Android-json解析(三):原生JSONObject+JSONArray的解析、遍历及生成等

Android-json解析(三):原生JSONObject+JSONArray的解析、遍历及生成等一、JSONObject和JSONArray的数据表示形式JSONObject的数据是用{}来表示的,例如:{"id":"123",

Android-Gson+GsonFormat的导入
Android-json解析(一):Gson的使用
Android-json解析(二):Jackson的使用
Android-json解析(三):原生JSONObject+JSONArray的使用
Android-json解析(四):fastjson的使用

Android -序列化 : Serializable / Parcelable

一、JSONObject和JSONArray的数据表示形式

JSONObject的数据是用 { } 来表示的,

例如:

{ 
   
    "id":"1",
    "courseID":"化学",
    "title":"滴定实验",
    "content":"下周二实验楼201必须完成"
}

而JSONArray,顾名思义是由JSONObject构成的数组,用 [ { } , { } , … , { } ] 来表示

例如:

[
    { 
   
        "id":"1",
        "courseID":"数学",
        "title":"一加一等于几"
    },
    { 
   
        "id":"2",
        "courseID":"语文",
        "title":"请背诵全文"
    }
] 

表示了包含2个JSONObject的JSONArray。

可以看到一个很明显的区别,一个最外面用的是 { } ,一个最外面用的是 [ ] ;

二、如何从字符串jsonString获得JSONObject对象和JSONArray对象

/*json字符串最外层是大括号时:*/
JSONObject jsonObject = new JSONObject(jsonStr);

/*json字符串最外层是方括号时:*/
JSONArray jsonArray = new JSONArray(jsonStr);

三、如何从JSONArray中获得JSONObject对象

遇到方括号时,就要先获取JSONArray,然后再循环遍历出JSONObject

大家可以把JSONArray当成一般的数组来对待,只是获取的数据内数据的方法不一样。

 for (int i = 0; i < jsonArray.length(); i++) { 
   
    JSONObject jsonObject = jsonArray.getJSONObject(i);
 }

注意:

/*JSONObject 获取jsonArray :需要数组的字段名*/
JSONArray jsonArray = jsonObject.getJSONArray("children");


/*jsonArray获取JSONObject : 需要遍历数组*/
 for (int i = 0; i < jsonArray.length(); i++) { 
   
    JSONObject jsonObject = jsonArray.getJSONObject(i);
 }

四、通过JsonObject获取JSON内的具体数据:

int mid= jsonObject.getInt("id");    

String mcourse=jsonObject.getString("courseID");   

示例一:

{ 
   
  "msg": "",
  "code": "succeed",
  "login_status": 0,
  "mall_uid": "epet_0",
  "mall_user": "",
  "sys_time": 1494388655,
  "push_alias": "",
  "push_tags": "version3",
  "categorys": [
    { 
   
      "cateid": 53,
      "name": "狗狗玩具",
      "children": [
        { 
   
          "type": "cateid",
          "id": "210",
          "name": "棉制玩具",
          "photo": "http://i.epetbar.com/nowater/cates/2014-03/24/fcab37ead00d77bcdddf7dabe6c817d7.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "211",
          "name": "橡胶玩具",
          "photo": "http://i.epetbar.com/nowater/2016-07/21/14/874299e54a8cf1488d6b1bead8f8e9bb.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "212",
          "name": "塑料玩具",
          "photo": "http://i.epetbar.com/nowater/cates/2014-03/24/df1ed7120376370a4b5badaae61a0a7e.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "213",
          "name": "手工玩具",
          "photo": "http://i.epetbar.com/nowater/cates/2014-03/24/6709410560b999ab37ffb9747bb2ee71.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "3088",
          "name": "食用玩具",
          "photo": "http://i.epetbar.com/nowater/cates/2014-03/24/a5c7619872749790f6d6fd1ff3eccedc.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "4157",
          "name": "木质玩具",
          "photo": "http://i.epetbar.com/nowater/cates/2014-03/24/e9145de044fd5cec4c9b8ed47360d98f.jpg"
        },
        { 
   
          "type": "cateid",
          "id": "4188",
          "name": "梵米派",
          "photo": "http://i.epetbar.com/nowater/cates/2015-07/28/45c339f6acb56364132b92f04b090c5c.jpg"
        }
      ]
    }
  ],
  "topadv": { 
   
    "advid": "20605",
    "src": "https://img2.epetbar.com/nowater/2017-04/05/14/19427a29344bcc0f385ca4718adca02f.jpg",
    "title": "红脚丫",
    "param": { 
   
      "mode": "web",
      "param": "http://sale.epet.com/m/mould/activity/ztMTAzOA%3D%3D.html?tid=1038"
    }
  },
  "owner": 53
}

解析如下:

注意:MyData类可以借助GsonFormat类生成实体类。

private List<MyData.CategorysBean.ChildrenBean> parseJSONOrgin(String string) { 
   
        List<MyData.CategorysBean.ChildrenBean> childrenBeanList = new ArrayList<MyData.CategorysBean.ChildrenBean>();

        try { 
   
            JSONObject jsonObject = new JSONObject(string);
            JSONArray jsonArray = jsonObject.getJSONArray("categorys");
            for (int i = 0; i < jsonArray.length(); i++) { 
   
                JSONObject jsonObject1 = jsonArray.getJSONObject(i);

                JSONArray children = jsonObject1.getJSONArray("children");
                for (int j = 0; j < children.length(); j++) { 
   
                    JSONObject jsonObject2 = children.getJSONObject(j);

                    MyData.CategorysBean.ChildrenBean childrenBean = new MyData.CategorysBean.ChildrenBean();
                    childrenBean.setName(jsonObject2.getString("name"));
                    childrenBean.setId(jsonObject2.getString("id"));
                    childrenBean.setPhoto(jsonObject2.getString("photo"));
                    childrenBean.setType(jsonObject2.getString("type"));
                    
                    childrenBeanList.add(childrenBean);
                }
            }

        } catch (JSONException e) { 
   
            e.printStackTrace();
        }


        return childrenBeanList;
    }

示例二:

[
  { 
   
    "id": 582490,
    "name": "单车自驾:魔幻张家界",
    "photos_count": 128,
    "start_date": "2016-04-05",
    "end_date": "2016-04-08",
    "days": 4,
    "level": 4,
    "views_count": 55199,
    "comments_count": 34,
    "likes_count": 441,
    "source": "web",
    "front_cover_photo_url": "http://p.chanyouji.cn/582490/1468260328216p1andi510ihgkc2f5hk6rf198.jpg",
    "featured": false,
    "user": { 
   
      "id": 313643,
      "name": "huchichi",
      "image": "http://tva2.sinaimg.cn/crop.0.12.282.282.50/5c5ee839gw1ec7kq4pasrj207v08d3zv.jpg"
    }
  },
  { 
   
    "id": 666746,
    "name": "【斯里兰卡10天】跨过山和大海",
    "photos_count": 122,
    "start_date": "2016-12-24",
    "end_date": "2017-01-02",
    "days": 10,
    "level": 3,
    "views_count": 33023,
    "comments_count": 32,
    "likes_count": 471,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/666746/1485787660939p1b7ntf07u16kdssn1tfl1ck1q1qd.jpg",
    "featured": false,
    "user": { 
   
      "id": 469471,
      "name": "宇_RainyK",
      "image": "http://a.chanyouji.cn/469471/1460020629.jpg"
    }
  },
  { 
   
    "id": 665223,
    "name": "上帝自留地探访 : 新西兰——快乐咔嚓声",
    "photos_count": 250,
    "start_date": "2016-11-30",
    "end_date": "2016-12-04",
    "days": 5,
    "level": 3,
    "views_count": 23981,
    "comments_count": 30,
    "likes_count": 533,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/1483013211/40p8jhlx7t4e8hntyhp4z31c0.jpg",
    "serial_id": 664971,
    "serial_position": 1,
    "featured": false,
    "user": { 
   
      "id": 131541,
      "name": "片儿川",
      "image": "http://a.chanyouji.cn/131541/1483887153821.jpg"
    }
  },
  { 
   
    "id": 591454,
    "name": "土耳其...我喜欢你,像风走了八千里",
    "photos_count": 195,
    "start_date": "2016-08-08",
    "end_date": "2016-08-22",
    "days": 15,
    "level": 3,
    "views_count": 18822,
    "comments_count": 42,
    "likes_count": 854,
    "source": "web",
    "front_cover_photo_url": "http://p.chanyouji.cn/1472368913/9896F012-522E-46C4-9F29-5F6D86C790DB.jpg",
    "featured": false,
    "user": { 
   
      "id": 208609,
      "name": "晶晶姑姑娘娘",
      "image": "http://a.chanyouji.cn/208609/1493099858.jpg"
    }
  },
  { 
   
    "id": 589708,
    "name": "浪迹非洲最南——“慢得啦”国闲游之一",
    "photos_count": 128,
    "start_date": "2016-07-23",
    "end_date": "2016-07-24",
    "days": 2,
    "level": 3,
    "views_count": 5858,
    "comments_count": 4,
    "likes_count": 65,
    "source": "web",
    "front_cover_photo_url": "http://p.chanyouji.cn/589708/1471963416200p1aqrtl1pq8js1ek0sn913uq1kdmh.jpg",
    "serial_id": 589708,
    "serial_position": 0,
    "featured": false,
    "user": { 
   
      "id": 103122,
      "name": "牵着蜗牛散步的JOY",
      "image": "http://tva1.sinaimg.cn/crop.0.17.640.640.50/794bd26ajw8e7tg9nfqb5j20hs0iqmxg.jpg"
    }
  },
  { 
   
    "id": 598966,
    "name": "霓虹国/留学生 梦游记录",
    "photos_count": 88,
    "start_date": "2016-08-28",
    "end_date": "2017-05-07",
    "days": 253,
    "level": 3,
    "views_count": 16648,
    "comments_count": 10,
    "likes_count": 72,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/1476365877/C9B59738-58E8-47C9-BCD1-5F2AC5CC9526.jpg",
    "featured": false,
    "user": { 
   
      "id": 694154,
      "name": "Y-dec",
      "image": "http://q.qlogo.cn/qqapp/100277927/5475C47B95A36891E2698462184F8785/100"
    }
  },
  { 
   
    "id": 544528,
    "name": "【我的年假】7 重庆—吃一顿地道火锅",
    "photos_count": 385,
    "start_date": "2016-08-31",
    "end_date": "2016-09-03",
    "days": 4,
    "level": 3,
    "views_count": 37214,
    "comments_count": 55,
    "likes_count": 530,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/544528/1474011393910p1asoupfpujrj1rnd5o813qo1jvi5.jpg",
    "serial_id": 544528,
    "serial_position": 0,
    "featured": false,
    "user": { 
   
      "id": 17010,
      "name": "马兰头头2010",
      "image": "http://a.chanyouji.cn/17010/1426768814.jpg"
    }
  },
  { 
   
    "id": 665311,
    "name": "就该这么玩【北海道】",
    "photos_count": 118,
    "start_date": "2016-12-05",
    "end_date": "2016-12-12",
    "days": 8,
    "level": 3,
    "views_count": 24644,
    "comments_count": 6,
    "likes_count": 108,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/1484295471/E2B2C32A-C910-490F-9F13-BC9D3B118C1B.jpg",
    "featured": false,
    "user": { 
   
      "id": 544219,
      "name": "炘仔~",
      "image": "http://a.chanyouji.cn/544219/1489641072.jpg"
    }
  },
  { 
   
    "id": 668998,
    "name": "漫步成都一一我的寻(熊)猫之旅",
    "photos_count": 108,
    "start_date": "2017-02-06",
    "end_date": "2017-02-12",
    "days": 7,
    "level": 3,
    "views_count": 15222,
    "comments_count": 30,
    "likes_count": 146,
    "source": "app",
    "front_cover_photo_url": "http://p.chanyouji.cn/1487129075/720F81CB-EE64-4681-8564-A9A6864AAD33.jpg",
    "featured": false,
    "user": { 
   
      "id": 261578,
      "name": "小柠12345",
      "image": "http://tva1.sinaimg.cn/crop.27.0.238.238.50/bb9ff9e8gw1eggbljiopfj208w06oaam.jpg"
    }
  },
  { 
   
    "id": 297060,
    "name": "「吃遍日本」大阪·神户·名古屋",
    "photos_count": 125,
    "start_date": "2015-04-25",
    "end_date": "2015-05-02",
    "days": 8,
    "level": 4,
    "views_count": 56384,
    "comments_count": 121,
    "likes_count": 948,
    "source": "web",
    "front_cover_photo_url": "http://p.chanyouji.cn/297060/1440912374444p19tuh3ukup7t1l5c1j0u8r6kfs2.jpg",
    "featured": false,
    "user": { 
   
      "id": 312316,
      "name": "CaitlinGao",
      "image": "http://tva3.sinaimg.cn/crop.0.0.640.640.50/96246e0bjw8ensjycmsdmj20hs0hsjs7.jpg"
    }
  }
]

解析如下:

注意:最外层是个方括号。


    private List<News> parseJSONOrgin(String json) { 
   
        List<News> list = new ArrayList<News>();
        try { 
   
            JSONArray jsonArray = new JSONArray(json);
            for (int i = 0; i < jsonArray.length(); i++) { 
   
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                News news = new News();
                news.setSource(jsonObject.getString("source"));
                news.setFront_cover_photo_url(jsonObject.getString("front_cover_photo_url"));
                news.setName(jsonObject.getString("name"));
                news.setStart_date(jsonObject.getString("start_date"));
                list.add(news);
            }
        } catch (JSONException e) { 
   
            e.printStackTrace();
        }
        return list;
    }

JSONObject获取Float Double类型数据的准确性:

示例:

{ 
   
    "status":0,
    "result":[
        { 
   
            "x":114.2307489832,
            "y":29.579081808346
        }
    ]
}

解析如下:

String jsonStr = "{\"status\":0,\"result\":[{\"x\":114.2307489832,\"y\":29.579081808346}]}";
try { 
   
    JSONObject jsonObject = new JSONObject(jsonStr);
    if (jsonObject.has("result")) { 
   
        JSONArray jsonArray = jsonObject.getJSONArray("result");
        for (int i = 0; i < jsonArray.length(); i++) { 
   
            JSONObject jsonObjectResult = jsonArray.getJSONObject(i);
            if (jsonObjectResult.has("x")) { 
   
                //方法一:
                String x = jsonObjectResult.getString("x");
                System.out.println("x============" + x);//114.2307489832
                Double aDouble = Double.valueOf(x);
                System.out.println("aDouble=======" + aDouble);//114.2307489832

                //方法二:
                String x1 = jsonObjectResult.get("x").toString();
                System.out.println("x1============" + x1);//114.2307489832
                Double aDouble1 = Double.valueOf(x1);
                System.out.println("aDouble1=======" + aDouble1);//114.2307489832

                //方法三
                double x2 = jsonObjectResult.getDouble("x");
                System.out.println("x2============" + x2);//114.2307489832

                //获取失败
                long x3 = jsonObjectResult.getLong("x");
                System.out.println("x3============" + x3);//114

            }
        }
    }
} catch (JSONException e) { 
   
    e.printStackTrace();
}

判断字符串是JSONObject还是JSONArray

使用 JSONTokener。JSONTokener.nextValue() 会给出一个对象,然后可以动态的转换为适当的类型。

示例一:

有时候这样:

{ 
   
    "id":"1",
    "courseID":"化学",
    "title":"滴定实验",
    "content":"下周二实验楼201必须完成"
}

有时候又这样:

[
    { 
   
        "id":"1",
        "courseID":"数学",
        "title":"一加一等于几"
    },
    { 
   
        "id":"2",
        "courseID":"语文",
        "title":"请背诵全文"
    }
]

解析如下:

//String jsonStr = "{\"id\":\"1\",\"courseID\":\"化学\",\"title\":\"滴定实验\",\"content\":\"下周二实验楼201必须完成\"}";
String jsonStr = "[{\"id\":\"1\",\"courseID\":\"数学\",\"title\":\"一加一等于几\"},{\"id\":\"2\",\"courseID\":\"语文\",\"title\":\"请背诵全文\"}]";

try { 
   
    Object object = new JSONTokener(jsonStr).nextValue();
    if (object instanceof JSONObject) { 
   
        System.out.println("==我是JSONObject==");
        JSONObject jsonObject = (JSONObject) object;

        if (jsonObject.has("title")) { 
   
            String title = jsonObject.getString("title");
            if (!TextUtils.isEmpty(title)) { 
   
                System.out.println("title==" + title);
            }
        }
    } else if (object instanceof JSONArray) { 
   
        System.out.println("==我是JSONArray==");
        JSONArray jsonArray = (JSONArray) object;

        for (int i = 0; i < jsonArray.length(); i++) { 
   
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            if (jsonObject.has("title")) { 
   
                String title = jsonObject.getString("title");
                if (!TextUtils.isEmpty(title)) { 
   
                    System.out.println("title==" + title);
                }
            }
        }
    }
} catch (JSONException e) { 
   
    e.printStackTrace();
}

示例二:

有时候这样:

{ 
   
    "cource":{ 
   
        "id":"1",
        "courseID":"数学",
        "title":"一加一等于几"
    }
}

有时候又这样:

{ 
   
    "cource":[
        { 
   
            "id":"1",
            "courseID":"数学",
            "title":"一加一等于几"
        },
        { 
   
            "id":"2",
            "courseID":"语文",
            "title":"请背诵全文"
        }
    ]
}

解析如下:

String jsonStr="{\"cource\":[{\"id\":\"1\",\"courseID\":\"数学\",\"title\":\"一加一等于几\"},{\"id\":\"2\",\"courseID\":\"语文\",\"title\":\"请背诵全文\"}]}";
//String jsonStr = "{\"cource\":{\"id\":\"1\",\"courseID\":\"数学\",\"title\":\"一加一等于几\"}}";

try { 
   
    JSONObject jsonObject = new JSONObject(jsonStr);

    if (jsonObject.has("cource")) { 
   
        String cource = jsonObject.getString("cource");
        Object object = new JSONTokener(cource).nextValue();
        if (object instanceof JSONArray) { 
   
            JSONArray jsonArray = (JSONArray) object;
            for (int k = 0; k < jsonArray.length(); k++) { 
   
                JSONObject parameterObject = jsonArray.getJSONObject(k);
                System.out.println("==我是JSONArray==" + parameterObject);
            }
        } else if (object instanceof JSONObject) { 
   
            JSONObject jsonObject1 = (JSONObject) object;
            System.out.println("==我是JSONObject==" + jsonObject1);
        }
    }

} catch (JSONException e) { 
   
    e.printStackTrace();
}

opt与get的区别:

get()取值不正确会抛出异常,必须用try catch或者throw包起

而opt()取值不正确则会试图进行转化或者输出友好值,不会抛出异常

json中的opt和get方法

get()和opt()
getBoolean()和optBoolean();
getDouble()和optDouble();
getInt()和optInt();
getLong()和optLong();
getString()和optString();
getJSONObject和optJSONobject();
getJSONArray和optJSONArray();

getJSONArray和optJSONArray()源码对比:

/** * Returns the value mapped by {@code name} if it exists and is a {@code * JSONArray}, or throws otherwise. * * @throws JSONException if the mapping doesn't exist or is not a {@code * JSONArray}. 不存在或不是jsonArray抛出异常 */
public JSONArray getJSONArray(String name) throws JSONException { 
   
	Object object = get(name);
	if (object instanceof JSONArray) { 
   
		return (JSONArray) object;
	} else { 
   
		throw JSON.typeMismatch(name, object, "JSONArray");
	}
}

/** * Returns the value mapped by {@code name} if it exists and is a {@code * JSONArray}, or null otherwise. 不存在或不是jsonArray返回null */
public JSONArray optJSONArray(String name) { 
   
	Object object = opt(name);
	return object instanceof JSONArray ? (JSONArray) object : null;
}

getString 可以看出 返回的任何数据类型都会被转换为String

public String getString(String name) throws JSONException { 
   
	Object object = get(name);
	String result = JSON.toString(object);
	if (result == null) { 
   
		throw JSON.typeMismatch(name, object, "String");
	}
	return result;
}

json的创建:

通过put方法来设置json的创建。

try { 
   
	createJson();
} catch (JSONException e) { 
   
	e.printStackTrace();
}

private String createJson() throws JSONException { 
   
	JSONObject jsonObject = new JSONObject();
	jsonObject.put("intKey", 123);
	jsonObject.put("doubleKey", 10.1);
	jsonObject.put("longKey", 666666666);
	jsonObject.put("stringKey", "lalala");
	jsonObject.put("booleanKey", true);

	JSONArray jsonArray = new JSONArray();
	jsonArray.put(0, 111);
	jsonArray.put("second");
	jsonObject.put("arrayKey", jsonArray);

	JSONObject innerJsonObject = new JSONObject();
	innerJsonObject.put("innerStr", "inner");
	jsonObject.put("innerObjectKey", innerJsonObject);

	System.out.println("创建的json=======" + jsonObject.toString());

	return jsonObject.toString();
}

打印结果:

{ 
   
    "intKey":123,
    "doubleKey":10.1,
    "longKey":666666666,
    "stringKey":"lalala",
    "booleanKey":true,
    "arrayKey":[
        111,
        "second"
    ],
    "innerObjectKey":{ 
   
        "innerStr":"inner"
    }
}

遍历key和value:

示例一:jsonobject

{ 
   
    "id":"1",
    "courseID":"化学",
    "title":"滴定实验",
    "content":"下周二实验楼201必须完成"
}
String jsonStr = "{\"id\":\"1\",\"courseID\":\"化学\",\"title\":\"滴定实验\",\"content\":\"下周二实验楼201必须完成\"}";

try { 
   
       JSONObject jsonObject = new JSONObject(jsonStr);

       Iterator iterator = jsonObject.keys();
       while (iterator.hasNext()) { 
   
           String key = (String) iterator.next();
           String value = jsonObject.getString(key);
           System.out.println(key + "===" + value);
       }

   } catch (JSONException e) { 
   
       e.printStackTrace();
   }

示例二:jsonarray

[
    { 
   
        "id":"1",
        "courseID":"数学",
        "title":"一加一等于几"
    },
    { 
   
        "id":"2",
        "courseID":"语文",
        "title":"请背诵全文"
    }
]
String jsonStr = "[{\"id\":\"1\",\"courseID\":\"数学\",\"title\":\"一加一等于几\"},{\"id\":\"2\",\"courseID\":\"语文\",\"title\":\"请背诵全文\"}]";
try { 
   
      JSONArray jsonArray = new JSONArray(jsonStr);
      if (jsonArray.length() > 0) { 
   
          for (int i = 0; i < jsonArray.length(); i++) { 
   
              JSONObject jsonObject = jsonArray.getJSONObject(i);

              Iterator iterator = jsonObject.keys();
              while (iterator.hasNext()) { 
   
                  String key = (String) iterator.next();
                  String value = jsonObject.getString(key);
                  System.out.println(key + "===" + value);
              }
          }
      }
  } catch (JSONException e) { 
   
      e.printStackTrace();
  }

今天的文章Android-json解析(三):原生JSONObject+JSONArray的解析、遍历及生成等分享到此就结束了,感谢您的阅读。

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