "tone_name": "Conscientiousness",
              "score": 0.441621
            },
            {
              "tone_id": "extraversion_big5",
              "tone_name": "Extraversion",
              "score": 0.710666
            },
            {
              "tone_id": "agreeableness_big5",
              "tone_name": "Agreeableness",
              "score": 0.521599
            },
            {
              "tone_id": "emotional_range_big5",
              "tone_name": "Emotional Range",
              "score": 0.35773
            }
          ]
        }
      ]
    },
    {
      "sentence_id": 1,
      "input_from": 49,
      "input_to": 114,
      "text": "This snippet for example will increase your text by 2x at Y-axis.",
      "tone_categories": [
        {
          "category_id": "emotion_tone",
          "category_name": "Emotion Tone",
          "tones": [
            {
              "tone_id": "anger",
              "tone_name": "Anger",
              "score": 0.278447
            },
            {
              "tone_id": "disgust",
              "tone_name": "Disgust",
              "score": 0.137868
            },
            {
              "tone_id": "fear",
              "tone_name": "Fear",
              "score": 0.177609
            },
            {
              "tone_id": "joy",
              "tone_name": "Joy",
              "score": 0.052633
            },
            {
              "tone_id": "sadness",
              "tone_name": "Sadness",
              "score": 0.426658
            }
          ]
        },
        {
          "category_id": "language_tone",
          "category_name": "Language Tone",
          "tones": [
            {
              "tone_id": "analytical",
              "tone_name": "Analytical",
              "score": 0.932977
            },
            {
              "tone_id": "confident",
              "tone_name": "Confident",
              "score": 0.0
            },
            {
              "tone_id": "tentative",
              "tone_name": "Tentative",
              "score": 0.0
            }
          ]
        },
        {
          "category_id": "social_tone",
          "category_name": "Social Tone",
          "tones": [
            {
              "tone_id": "openness_big5",
              "tone_name": "Openness",
              "score": 0.609711
            },
            {
              "tone_id": "conscientiousness_big5",
              "tone_name": "Conscientiousness",
              "score": 0.872715
            },
            {
              "tone_id": "extraversion_big5",
              "tone_name": "Extraversion",
              "score": 0.881295
            },
            {
              "tone_id": "agreeableness_big5",
              "tone_name": "Agreeableness",
              "score": 0.881589
            },
            {
              "tone_id": "emotional_range_big5",
              "tone_name": "Emotional Range",
              "score": 0.938061
            }
          ]
        }
      ]
    }
  ]
}

I want to extract the "tones" in "document_tone" -> "tone_categories", meaning I want to extract the scores of anger, disgust, fear, joy and sadness and print them out. The first ones shown in the file.

The output should be this simple:

0.380012, 0.093832, 0.156902, 0.204329, 0.243196

I've made this code:

JSONParser parser = new JSONParser();
JSONObject jsonObject = (JSONObject) parser.parse(new FileReader("myfile.json"));
JSONObject document_tone = (JSONObject) jsonObject.get("document_tone"); 

JSONObject tone_categories = (JSONObject) document_tone.get("tone_categories");

JSONObject tones = (JSONObject) tone_categories.get("tones");

double joy = (double) tones.get("joy");
double sadness = (double) tones.get("sadness");
double disgust = (double) tones.get("disgust");
double anger = (double) tones.get("anger");
double fear = (double) tones.get("fear");

System.out.println(joy + " ;" + sadness + " ;" + disgust + " ;" + anger + " ;" + fear);

But had no success. I suspect there is something wrong in getting the nested objects one after the other.

Why you don't make a POJO class as your JSON hierarchy with same Property name in Class with get and set methods ? — Darshit, Jan 24 '17 at 15:15

score 3 · Answer 1 · answered Jan 24 '17 at 15:16

3

tone_categories is not an object but an array:

JSONArray tone_categories = (JSONArray) document_tone.get("tone_categories");

The same with tones.

answered Jan 24 '17 at 15:16

Henry

42,982
7
68
84

1

Or `document_tone.getJSONArray("tone_categories")` for type checking (assuming [org.json](https://github.com/stleary/JSON-java)) – Sean Bright Jan 24 '17 at 15:18
there are still many nested arrays and object to cover , for e.g `tones` is also an array – Pavneet_Singh Jan 24 '17 at 15:21
@PavneetSingh, he mentions that in his answer (_"The same with tones"_). – Sean Bright Jan 24 '17 at 15:25
@SeanBright there are so many other things like `sentences_tone` etc – Pavneet_Singh Jan 24 '17 at 15:27
@PavneetSingh, OK. – Sean Bright Jan 24 '17 at 15:28
can you help me with some code maybe? I've no experience with json arrays – NoobNe0 Jan 24 '17 at 18:18
and yes, I'm using org.json – NoobNe0 Jan 24 '17 at 18:20
Update: I've got a big headache, however the hint on using JSONArray sent me in the right direction and I managed to get what I wanted. – NoobNe0 Jan 25 '17 at 00:30
@NoobNe0 I just gave you a hint and not code to copy paste because it is an invaluable skill to find out things on your own. Read and understand error messages to find out what's wrong and read the documentation to do it correctly. – Henry Jan 25 '17 at 05:03
I did that and I'm glad I've made it. – NoobNe0 Jan 26 '17 at 12:46

score 0 · Answer 2 · answered Jan 24 '17 at 15:28

0

The tone_categories and tones are of type JsonArray. We can use get method to get JsonElement at a particular position or a for loop to iterate over the array elements.

answered Jan 24 '17 at 15:28

Rahul Gandhi

11
2

Extract nested values in JSON file

2 Answers2