在这个应用程序中，我计划将json解析为碎片，当'is_broken'为真时，它只显示在第一个片段上，'is_repaired'为真，它只会显示在第二个片段上，也会显示'is_ok' 。在这个json中有一个有子的数据，它将在同一个列表中调用，但json的键也有相同的键，即'name'
我正在尝试解析这个json
{
"data": [
{
"name": "Table",
"is_broken": false,
"is_repaired": false,
"is_ok": true,
"asset_parent": {
"name": "2nd Floor",
"is_broken": false,
"is_repaired": false,
"is_ok": true,
"asset_parent": {
"name": "Grubi Building",
"is_broken": false,
"is_repaired": false,
"is_ok": true
}
}
},
{
"name": "4th Floor",
"is_broken": true,
"is_repaired": false,
"is_ok": false,
"asset_parent": {
"name": "Buni Building",
"is_broken": true,
"is_repaired": false,
"is_ok": false
}
}
]
}
我正在尝试解析数据，但只是将其放入listview中的父级名称。这个数据上有一个孩子，我试图在这个片段代码上把它称为它的父元素
public static String in_aset = "aset";
public static String in_gedung = "rektorat";
public static String in_ruang = "000";
ProgressDialog pDialog;
JSONArray str_json = null;
ListView list, list2;
AssetsAdapter adapter;
ArrayList<HashMap<String, String>> data_map = new ArrayList<HashMap<String, String>>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_baik, container, false);
new daftarAset().execute();
return view;
}
class daftarAset extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String... params) {
String link_url = "https://example.com/api/assets";
JSONParser jParser = new JSONParser();
JSONObject json = jParser.AmbilJson(link_url);
try {
str_json = json.getJSONArray("data");
for (int i = 0; i < str_json.length(); i++) {
JSONObject ar = str_json.getJSONObject(i);
String aset = ar.getString("name").trim();
HashMap map = new HashMap();
map.put(in_aset, aset);
data_map.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
list = (ListView) getView().findViewById(R.id.baik_list);
adapter = new AssetsAdapter(getActivity(), data_map);
list.setAdapter(adapter);
setListViewHeightBasedOnChildren(list);
}
});
return null;
}
@Override
protected void onPostExecute(String s) {
pDialog.dismiss();
}
}
public static void setListViewHeightBasedOnChildren(ListView listView) {
ListAdapter listAdapter = listView.getAdapter();
if (listAdapter == null) return;
int desiredWidth = View.MeasureSpec.makeMeasureSpec(listView.getWidth(), View.MeasureSpec.UNSPECIFIED);
int totalHeight = 0;
View view = null;
for (int i = 0; i < listAdapter.getCount(); i++) {
view = listAdapter.getView(i, view, listView);
if (i == 0)
view.setLayoutParams(new ViewGroup.LayoutParams(desiredWidth, ViewGroup.LayoutParams.WRAP_CONTENT));
view.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);
totalHeight += view.getMeasuredHeight();
}
ViewGroup.LayoutParams params = listView.getLayoutParams();
params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
listView.setLayoutParams(params);
listView.requestLayout();
}
and this is the adapter of code above
public class AssetsAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater = null;
public AssetsAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
activity = a;
data = d;
inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View vi = convertView;
if (convertView == null) vi = inflater.inflate(R.layout.list_chart, null);
TextView textCucu = (TextView) vi.findViewById(R.id.aset1);
TextView textAnak = (TextView) vi.findViewById(R.id.lokasi);
TextView textBapak = (TextView) vi.findViewById(R.id.waktu);
HashMap<String, String> getdata = new HashMap<String, String>();
getdata = data.get(position);
textCucu.setText(getdata.get(BaikFragment.in_aset));
textAnak.setText(getdata.get(BaikFragment.in_ruang));
return vi;
}
}
TextView textCucu，textAnak，textBapak与listview相反，带有键'name'的json必须使用具有子节点的json的相同listview输入。 但当我尝试上面的代码时，我得到了这个错误消息
E/JSON Parser: Error parsing data org.json.JSONException: Value <!DOCTYPE of type java.lang.String cannot be converted to JSONObject
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #2
Process: com.mqa.android.monas, PID: 30517
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:304)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'org.json.JSONArray org.json.JSONObject.getJSONArray(java.lang.String)' on a null object reference
at com.mqa.android.monas.Fragment.BaikFragment$daftarAset.doInBackground(BaikFragment.java:174)
at com.mqa.android.monas.Fragment.BaikFragment$daftarAset.doInBackground(BaikFragment.java:157)
at android.os.AsyncTask$2.call(AsyncTask.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
D/EGL_emulation: eglMakeCurrent: 0xb438b280: ver 2 0
E/WindowManager: android.view.WindowLeaked: Activity com.mqa.android.monas.Activity.AsetActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{dccaffa V.E..... R......D 0,0-1026,304} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:363)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:271)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85)
at android.app.Dialog.show(Dialog.java:298)
at com.mqa.android.monas.Fragment.BaikFragment$daftarAset.onPreExecute(BaikFragment.java:165)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:591)
at android.os.AsyncTask.execute(AsyncTask.java:539)
at com.mqa.android.monas.Fragment.BaikFragment.onCreateView(BaikFragment.java:96)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2354)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1419)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1809)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:799)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2199)
at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:651)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:145)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1236)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1084)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1614)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:714)
at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:91)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1361)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:784)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
at android.view.View.measure(View.java:17547)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015)
at android.view.ViewRootImpl.measureHierarchy(View
请帮忙。我如何使用相同的json键解析具有相同列表视图中的子项的json数据。或者我应该编写什么代码来解析json到列表中
答案 0 :(得分：1)
您正在NullPointerException行
str_json = json.getJSONArray("data");
调试并检查为什么将json作为null，在解析之前保持空检查
try {
if(json!=null){
str_json = json.getJSONArray("data");
for (int i = 0; i < str_json.length(); i++) {
JSONObject ar = str_json.getJSONObject(i);
String aset = ar.getString("name").trim();
HashMap map = new HashMap();
map.put(in_aset, aset);
data_map.add(map);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
或抓住Exception代替JSONException（不推荐）
答案 1 :(得分：-1)
请不要再以这种方式解析json。
Google已经部署了一个令人难以置信的库来以一种强大而简单的方式解析json。 只是：
Gson gson = new GsonBuilder()
gson.fromJson(jsonString)
有关如何设置此库的更多信息，请参阅教程的链接：http://borntocode.fr/android-mettre-en-place-et-utiliser-gson-pour-faciliter-lutilisation-du-json/