Question

我在开发Android应用程序时遇到了这个熟悉的异常

消息没有值

我确信我的JSONObject包含了我正在寻找的内容：

这是我的JSON对象，您可以对其进行格式化以便更好地理解它：http://jsonformatter.curiousconcept.com/

    {
  "data": [
    {
      "id": "1438734076389483_1440132306249660", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "14387376389483"
      }, 
      "message": "TEST TEST", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/14387340769483/posts/14401323069660"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/14387376389483/posts/14402306249660"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T18:49:43+0000", 
      "updated_time": "2014-07-14T18:49:43+0000", 
      "likes": {
        "data": [
          {
            "id": "84207420", 
            "name": "Akira Yuki"
          }, 
          {
            "id": "14387346389483", 
            "name": "AKA"
          }
        ], 
        "paging": {
          "cursors": {
            "after": "MTQzODczNDA3NjM4OTQ4Mw==", 
            "before": "ODQyMDQ3NDIw"
          }
        }
      }
    }, 
    {
      "id": "1438734076389483_14399988596342", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "1438734076389483"
      }, 
      "message": "MEssage test number twooooo", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/143873076389483/posts/143999881956342"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/143873076389483/posts/143999819596342"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T10:58:20+0000", 
      "updated_time": "2014-07-14T10:58:20+0000"
    }, 
    {
      "id": "143873476389483_1439998362929721", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "1438734076389483"
      }, 
      "message": "Never give up", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/143873406389483/posts/143999836292721"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/143873076389483/posts/139998362929721"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T10:55:16+0000", 
      "updated_time": "2014-07-14T10:55:16+0000"
    }, 
    {
      "id": "1438734076389483_1439998316263059", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "1438734076389483"
      }, 
      "message": "lemme try", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/143873476389483/posts/143998316263059"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/143734076389483/posts/143998316263059"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T10:54:54+0000", 
      "updated_time": "2014-07-14T10:54:54+0000"
    }, 
    {
      "id": "143873407639483_1439990399597184", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "143873407389483"
      }, 
      "message": "AAAAAAAAAAAAAAA BBBBBBBBBBBBBBB", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/143734076389483/posts/143990399597184"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/143734076389483/posts/143999039957184"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T10:12:51+0000", 
      "updated_time": "2014-07-14T10:12:51+0000"
    }, 
    {
      "id": "143873407689483_143998952930603", 
      "from": {
        "category": "Community", 
        "name": "AKA", 
        "id": "1438734076389483"
      }, 
      "message": "hello", 
      "actions": [
        {
          "name": "Comment", 
          "link": "https://www.facebook.com/143734076389483/posts/14399895420603"
        }, 
        {
          "name": "Like", 
          "link": "https://www.facebook.com/143873407638483/posts/143989542930603"
        }
      ], 
      "privacy": {
        "description": "Public", 
        "value": "EVERYONE", 
        "friends": "", 
        "networks": "", 
        "allow": "", 
        "deny": ""
      }, 
      "type": "status", 
      "status_type": "mobile_status_update", 
      "created_time": "2014-07-14T10:05:09+0000", 
      "updated_time": "2014-07-14T10:05:09+0000"
    }
  ], 
  "paging": {
    "previous": "https://graph.facebook.com/v2.0/143873476389483/feed?limit=25&since=140363783", 
    "next": "https://graph.facebook.com/v2.0/143873406389483/feed?limit=25&until=140532308"
  }
}

这里是我的代码，因为它是例外

                            JSONObject oneRowJSONObj = response
                                    .getGraphObject()
                                    .getInnerJSONObject();

                            JSONArray dataJSONArray = oneRowJSONObj
                                    .getJSONArray("data");

                            Log.v(TAG, dataJSONArray.toString());

//Working

                            for (int i = 0; i < dataJSONArray.length() ; i++) {
                                JSONObject c = dataJSONArray
                                        .getJSONObject(i);

                                // Storing JSON item in a Variable
                                String message = c.getString("message");


                                Log.v("ONE ROW", message);//Here i get the exception

Answer 1

所以......你正在重复data部分中的项目：

for (int i = 0; i < dataJSONArray.length() ; i++) {
    JSONObject c = dataJSONArray.getJSONObject(i);

但是假设您在该数组中获得的每个项目都是＆＃34;消息＆＃34;之一：

String message = c.getString("message");

但不幸的是，它并不仅仅包含它。该数组将包含data子节中的所有键，包括：id，from，message，actions，privacy等。

因此，您可能（但不能保证）您的第一次迭代会获得只有密钥＆＃34; id＆＃34;的JSONObject。由于您未进行任何检查以查看c是否有＆＃34;消息＆＃34;价值（它没有），你得到了例外。如果密钥不存在，则无法致电getString()。您可以执行if (c.has("message")，也可以致电optString()为其提供可选参数。

JSONObject异常：消息没有值

1 个答案: