得到没有数组名的 JSONArray?

我是 JSON 的新手,正在尝试这个教程: Http://p-xr.com/android-tutorial-how-to-parse-read-json-data-into-a-android-listview/#comments

我对 JSON、 C 语言、 Java 和 Android 都是新手,但我正在学习。本教程使用我称之为命名数组的东西,但是我将在 android 项目中使用的所有 JSON 都将使用没有命名数组的简单表行。我正在使用的 JSON 和本教程中的地震 JSON 的示例如下。

本教程迭代地震数组,并使用以下代码将其转换为 JAVA 散列表:

JSONArray  earthquakes = json.getJSONArray("earthquakes");
for(int i=0;i<earthquakes.length();i++){
HashMap<String, String> map = new HashMap<String, String>();
JSONObject e = earthquakes.getJSONObject(i);


map.put("id",  String.valueOf(i));
map.put("name", "Earthquake name:" + e.getString("eqid"));
map.put("magnitude", "Magnitude: " +  e.getString("magnitude"));
mylist.add(map);
}

我的问题是,如果我的 JSON 如下所示简单,我如何使用 json.getJSONArray("")?我可以转换其余的代码,我只需要知道如何加载该 JSON 使用的 getJSONArray("strJsonArrayName"),如果我没有一个 strJsonArrayName

我的 JSON (未命名数组)

[
{
"cnt":1,
"name":"American",
"pk":7
},
{
"cnt":2,
"name":"Celebrities",
"pk":3
},
{
"cnt":1,
"name":"Female",
"pk":2
},
{
"cnt":1,
"name":"Language",
"pk":8
},
{
"cnt":1,
"name":"Male",
"pk":1
},
{
"cnt":1,
"name":"Region",
"pk":9
}
]

教程的 JSON (命名数组)

{
"earthquakes":[
{
"eqid":"c0001xgp",
"magnitude":8.8,
"lng":142.369,
"src":"us",
"datetime":"2011-03-11 04:46:23",
"depth":24.4,
"lat":38.322
},
{
"eqid":"c000905e",
"magnitude":8.6,
"lng":93.0632,
"src":"us",
"datetime":"2012-04-11 06:38:37",
"depth":22.9,
"lat":2.311
},
{
"eqid":"2007hear",
"magnitude":8.4,
"lng":101.3815,
"src":"us",
"datetime":"2007-09-12 09:10:26",
"depth":30,
"lat":-4.5172
},
{
"eqid":"c00090da",
"magnitude":8.2,
"lng":92.4522,
"src":"us",
"datetime":"2012-04-11 08:43:09",
"depth":16.4,
"lat":0.7731
},
{
"eqid":"2007aqbk",
"magnitude":8,
"lng":156.9567,
"src":"us",
"datetime":"2007-04-01 18:39:56",
"depth":10,
"lat":-8.4528
},
{
"eqid":"2007hec6",
"magnitude":7.8,
"lng":100.9638,
"src":"us",
"datetime":"2007-09-12 21:49:01",
"depth":10,
"lat":-2.5265
},
{
"eqid":"a00043nx",
"magnitude":7.7,
"lng":100.1139,
"src":"us",
"datetime":"2010-10-25 12:42:22",
"depth":20.6,
"lat":-3.4841
},
{
"eqid":"2010utc5",
"magnitude":7.7,
"lng":97.1315,
"src":"us",
"datetime":"2010-04-06 20:15:02",
"depth":31,
"lat":2.3602
},
{
"eqid":"2009mebz",
"magnitude":7.6,
"lng":99.9606,
"src":"us",
"datetime":"2009-09-30 08:16:09",
"depth":80,
"lat":-0.7889
},
{
"eqid":"2009kdb2",
"magnitude":7.6,
"lng":92.9226,
"src":"us",
"datetime":"2009-08-10 17:55:39",
"depth":33.1,
"lat":14.0129
}
]
}

在本教程中,基于@M Γ LL 和@Cody Caughlan 的答案,我能够将 JSONFunctions.getJSONFromURL 重新格式化为 JSONArray 而不是 JSONObject。这是我修改后的工作代码,谢谢!

public class JSONfunctions {
public static JSONArray getJSONfromURL(String url){
InputStream is = null;
String result = "";
JSONArray jArray = null;


HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();


BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();


jArray = new JSONArray(result);
return jArray;
}
}
130713 次浏览

JSONArray有一个构造函数,它接受一个 String源(假定为一个数组)。

就像这样

JSONArray array = new JSONArray(yourJSONArrayAsString);

您根本不需要调用 json.getJSONArray(),因为您正在使用的 JSON 已经是一个数组 。因此,不要构造 JSONObject的实例; 使用 JSONArray。这应该足够了:

// ...
JSONArray json = new JSONArray(result);
// ...


for(int i=0;i<json.length();i++){
HashMap<String, String> map = new HashMap<String, String>();
JSONObject e = json.getJSONObject(i);


map.put("id",  String.valueOf(i));
map.put("name", "Earthquake name:" + e.getString("eqid"));
map.put("magnitude", "Magnitude: " +  e.getString("magnitude"));
mylist.add(map);
}

您不能使用与本教程中完全相同的方法,因为您正在处理的 JSON 需要从根目录解析为 JSONArray,而不是 JSONObject

我假设一个命名的 JSONArray 是一个 JSONObject,并从服务器访问数据以填充一个 Android GridView。值得一提的是,我的方法是:

private String[] fillTable( JSONObject jsonObject ) {
String[] dummyData = new String[] {"1", "2", "3", "4", "5", "6", "7","1", "2", "3", "4", "5", "6", "7","1", "2", "3", "4", "5", "6", "7", };
if( jsonObject != null ) {
ArrayList<String> data = new ArrayList<String>();
try {
// jsonArray looks like { "everything" : [{}, {},] }
JSONArray jsonArray = jsonObject.getJSONArray( "everything" );
int number = jsonArray.length(); //How many rows have got from the database?
Log.i( Constants.INFORMATION, "Number of ows returned:  " + Integer.toString( number ) );
// Array elements look like this
//{"success":1,"error":0,"name":"English One","owner":"Tutor","description":"Initial Alert","posted":"2013-08-09 15:35:40"}
for( int element = 0; element < number; element++ ) { //visit each element
JSONObject jsonObject_local = jsonArray.getJSONObject( element );
//  Overkill on the error/success checking
Log.e("JSON SUCCESS", Integer.toString( jsonObject_local.getInt(Constants.KEY_SUCCESS) ) );
Log.e("JSON ERROR", Integer.toString( jsonObject_local.getInt(Constants.KEY_ERROR) ) );
if ( jsonObject_local.getInt( Constants.KEY_SUCCESS) == Constants.JSON_SUCCESS ) {
String name = jsonObject_local.getString( Constants.KEY_NAME );
data.add( name );
String owner = jsonObject_local.getString( Constants.KEY_OWNER );
data.add( owner );
String description = jsonObject_local.getString( Constants.KEY_DESCRIPTION );
Log.i( "DESCRIPTION", description );
data.add( description );
String date = jsonObject_local.getString( Constants.KEY_DATE );
data.add( date );
}
else {
for( int i = 0; i < 4; i++ ) {
data.add( "ERROR" );
}
}
}
}  //JSON object is null
catch ( JSONException jsone) {
Log.e( "JSON EXCEPTION", jsone.getMessage() );
}
dummyData = data.toArray( dummyData );
}
return dummyData;

}

下面是19API lvl 下的一个解决方案:

  • 首先,做一个 Gson obj。—— > Gson gson = new Gson();

  • 第二步是使用 StringRequest (而不是 JsonObjectRequest)

  • 得到 JsonArray 的最后一步..。

YoursObjArray[] yoursObjArray = gson.fromJson(response, YoursObjArray[].class);