Question

我在java中学习json解析。我有一个json字符串，这里是

{"responseData": {
 "results": [
  {
   "GsearchResultClass": "GimageSearch",
   "width": "450",
   "height": "450",
   "imageId": "Yt3TRC1vxzhazM",
   "tbWidth": "127",
   "tbHeight": "127",
   "unescapedUrl": "http://www.touchnote.com/files/assets/STAN009.jpg",
   "url": "http://www.touchnote.com/files/assets/STAN009.jpg",
   "visibleUrl": "www.touchnote.com",
   "title": "Touchnote - Personalised \u003cb\u003eFuzzy Monkey\u003c/b\u003e greeting cards design by Dan \u003cb\u003e...\u003c/b\u003e",
   "titleNoFormatting": "Touchnote - Personalised Fuzzy Monkey greeting cards design by Dan ...",
   "originalContextUrl": "http://www.touchnote.com/photo/card-design/Fuzzy+Monkey",
   "content": "Card Design \u003cb\u003eFuzzy Monkey\u003c/b\u003e",
   "contentNoFormatting": "Card Design Fuzzy Monkey",
   "tbUrl": "http://images.google.com/images?q\u003dtbn:Yt3TRC1vxzhazM:www.touchnote.com/files/assets/STAN009.jpg"
  },
  {
   "GsearchResultClass": "GimageSearch",
   "width": "640",
   "height": "480",
   "imageId": "c6093fGTdNvKOM",
   "tbWidth": "137",
   "tbHeight": "103",
   "unescapedUrl": "http://stuff.fuzzymonkeyphotography.com/front_page/NEW_NEW_logo3_480px.jpg",
   "url": "http://stuff.fuzzymonkeyphotography.com/front_page/NEW_NEW_logo3_480px.jpg",
   "visibleUrl": "www.fuzzymonkeyphotography.com",
   "title": "\u003cb\u003eFuzzy Monkey\u003c/b\u003e Photography",
   "titleNoFormatting": "Fuzzy Monkey Photography",
   "originalContextUrl": "http://www.fuzzymonkeyphotography.com/",
   "content": "Welcome to \u003cb\u003eFuzzy Monkey\u003c/b\u003e",
   "contentNoFormatting": "Welcome to Fuzzy Monkey",
   "tbUrl": "http://images.google.com/images?q\u003dtbn:c6093fGTdNvKOM:stuff.fuzzymonkeyphotography.com/front_page/NEW_NEW_logo3_480px.jpg"
  },
  {
   "GsearchResultClass": "GimageSearch",
   "width": "500",
   "height": "375",
   "imageId": "oKdBN2qxw5JJoM",
   "tbWidth": "130",
   "tbHeight": "98",
   "unescapedUrl": "http://farm2.static.flickr.com/1104/1434841504_edc671e65c.jpg?v\u003d0",
   "url": "http://farm2.static.flickr.com/1104/1434841504_edc671e65c.jpg%3Fv%3D0",
   "visibleUrl": "www.flickr.com",
   "title": "http://farm2.static.flickr.com/1104/1434841504_edc671e65c.jpg?v\u003d0",
   "titleNoFormatting": "http://farm2.static.flickr.com/1104/1434841504_edc671e65c.jpg?v\u003d0",
   "originalContextUrl": "http://www.flickr.com/photos/maryelizajade/1434841504/in/set-72157602146748073/",
   "content": "\u003cb\u003efuzzy monkey\u003c/b\u003e",
   "contentNoFormatting": "fuzzy monkey",
   "tbUrl": "http://images.google.com/images?q\u003dtbn:oKdBN2qxw5JJoM:farm2.static.flickr.com/1104/1434841504_edc671e65c.jpg%3Fv%3D0"
  },
  {
   "GsearchResultClass": "GimageSearch",
   "width": "500",
   "height": "375",
   "imageId": "GNgM5anX5NZYPM",
   "tbWidth": "130",
   "tbHeight": "98",
   "unescapedUrl": "http://farm1.static.flickr.com/38/91607831_009166aa41.jpg",
   "url": "http://farm1.static.flickr.com/38/91607831_009166aa41.jpg",
   "visibleUrl": "www.flickr.com",
   "title": "\u003cb\u003eFuzzy monkey\u003c/b\u003e sad face on Flickr - Photo Sharing!",
   "titleNoFormatting": "Fuzzy monkey sad face on Flickr - Photo Sharing!",
   "originalContextUrl": "http://www.flickr.com/photos/ajagendorf25/91607831/",
   "content": "\u003cb\u003eFuzzy monkey\u003c/b\u003e sad face",
   "contentNoFormatting": "Fuzzy monkey sad face",
   "tbUrl": "http://images.google.com/images?q\u003dtbn:GNgM5anX5NZYPM:farm1.static.flickr.com/38/91607831_009166aa41.jpg"
  }
 ],
 "cursor": {
  "pages": [
   {
    "start": "0",
    "label": 1
   },
   {
    "start": "4",
    "label": 2
   },
   {
    "start": "8",
    "label": 3
   },
   {
    "start": "12",
    "label": 4
   },
   {
    "start": "16",
    "label": 5
   },
   {
    "start": "20",
    "label": 6
   },
   {
    "start": "24",
    "label": 7
   },
   {
    "start": "28",
    "label": 8
   }
  ],
  "estimatedResultCount": "578000",
  "currentPageIndex": 0,
  "moreResultsUrl": "http://www.google.com/images?oe\u003dutf8\u0026ie\u003dutf8\u0026source\u003duds\u0026start\u003d0\u0026hl\u003den\u0026q\u003dfuzzy+monkey"
 }
}
, "responseDetails": null, "responseStatus": 200}

我将此作为谷歌图片搜索API的回复

这是它的链接

https://developers.google.com/image-search/v1/jsondevguide

但是当我尝试解析它时，我总是失败而没有结果。

这是我的代码

JSONObject json = new JSONObject(builder.toString());

            final JSONArray geodata = json.getJSONArray("results");
            final int n = geodata.length();
            for (int i = 0; i < n; ++i) {
              final JSONObject person = geodata.getJSONObject(i);

             System.out.println(person.geString("width"));
            }

任何人都可以告诉我，我在哪里做错了。非常感谢任何帮助。谢谢:)）

Answer 1

JSONObject json = new JSONObject(builder.toString());
//Add this line 
JSONObject responseData = json.getJSONObject("responseData");
        final JSONArray geodata = responseData.getJSONArray("results");
        final int n = geodata.length();
        for (int i = 0; i < n; ++i) {
          final JSONObject person = geodata.getJSONObject(i);

         System.out.println(person.geString("width"));
        }

Answer 2

 JSONParser parser=new JSONParser();
 Object obj = parser.parse(builder.toString());
 JSONArray array = (JSONArray)obj;
 System.out.println("The 2nd element of array");
 System.out.println(array.get(1));
 JSONObject obj2 = (JSONObject)array.get(1);

尝试这种方法。

Answer 3

您可以使用Java API进行JSON处理（JSR-353）来解析JSON。该标准提供了基于流（如StAX for XML）和基于对象（如DOM的XML，但更轻）。

了解更多信息

以下是我的博客的几个链接，详细说明了如何使用这些API：

Answer 4

要将您的 JSON字符串转换为哈希图，请使用：

HashMap<String, Object> hashMap = new HashMap<>(Utility.jsonToMap(response)) ;

使用此类：）（甚至处理列表，嵌套列表和json）

public class Utility {

    public static Map<String, Object> jsonToMap(Object json) throws JSONException {

        if(json instanceof JSONObject)
            return _jsonToMap_((JSONObject)json) ;

        else if (json instanceof String)
        {
            JSONObject jsonObject = new JSONObject((String)json) ;
            return _jsonToMap_(jsonObject) ;
        }
        return null ;
    }


   private static Map<String, Object> _jsonToMap_(JSONObject json) throws JSONException {
        Map<String, Object> retMap = new HashMap<String, Object>();

        if(json != JSONObject.NULL) {
            retMap = toMap(json);
        }
        return retMap;
    }


    private static Map<String, Object> toMap(JSONObject object) throws JSONException {
        Map<String, Object> map = new HashMap<String, Object>();

        Iterator<String> keysItr = object.keys();
        while(keysItr.hasNext()) {
            String key = keysItr.next();
            Object value = object.get(key);

            if(value instanceof JSONArray) {
                value = toList((JSONArray) value);
            }

            else if(value instanceof JSONObject) {
                value = toMap((JSONObject) value);
            }
            map.put(key, value);
        }
        return map;
    }


    public static List<Object> toList(JSONArray array) throws JSONException {
        List<Object> list = new ArrayList<Object>();
        for(int i = 0; i < array.length(); i++) {
            Object value = array.get(i);
            if(value instanceof JSONArray) {
                value = toList((JSONArray) value);
            }

            else if(value instanceof JSONObject) {
                value = toMap((JSONObject) value);
            }
            list.add(value);
        }
        return list;
    }
}

如何在java中解析json字符串

4 个答案: