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更新时间：2023-11-16 13:41:28
由于你的web服务返回一个 JSONArray 而不是的JSONObject 但你正试图将其转换为JSONObject的。改变，而不是的JSONObject 的 getJSONFromUrl 方法的返回类型为 JSONArray 如：
公共JSONArray getJSONFromUrl（字符串URL）{
JSONArray jsonarr = NULL;
//使HTTP请求
//尝试解析字符串到JSONArray
尝试 {
jsonarr =新JSONArray（JSON）;
}赶上（JSONException E）{
}
//返回JSON字符串
返回jsonarr; //＆LT;＆LT;＆LT;＆LT;返回JSONArray代替的JSONObject
}
和呼叫 getJSONFromUrl 从活动中的onCreate：
JSONArray JSON = jParser.getJSONFromUrl（URL）;
尝试 {
//遍历所有联系人
的for（int i = 0; I＆LT; json.length（）;我++）{
JSONObject的C = json.getJSONObject（我）;
//把你分析code在这里
}
}赶上（JSONException E）{
e.printStackTrace（）;
}
I'm looking for a good tutorial to parse JSON into Listview in Android.
The problem is my JSON file is like this
[{"location_id":"823","company_id":"41","name":"Milj\u00f8station","address":"Aldersro \/ Aldersro 8","place":"","postal":"5700","city":"Svendborg","monday":"","tuesday":"","wednesday":"","thursday":"","friday":"","saturday":"","sunday":"","type":"2","lat":"55.061426149085","lng":"10.5927246809006","nocar":"0","distance":"0.00023254303859579"}]
Most tutorials starting with a Json array, and later the data. I know there is a lot of examples but i couldn't find some it that match my problem.
I added code, but still it's not working, here is my 3 classes.
SingleMenuItemActivity
public class SingleMenuItemActivity extends Activity {
// JSON node keys
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_PHONE_MOBILE = "mobile";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.single_list_item);
// getting intent data
Intent in = getIntent();
// Get JSON values from previous intent
String name = in.getStringExtra(TAG_NAME);
String cost = in.getStringExtra(TAG_EMAIL);
String description = in.getStringExtra(TAG_PHONE_MOBILE);
// Displaying all values on the screen
TextView lblName = (TextView) findViewById(R.id.name_label);
TextView lblCost = (TextView) findViewById(R.id.email_label);
TextView lblDesc = (TextView) findViewById(R.id.mobile_label);
lblName.setText(name);
lblCost.setText(cost);
lblDesc.setText(description);
} }
JSONParser
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
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();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
} }
AndroidJSONParserActvity
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://webservice.xxx.com/webservice/getLocationList.php?lat=55.061424255371094&lng=10.592724800109863";
// JSON Node names
private static final String TAG_Location = "location_id";
private static final String TAG_Company = "company_id";
private static final String TAG_NAME = "name";
private static final String TAG_ADDRESS = "address";
private static final String TAG_PLACE = "place";
private static final String TAG_POSTAL = "postal";
private static final String TAG_CITY = "city";
private static final String TAG_MONDAY = "monday";
private static final String TAG_TUESDAY = "tuesday";
private static final String TAG_WEDNESDAY = "wednesday";
private static final String TAG_THURSDAY = "thursday";
private static final String TAG_FRIDAY = "friday";
private static final String TAG_SATURDAY = "saturday";
private static final String TAG_SUNDAY = "sunday";
private static final String TAG_TYPE = "type";
private static final String TAG_LAT = "lat";
private static final String TAG_LNG = "lng";
private static final String TAG_NOCAR = "nocar";
// contacts JSONArray
JSONArray contacts = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String location_id = c.getString(TAG_Location);
String company_id = c.getString(TAG_Company);
String name = c.getString(TAG_NAME);
String address = c.getString(TAG_ADDRESS);
String place = c.getString(TAG_PLACE);
String postal = c.getString(TAG_POSTAL);
String city = c.getString(TAG_CITY);
String monday = c.getString(TAG_MONDAY);
String tuesday = c.getString(TAG_TUESDAY);
String wednesday = c.getString(TAG_WEDNESDAY);
String thursday = c.getString(TAG_THURSDAY);
String friday = c.getString(TAG_FRIDAY);
String saturday = c.getString(TAG_SATURDAY);
String sunday = c.getString(TAG_SUNDAY);
String type = c.getString(TAG_TYPE);
String lat = c.getString(TAG_LAT);
String lng = c.getString(TAG_LNG);
String nocar = c.getString(TAG_NOCAR);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_Location, location_id);
map.put(TAG_Company, company_id);
map.put(TAG_NAME, name);
map.put(TAG_ADDRESS, address);
map.put(TAG_PLACE, place);
map.put(TAG_POSTAL, postal);
map.put(TAG_CITY, city);
map.put(TAG_MONDAY, monday);
map.put(TAG_TUESDAY, tuesday);
map.put(TAG_WEDNESDAY, wednesday);
map.put(TAG_THURSDAY, thursday);
map.put(TAG_FRIDAY, friday);
map.put(TAG_SATURDAY, saturday);
map.put(TAG_SUNDAY, sunday);
map.put(TAG_TYPE, type);
map.put(TAG_LAT, lat);
map.put(TAG_LNG, lng);
map.put(TAG_NOCAR, nocar);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_LAT, TAG_Company }, new int[] {
R.id.name, R.id.email, R.id.mobile });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.email)).getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_Location, cost);
in.putExtra(TAG_Company, description);
startActivity(in);
}
});
} }
Error in Log Cat
02-06 10:06:19.025: D/AbsListView(9115): Get MotionRecognitionManager 02-06 10:06:19.705: D/dalvikvm(9115): GC_CONCURRENT freed 206K, 6% free 12315K/12999K, paused 13ms+14ms, total 40ms 02-06 10:06:19.725: E/JSON Parser(9115): Error parsing data org.json.JSONException: Value [{"nocar":"0","company_id":"41","postal":"5700","thursday":"","monday":"","lng":"10.5927246809006","type":"2","city":"Svendborg","location_id":"823","distance":"0.00023254303859579","wednesday":"","address":"Aldersro \/ Aldersro 8","sunday":"","name":"Miljøstation","saturday":"","friday":"","tuesday":"","place":"","lat":"55.061426149085"},
02-06 10:06:19.730: D/AndroidRuntime(9115): Shutting down VM
02-06 10:06:19.730: W/dalvikvm(9115): threadid=1: thread exiting with uncaught exception (group=0x4100f2a0)
02-06 10:06:19.740: E/AndroidRuntime(9115): FATAL EXCEPTION: main
02-06 10:06:19.740: E/AndroidRuntime(9115): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidhive.jsonparsing/com.androidhive.jsonparsing.AndroidJSONParsingActivity}: java.lang.NullPointerException
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2100)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2125)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread.access$600(ActivityThread.java:140)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1227)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.os.Handler.dispatchMessage(Handler.java:99)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.os.Looper.loop(Looper.java:137)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread.main(ActivityThread.java:4898)
02-06 10:06:19.740: E/AndroidRuntime(9115): at java.lang.reflect.Method.invokeNative(Native Method)
02-06 10:06:19.740: E/AndroidRuntime(9115): at java.lang.reflect.Method.invoke(Method.java:511)
02-06 10:06:19.740: E/AndroidRuntime(9115): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
02-06 10:06:19.740: E/AndroidRuntime(9115): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
02-06 10:06:19.740: E/AndroidRuntime(9115): at dalvik.system.NativeStart.main(Native Method)
02-06 10:06:19.740: E/AndroidRuntime(9115): Caused by: java.lang.NullPointerException
02-06 10:06:19.740: E/AndroidRuntime(9115): at com.androidhive.jsonparsing.AndroidJSONParsingActivity.onCreate(AndroidJSONParsingActivity.java:69)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.Activity.performCreate(Activity.java:5206)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1083)
02-06 10:06:19.740: E/AndroidRuntime(9115): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2064)
02-06 10:06:19.740: E/AndroidRuntime(9115): ... 11 more
because your webservice returning an JSONArray instead of JSONObject but you are trying to convert it to JSONObject . change your getJSONFromUrl method return type to JSONArray instead of JSONObject as :
public JSONArray getJSONFromUrl(String url) {
JSONArray jsonarr=null;
// Making HTTP request
// try parse the string to a JSONArray
try {
jsonarr = new JSONArray(json);
} catch (JSONException e) {
}
// return JSON String
return jsonarr; //<<<< return JSONArray instead of JSONObject
}
and call getJSONFromUrl as from onCreate of Activity :
JSONArray json = jParser.getJSONFromUrl(url);
try {
// looping through All Contacts
for(int i = 0; i < json.length(); i++){
JSONObject c = json.getJSONObject(i);
// put your parsing code here
}
} catch (JSONException e) {
e.printStackTrace();
}