Json 解析错误:类型 org.json.JSONArray 无法转换为 JSONObject

Question

JSON很简单，

[{"kw"："48.90"，"kva"："51.20"，"pf"："-0.96"}]

我得到的错误是，

08-26

02：28：49.130 13605-13641/com.whatever.emshive E/MainActivity： 来自网址的响应： [{"kw"："48.90"，"kva"："51.20"，"pf"："-0.96"}] Json 解析错误：值 [{"kw"："48.90"，"kva"："51.20"，"pf"："-0.96"}] 类型为 org.json.JSONArray 无法转换为 JSONObject 08-26 02：28：49.130 13605-13641/com.whatever.emshive E/JSON 解析器：解析数据时出错 org.json.JSONException： Value [{"kw"："48.90"，"kva"："51.20"，"pf"："-0.96"}] 的类型 org.json.JSONArray 无法转换为 JSONObject

代码是，

public class MainActivity extends AppCompatActivity {
private String TAG = MainActivity.class.getSimpleName();
private ProgressDialog pDialog;
private ListView lv;
// URL to get contacts JSON
private static String url = "http://simpleasthat.com/s.php";
ArrayList<HashMap<String, String>> contactList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
contactList = new ArrayList<>();
lv = (ListView) findViewById(R.id.list);
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
JSONArray contacts = jsonObj.getJSONArray("contacts");
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(0);
String kw = c.getString("kw");
String kva = c.getString("kva");
String pf = c.getString("pf");
// tmp hash map for single contact
HashMap<String, String> contact = new HashMap<>();
// adding each child node to HashMap key => value
contact.put("kw", kw);
contact.put("kva", kva);
contact.put("pf", pf);
// adding contact to contact list
contactList.add(contact);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
Log.e("JSON Parser", "Error parsing data " + e.toString());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG)
.show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG)
.show();
}
});
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, contactList,
R.layout.list_item, new String[]{"kw", "kva",
"pf"}, new int[]{R.id.kw,
R.id.kva, R.id.pf});
lv.setAdapter(adapter);
}
}

}

我尝试在StackOverflow中查看其他类似的答案，但无法得到。非常感谢帮助。谢谢

Answer 1

请将 GetContacts.doInBackground 中的代码从

JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
JSONArray contacts = jsonObj.getJSONArray("contacts");

自

JSONArray contacts = new JSONArray(jsonStr);

Answer 2

正如消息所述，您正在尝试将 JSON 数组转换为 JSON 对象。您的 JSON 是一个数组...