如何解析对象内的 2 个 JSON 数组

Question

我正在尝试使用以下信息解析 JSON，如您所见，它提供了一个 JSON 对象，该对象具有一个值，然后是一个 JSON 数组，如果排除了 JSON 对象（结果：1），我可以解析以下内容，但是当我尝试下面的代码并按下按钮以检索数据时，它没有提供任何数据。

url 看起来和这个类似，但是有很多数据：

{  
"result":1,
"data":[  
{  
"id":"1",
"langtitude":"31.3256632",
"latitude":"20.3256632",
"userNumber":"23",
"address":"adfsf",
"userFK":"1"
},
{  
"id":"2",
"langtitude":"31.3256632",
"latitude":"20.3256632",
"userNumber":"23",
"address":"adfsf",
"userFK":"1"
}
]
}

MainActivity.Java

public class MainActivity extends AppCompatActivity {

private TextView tv_json;
private ProgressDialog progressDialog;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

tv_json = (TextView)findViewById(R.id.tv_json);

Button btn_parsJSON = (Button)findViewById(R.id.btn_parsJSON);

btn_parsJSON.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
new JSONTask().execute("I put the URL here");
}
});

}
public class JSONTask extends AsyncTask<String, String, String>{

@Override
protected void onPreExecute() {
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setTitle("Please wait ...");
progressDialog.setMessage("Grabbing Data");
progressDialog.setCancelable(false);
progressDialog.show();

super.onPreExecute();
}

@Override
protected String doInBackground(String... urls) {
{
HttpURLConnection connection = null;
BufferedReader reader = null;

try {
URL url = new URL(urls[0]);
connection = (HttpURLConnection)url.openConnection();
connection.connect();

InputStream stream = connection.getInputStream();

reader = new BufferedReader(new InputStreamReader(stream));

StringBuffer buffer = new StringBuffer();


String line = "";

while((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();

JSONObject parentObject = new JSONObject(finalJson);
JSONObject array = parentObject.getJSONObject("result");
JSONArray parentArray = array.getJSONArray("data");


StringBuffer finalBuffer = new StringBuffer();
for (int i = 0; i < parentArray.length(); i++) {


JSONObject finalObject = parentArray.getJSONObject(i);

double langtitude = finalObject.getDouble("langtitude");
double latitude = finalObject.getDouble("latitude");
int userNumber = finalObject.getInt("userNumber");
String address = finalObject.getString("address");
int userFK = finalObject.getInt("userFK");

finalBuffer.append(langtitude + "\n" + latitude + "\n" + userNumber + "\n" 
+ address + "\n" + userFK + "\n\n");
                }
return finalBuffer.toString();


} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
}
try {
if(reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}

@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
tv_json.setText(result);
progressDialog.dismiss();

}
}

}

Answer 1

当你这样做时

JSONObject parentObject = new JSONObject(finalJson);
JSONObject array = parentObject.getJSONObject("result");
JSONArray parentArray = array.getJSONArray("data");

您正在 result 块内寻找 data。你不会在那里找到它。我认为你应该这样做：

JSONArray parentArray = parentObject.getJSONArray("data");

**编辑：**刚刚尝试过

String finalJson = "{  \n" +
        "\"result\":1,\n" +
        "\"data\":[  \n" +
        "{  \n" +
        "\"id\":\"1\",\n" +
        "\"langtitude\":\"31.3256632\",\n" +
        "\"latitude\":\"20.3256632\",\n" +
        "\"userNumber\":\"23\",\n" +
        "\"address\":\"adfsf\",\n" +
        "\"userFK\":\"1\"\n" +
        "},\n" +
        "{  \n" +
        "\"id\":\"2\",\n" +
        "\"langtitude\":\"31.3256632\",\n" +
        "\"latitude\":\"20.3256632\",\n" +
        "\"userNumber\":\"23\",\n" +
        "\"address\":\"adfsf\",\n" +
        "\"userFK\":\"1\"\n" +
        "}\n" +
        "]\n" +
        "}";

try {
    JSONObject reader = new JSONObject(finalJson);
    int result  = reader.getInt("result");
    JSONArray data  = reader.getJSONArray("data");

    Log.i("MYTAG", "reader:" + reader);
    Log.i("MYTAG", "result: "+result);
    Log.i("MYTAG", "data: "+data);

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

日志：

阅读器：{"result":1,"data":[{"id":"1","langtitude":"31.3256632","latitude":"20.3256632","userNumber":"23", "地址":"adfsf","userFK":"1"},{"id":"2","langtitude":"31.3256632","纬度":"20.3256632","userNumber":"23", "地址":"adfsf","userFK":"1"}]}

结果：1​​

数据：[{"id":"1","langtitude":"31.3256632","latitude":"20.3256632","userNumber":"23","address":"adfsf","userFK" :"1"},{"id":"2","langtitude":"31.3256632","latitude":"20.3256632","userNumber":"23","address":"adfsf","userFK" :"1"}]

Answer 2

这可能会解决问题 - 请记住我没有尝试过，所以它可能包含拼写错误，但希望它会为您指明一个有用的方向：

String response = //your json;
JsonObject jsonObject = new JsonObject(response);
JsonArray jsonArray = jsonObject.getjsonArray("data");
for(int i=0; i<jsonArray.length(); i++) {
  JsonObject tobject = jsonArray.get(i);
}