我有一个活动＆＃34; HomeActivity＆＃34;其中有一个片段，其中一个是＃34; PeopleMEFragment＆＃34;。 当我点击＆＃34; People＆＃34;选项卡/文本，我每次启动应用程序时都会得到以下错误，然后随机：
Attempt to invoke virtual method 'com.google.gson.JsonObject com.google.gson.JsonElement.getAsJsonObject()' on a null object reference
at com.pubnub.api.managers.MapperManager.elementToInt(MapperManager.java:94)
at com.pubnub.api.endpoints.presence.HereNow.parseMultipleChannelResponse(HereNow.java:136)
at com.pubnub.api.endpoints.presence.HereNow.createResponse(HereNow.java:105)
at com.pubnub.api.endpoints.presence.HereNow.createResponse(HereNow.java:29)
at com.pubnub.api.endpoints.Endpoint$1.onResponse(Endpoint.java:195)
at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:70)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6153)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:758)
HomeActivity.java
public class HomeActivity extends ParentActivity implements View.OnClickListener, OnUserLocationUpdateListener {
private PubNub pubnub;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
overridePendingTransition(R.anim.trans_left_in, R.anim.trans_left_out);
window = getWindow();
token = SharedPrefrencesHelper.getAuthToken(this);
final PNConfiguration config = new PNConfiguration();
user_id = SharedPrefrencesHelper.getUserId(context);
config.setPublishKey(Constants.PUBNUB_PUBLISH_KEY);
config.setSubscribeKey(Constants.PUBNUB_SUBSCRIBE_KEY);
config.setUuid("ASK_" + SharedPrefrencesHelper.getUserEmail(context));
config.setHeartbeatNotificationOptions(PNHeartbeatNotificationOptions.ALL);
// config.setPresenceTimeoutWithCustomInterval(5, 2);
pubnub = new PubNub(config);
pubnub.addListener(new SubscribeCallback() {
@Override
public void status(PubNub pubnub, PNStatus status) {
/* subscribeToPresence(chanelList);
changeAndSavePresence(SharedPrefrencesHelper.getPresence(HomeActivity.this));*/
}
@Override
public void message(PubNub pubnub, PNMessageResult message) {
Intent intent = new Intent("com.pubnub.update");
intent.putExtra("channel_id", message.getChannel());
intent.putExtra("DATA", String.valueOf(message.getMessage()));
sendBroadcast(intent);
}
@Override
public void presence(PubNub pubnub, PNPresenceEventResult presence) {
if (presence != null) {
String chanel = presence.getChannel();
if (!chanel.equals("ASK_" + SharedPrefrencesHelper.getUserEmail(context))) {
if (presence.getState() != null) {
String status = presence.getState().toString();
try {
JSONObject jsonObject = new JSONObject(status);
status = jsonObject.optString("isstatus", "Offline");
} catch (JSONException e) {
e.printStackTrace();
}
if (!globalArray.hereNowAskerChanelsforMentor.contains(chanel)) {
globalArray.hereNowAskerChanelsforMentor.add(chanel);
PresenceData data = new PresenceData();
data.email = chanel;
data.status = status;
globalArray.presenceArray.add(data);
} else {
int pos = globalArray.hereNowAskerChanelsforMentor.indexOf(chanel);
globalArray.presenceArray.get(pos).status = status;
}
Intent intent = new Intent("com.update.stataus");
intent.putExtra("CHANEL", chanel);
intent.putExtra("STATUS", status);
sendBroadcast(intent);
changeAndSavePresence(SharedPrefrencesHelper.getPresence(HomeActivity.this));
} else {
if (!globalArray.hereNowAskerChanelsforMentor.contains(chanel)) {
globalArray.hereNowAskerChanelsforMentor.add(chanel);
PresenceData data = new PresenceData();
data.email = chanel;
data.status = "Offline";
globalArray.presenceArray.add(data);
}
}
}
}
}
});
pubnub.subscribe().channels(Arrays.asList("ASK_" + SharedPrefrencesHelper.getUserEmail(context))).withPresence().execute();
}
if (flag.equals("peopletab")) {
title.setText(R.string.txt_people);
title.setTextColor(Color.parseColor("#ffffff"));
mCreditLinearLayout.setVisibility(View.GONE);
imgQA.setImageResource(R.drawable.question_mark);
imgMessage.setImageResource(R.drawable.message_icon);
imgMyprofile.setImageResource(R.drawable.ask_iconn);
imgPeople.setImageResource(R.drawable.people_hover);
imgMore.setImageResource(R.drawable.my_profile_icon);
mQaTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mMsgTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mAskQATabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mPeopleTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolorwithhover));
mMyAccountTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
/* if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
window.setStatusBarColor(getResources().getColor(R.color.StatusbarRed));
}*/
final Drawable drawable6 = ContextCompat.getDrawable(context, R.drawable.header_gradient_color).mutate();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mHeaderLayout.setBackground(drawable6);
} else {
mHeaderLayout.setBackgroundDrawable(drawable6);
}
imageAsk.setImageDrawable(getResources().getDrawable(R.drawable.askwhite));
// menuIcon.setImageDrawable(getResources().getDrawable(R.drawable.search_button));
txtAsk.setVisibility(View.GONE);
imageAsk.setVisibility(View.GONE);
imageView.setVisibility(View.GONE);
txtCounter.setVisibility(View.GONE);
shareImage.setVisibility(View.GONE);
txtAsk.setTextColor(Color.WHITE);
settingIcon.setVisibility(View.GONE);
title.setText("People");
title.setTextColor(Color.parseColor("#ffffff"));
menuIcon.setVisibility(View.GONE);
mImageBack.setVisibility(View.GONE);
/* if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
window.setStatusBarColor(getResources().getColor(R.color.StatusbarRed));
}*/
final Drawable drawable5 = ContextCompat.getDrawable(context, R.drawable.header_gradient_color).mutate();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mHeaderLayout.setBackground(drawable5);
} else {
mHeaderLayout.setBackgroundDrawable(drawable5);
}
PeopleMEFragment peopleFragment = new PeopleMEFragment();
FragmentManager peoplemanager = getSupportFragmentManager();
FragmentTransaction peopletransaction = peoplemanager.beginTransaction();
SharedPrefrencesHelper.saveTabValue(context, 1);
peopletransaction.replace(R.id.content_frame, peopleFragment);
peopletransaction.commit();
}
mScheduleTaskExecutor = Executors.newScheduledThreadPool(1);
mScheduleTaskExecutor.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
runOnUiThread(new Runnable() {
@Override
public void run() {
if (chanelList.size() != 0) {
config.setHeartbeatNotificationOptions(PNHeartbeatNotificationOptions.ALL);
config.setPresenceTimeoutWithCustomInterval(5, 2);
//subscribeToPresence(chanelList);
changeAndSavePresence(SharedPrefrencesHelper.getPresence(HomeActivity.this));
getChannelStatus();
}
}
});
}
}, 0, 3, TimeUnit.SECONDS);
}
@Override
public void onClick(View view) {
switch (view.getId()) { case R.id.peopleTabLayout:
Fragment peoplefragment = getSupportFragmentManager().findFragmentById(R.id.content_frame);
if (!(peoplefragment instanceof PeopleMEFragment)) {
clearBackStack();
title.setText(getString(R.string.txt_people));
mCreditLinearLayout.setVisibility(View.GONE);
imgQA.setImageResource(R.drawable.question_mark);
imgMessage.setImageResource(R.drawable.message_icon);
imgMyprofile.setImageResource(R.drawable.ask_iconn);
imgPeople.setImageResource(R.drawable.people_hover);
imgMore.setImageResource(R.drawable.my_profile_icon);
mQaTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mMsgTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mAskQATabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
mPeopleTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolorwithhover));
mMyAccountTabTxt.setTextColor(getResources().getColor(R.color.bottambarcolor));
/* if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
window.setStatusBarColor(getResources().getColor(R.color.StatusbarRed));
}*/
final Drawable drawable2 = ContextCompat.getDrawable(context, R.drawable.header_gradient_color).mutate();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mHeaderLayout.setBackground(drawable2);
} else {
mHeaderLayout.setBackgroundDrawable(drawable2);
}
title.setTextColor(Color.parseColor("#ffffff"));
menuIcon.setVisibility(View.GONE);
mImageBack.setVisibility(View.GONE);
imageAsk.setImageDrawable(getResources().getDrawable(R.drawable.askwhite));
txtAsk.setVisibility(View.GONE);
imageAsk.setVisibility(View.GONE);
imageView.setVisibility(View.GONE);
txtCounter.setVisibility(View.GONE);
shareImage.setVisibility(View.GONE);
txtAsk.setTextColor(Color.WHITE);
settingIcon.setVisibility(View.GONE);
PeopleMEFragment peopleFragment = new PeopleMEFragment();
FragmentManager peoplemanager = getSupportFragmentManager();
FragmentTransaction peopletransaction = peoplemanager.beginTransaction();
SharedPrefrencesHelper.saveTabValue(context, 1);
peopletransaction.replace(R.id.content_frame, peopleFragment);
//peopletransaction.addToBackStack(null);
peopletransaction.commit();
}
break;
}
}
private void getChannelStatus() {
try {
pubnub.hereNow().includeState(true).channels(chanelList).async(new PNCallback<PNHereNowResult>() {
@Override
public void onResponse(PNHereNowResult result, PNStatus status) {
if (status.isError()) {
// handle error
return;
}
if (result != null) {
if (result.getChannels() != null) {
for (PNHereNowChannelData entry : result.getChannels().values()) {
for (PNHereNowOccupantData occupant : entry.getOccupants()) {
String chanel_id = occupant.getUuid();
String state = String.valueOf(occupant.getState());
if (!chanel_id.equals("ASK_" + SharedPrefrencesHelper.getUserEmail(context))) {
String crappyPrefix = "null";
if (state.startsWith(crappyPrefix)) {
state = state.substring(crappyPrefix.length(), state.length());
}
if (!state.isEmpty()) {
String user_status = "";
try {
JSONObject jsonObject = new JSONObject(state);
if (jsonObject.has("isstatus")) {
user_status = jsonObject.optString("isstatus", "Offline");
}
} catch (JSONException e) {
e.printStackTrace();
}
if (!user_status.isEmpty()) {
if (!globalArray.hereNowAskerChanelsforMentor.contains(chanel_id)) {
globalArray.hereNowAskerChanelsforMentor.add(chanel_id);
PresenceData data = new PresenceData();
data.email = chanel_id;
data.status = user_status;
globalArray.presenceArray.add(data);
} else {
int pos = globalArray.hereNowAskerChanelsforMentor.indexOf(chanel_id);
globalArray.presenceArray.get(pos).status = user_status;
}
Log.d("Email", chanel_id);
Log.d("Status Channel", user_status);
Intent intent = new Intent("com.update.stataus");
intent.putExtra("CHANEL", chanel_id);
intent.putExtra("STATUS", user_status);
sendBroadcast(intent);
// changeAndSavePresence(SharedPrefrencesHelper.getPresence(HomeActivity.this));
}
}
} else if (!chanel_id.equals("MEN_" + SharedPrefrencesHelper.getUserEmail(context))) {
String crappyPrefix = "null";
if (state.startsWith(crappyPrefix)) {
state = state.substring(crappyPrefix.length(), state.length());
}
if (!state.isEmpty()) {
String user_status = "";
try {
JSONObject jsonObject = new JSONObject(state);
if (jsonObject.has("isstatus")) {
user_status = jsonObject.optString("isstatus", "Offline");
}
} catch (JSONException e) {
e.printStackTrace();
}
if (!user_status.isEmpty()) {
if (!globalArray.hereNowAskerChanelsforMentor.contains(chanel_id)) {
globalArray.hereNowAskerChanelsforMentor.add(chanel_id);
PresenceData data = new PresenceData();
data.email = chanel_id;
data.status = user_status;
globalArray.presenceArray.add(data);
} else {
int pos = globalArray.hereNowAskerChanelsforMentor.indexOf(chanel_id);
globalArray.presenceArray.get(pos).status = user_status;
}
Log.d("Email", chanel_id);
Log.d("Status Channel", user_status);
Intent intent = new Intent("com.update.stataus");
intent.putExtra("CHANEL", chanel_id);
intent.putExtra("STATUS", user_status);
sendBroadcast(intent);
// changeAndSavePresence(SharedPrefrencesHelper.getPresence(HomeActivity.this));
}
}
}
}
}
}
}
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
PeopleMEFragment.java
public class PeopleMEFragment extends Fragment implements PeopleAdapter.ChatClickCallback {
PubNub pubNub;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = getActivity();
final PNConfiguration config = new PNConfiguration();
config.setPublishKey(Constants.PUBNUB_PUBLISH_KEY);
config.setSubscribeKey(Constants.PUBNUB_SUBSCRIBE_KEY);
config.setUuid("ASK_" + SharedPrefrencesHelper.getUserEmail(context));
config.setHeartbeatNotificationOptions(PNHeartbeatNotificationOptions.ALL);
pubNub = new PubNub(config);
}
@SuppressLint("StaticFieldLeak")
private class TaskGetPeopleSearch extends AsyncTask<Void, Void, Void>{
String response = null;
PeopleModel model;
@Override
protected void onPreExecute() {
super.onPreExecute();
try {
if (AppUtility.isNotNullEmpty(getActivity())) {
progressBar.setVisibility(View.VISIBLE);
getActivity().getWindow().setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
}
} catch (Exception e) {
e.printStackTrace();
}
} @Override
protected Void doInBackground(Void... voids) {
try {
requesturl = Constants.PROTOCOL + Constants.HOST + Constants.PEOPLE_LIST_SEARCH_BY_ROLEID;JsonParser jsonParser = new JsonParser();
response = jsonParser.makeServiceCall(requesturl, token);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void vVoid){
super.onPostExecute(vVoid);
pubNub.getPresenceState().channels(Arrays.asList(channel + SharedPrefrencesHelper.getUserEmail(context)))
.uuid(channel+SharedPrefrencesHelper.getUserEmail(context)).async(new PNCallback<PNGetStateResult>() {
@Override
public void onResponse(PNGetStateResult result, PNStatus status) {
String state= result.getStateByUUID().toString().replace("[","").replace("]","").replace("\"","");
}
});
}
}
HereNow.java
public class HereNow extends Endpoint<Envelope<JsonElement>, PNHereNowResult> {
private List<String> channels;
private List<String> channelGroups;
private Boolean includeState;
private Boolean includeUUIDs;
public HereNow(PubNub pubnubInstance, TelemetryManager telemetryManager, RetrofitManager retrofit) {
super(pubnubInstance, telemetryManager, retrofit);
channels = new ArrayList<>();
channelGroups = new ArrayList<>();
}
@Override
protected List<String> getAffectedChannels() {
return channels;
}
@Override
protected List<String> getAffectedChannelGroups() {
return channelGroups;
}
@Override
protected void validateParams() throws PubNubException {
if (this.getPubnub().getConfiguration().getSubscribeKey() == null || this.getPubnub().getConfiguration().getSubscribeKey().isEmpty()) {
throw PubNubException.builder().pubnubError(PubNubErrorBuilder.PNERROBJ_SUBSCRIBE_KEY_MISSING).build();
}
}
@Override
protected Call<Envelope<JsonElement>> doWork(Map<String, String> params) {
if (includeState == null) {
includeState = false;
}
if (includeUUIDs == null) {
includeUUIDs = true;
}
String channelCSV;
if (includeState) {
params.put("state", "1");
}
if (!includeUUIDs) {
params.put("disable_uuids", "1");
}
if (channelGroups.size() > 0) {
params.put("channel-group", PubNubUtil.joinString(channelGroups, ","));
}
if (channels.size() > 0) {
channelCSV = PubNubUtil.joinString(channels, ",");
} else {
channelCSV = ",";
}
if (channels.size() > 0 || channelGroups.size() > 0) {
return this.getRetrofit().getPresenceService().hereNow(this.getPubnub().getConfiguration().getSubscribeKey(), channelCSV, params);
} else {
return this.getRetrofit().getPresenceService().globalHereNow(this.getPubnub().getConfiguration().getSubscribeKey(), params);
}
}
@Override
protected PNHereNowResult createResponse(Response<Envelope<JsonElement>> input) {
PNHereNowResult herenowData;
if (channels.size() > 1 || channelGroups.size() > 0) {
herenowData = parseMultipleChannelResponse(input.body().getPayload());
} else {
herenowData = parseSingleChannelResponse(input.body());
}
return herenowData;
}
private PNHereNowResult parseSingleChannelResponse(Envelope<JsonElement> input) {
PNHereNowResult hereNowData = PNHereNowResult.builder().totalChannels(1).channels(new HashMap<String, PNHereNowChannelData>()).totalOccupancy(input.getOccupancy()).build();
PNHereNowChannelData.PNHereNowChannelDataBuilder hereNowChannelData = PNHereNowChannelData.builder().channelName(channels.get(0)).occupancy(input.getOccupancy());
if (includeUUIDs) {
hereNowChannelData.occupants(prepareOccupantData(input.getUuids()));
hereNowData.getChannels().put(channels.get(0), hereNowChannelData.build());
}
return hereNowData;
}
private PNHereNowResult parseMultipleChannelResponse(JsonElement input) {
MapperManager mapper = getPubnub().getMapper();
PNHereNowResult hereNowData = PNHereNowResult.builder().channels(new HashMap<String, PNHereNowChannelData>()).totalChannels(mapper.elementToInt(input, "total_channels")).totalOccupancy(mapper.elementToInt(input, "total_occupancy")).build();
for (Iterator<Map.Entry<String, JsonElement>> it = mapper.getObjectIterator(input, "channels"); it.hasNext(); ) {
Map.Entry<String, JsonElement> entry = it.next();
PNHereNowChannelData.PNHereNowChannelDataBuilder hereNowChannelData = PNHereNowChannelData.builder().channelName(entry.getKey()).occupancy(mapper.elementToInt(entry.getValue(), "occupancy"));
if (includeUUIDs) {
hereNowChannelData.occupants(prepareOccupantData(mapper.getField(entry.getValue(), "uuids")));
} else {
hereNowChannelData.occupants(null);
}
hereNowData.getChannels().put(entry.getKey(), hereNowChannelData.build());
}
return hereNowData;
}
private List<PNHereNowOccupantData> prepareOccupantData(JsonElement input) {
List<PNHereNowOccupantData> occupantsResults = new ArrayList<>();
MapperManager mapper = getPubnub().getMapper();
if (includeState != null && includeState) {
for (Iterator<JsonElement> it = mapper.getArrayIterator(input); it.hasNext(); ) {
JsonElement occupant = it.next();
PNHereNowOccupantData.PNHereNowOccupantDataBuilder hereNowOccupantData = PNHereNowOccupantData.builder();
hereNowOccupantData.uuid(mapper.elementToString(occupant, "uuid"));
hereNowOccupantData.state(mapper.getField(occupant, "state"));
occupantsResults.add(hereNowOccupantData.build());
}
} else {
for (Iterator<JsonElement> it = mapper.getArrayIterator(input); it.hasNext(); ) {
JsonElement occupant = it.next();
PNHereNowOccupantData.PNHereNowOccupantDataBuilder hereNowOccupantData = PNHereNowOccupantData.builder();
hereNowOccupantData.uuid(mapper.elementToString(occupant));
hereNowOccupantData.state(null);
occupantsResults.add(hereNowOccupantData.build());
}
}
return occupantsResults;
}
}
由于角色限制，课程没有完整的代码，所以我添加了所有细节，但我可能是崩溃的原因。 请帮助，因为我在最近几天坚持这一点。
答案 0 :(得分：1)
您的片段对象可能为null。请在if语句中添加一个空检查，如下所示：
public void onClick(View view) {
switch (view.getId()) { case R.id.peopleTabLayout:
Fragment peoplefragment = getSupportFragmentManager().findFragmentById(R.id.content_frame);
if (peoplefragment != null && !(peoplefragment instanceof PeopleMEFragment)) {
clearBackStack();
在尝试引用片段之前，请务必在检索片段的任何位置执行此操作。