尝试加载应用程序时，我收到了意外的nullpoint异常错误。我不确定出了什么问题，并且花了一段时间试图解决这个问题。 我在logcat消息中包含了以下内容：
09-01 22:26:44.311: E/AndroidRuntime(5805): at com.dooba.beta.Fragment1$3.done(Fragment1.java:280)
09-01 22:44:46.383: E/AndroidRuntime(6035): java.lang.NullPointerException
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.dooba.beta.Fragment1$3.done(Fragment1.java:281)
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.parse.FindCallback.internalDone(FindCallback.java:45)
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.parse.FindCallback.internalDone(FindCallback.java:31)
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.parse.Parse$5$1.run(Parse.java:891)
09-01 22:44:46.383: E/AndroidRuntime(6035): at android.os.Handler.handleCallback(Handler.java:733)
09-01 22:44:46.383: E/AndroidRuntime(6035): at android.os.Handler.dispatchMessage(Handler.java:95)
09-01 22:44:46.383: E/AndroidRuntime(6035): at android.os.Looper.loop(Looper.java:136)
09-01 22:44:46.383: E/AndroidRuntime(6035): at android.app.ActivityThread.main(ActivityThread.java:5017)
09-01 22:44:46.383: E/AndroidRuntime(6035): at java.lang.reflect.Method.invokeNative(Native Method)
09-01 22:44:46.383: E/AndroidRuntime(6035): at java.lang.reflect.Method.invoke(Method.java:515)
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-01 22:44:46.383: E/AndroidRuntime(6035): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-01 22:44:46.383: E/AndroidRuntime(6035): at dalvik.system.NativeStart.main(Native Method)
下面是活动代码
public class Fragment1 extends Fragment {
public interface Constants {
String LOG = "com.dooba.beta";
}
private String currentUserId;
private ArrayAdapter<String> namesArrayAdapter;
private ArrayList<String> names;
private ArrayList<String> age;
private ArrayList<String> headline;
private ArrayList<String> activityname;
protected TextView mUserRetrieved;
protected TextView mUserActivityNameRetrieved;
protected TextView mUserNameRetrieved;
protected TextView mUserAgeRetrieved;
protected TextView mUserHeadlineRetrieved;
private ArrayList<Images> alProfilePicture;
private ListView usersListView;
private Button logoutButton;
String userGender = ParseUser.getCurrentUser().getString("Gender");
String activityName = ParseUser.getCurrentUser().getString("ActivityName");
Number maxDistance = ParseUser.getCurrentUser().getNumber(
"Maximum_Distance");
String userLookingGender = ParseUser.getCurrentUser().getString(
"Looking_Gender");
Number minimumAge = ParseUser.getCurrentUser().getNumber("Minimum_Age");
Number maximumAge = ParseUser.getCurrentUser().getNumber("Maximum_Age");
Number userage = ParseUser.getCurrentUser().getNumber("UserAge");
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setConversationsList();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1_layout, container,
false);
//mUserRetrieved = (TextView) getActivity().findViewById(R.id.userlistname);
Button newPage = (Button)view.findViewById(R.id.btnMatchConfirm);
newPage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// ParseUser currentUser = ParseUser.getCurrentUser();
// currentUser.put("UserMatchName", mUserRetrieved);
Intent intent = new Intent(getActivity(), matchOptionActivity.class);
startActivity(intent);
}
});
return view;
}
private void setConversationsList() {
currentUserId = ParseUser.getCurrentUser().getObjectId();
names = new ArrayList<String>();
age = new ArrayList<String>();
headline = new ArrayList<String>();
activityname = new ArrayList<String>();
alProfilePicture = new ArrayList<Images>();
// String userActivitySelectionName = null;
ParseQuery<ParseUser> query = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
query.orderByDescending("Name");
ParseQuery<ParseUser> query1 = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query1.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query1.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query1.whereEqualTo("Looking_Gender", userGender);
query1.setLimit(1);
query1.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
ParseQuery<ParseUser> query11 = ParseUser.getQuery();
//query.whereEqualTo("ActivityName",userActivitySelectionName);
query11.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query11.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query11.whereEqualTo("Looking_Gender", userGender);
query11.setLimit(1);
query11.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
ParseQuery<ParseUser> query4 = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query4.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query4.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query4.whereEqualTo("Looking_Gender", userGender);
query4.setLimit(1);
query4.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
ParseQuery<ParseUser> query5 = ParseUser.getQuery();
// query.whereEqualTo("ActivityName",userActivitySelectionName);
query5.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query5.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query5.whereEqualTo("Looking_Gender", userGender);
query5.setLimit(1);
query5.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
// whereWithinKilometers("Maximum_distance", point, double maxDistance);
Log.d(Constants.LOG, "");
query.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> objects,ParseException e) {
for(int i=0;i<objects.size();i++){
// Do whatever you need to extract object from "users"
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
query.orderByDescending("Name");
ParseFile image = objects.get(i).getParseFile("ProfilePicture");
ParseImageView imageView = (ParseImageView) getView().findViewById(R.id.profilePictureresult);
// The placeholder will be used before and during the fetch, to be replaced by the fetched image
// data.
imageView.setPlaceholder(getResources().getDrawable(R.drawable.profile_pict));
imageView.setParseFile(image);
imageView.loadInBackground(new GetDataCallback() {
@Override
public void done(byte[] data, ParseException e) {
if (data != null) {
Log.i("ParseImageView", "Fetched: " + data.length);
} else {
Log.e("ParseImageView", "Error fetching: " + e.getMessage());
}
}
});
}
}//for loop
});
query1.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> objects,ParseException e) {
for(int i=0;i<objects.size();i++){
// Do whatever you need to extract object from "users"
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
mUserNameRetrieved = (TextView) getActivity().findViewById(R.id.userlistname);
mUserNameRetrieved.setText(objects.get(i).get("Name").toString());
}
}//for loop
});
query11.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> objects,ParseException e) {
for(int i=0;i<objects.size();i++){
// Do whatever you need to extract object from "users"
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
mUserHeadlineRetrieved = (TextView) getActivity().findViewById(R.id.userlistheadline);
mUserHeadlineRetrieved.setText(objects.get(i).get("Headline").toString());
}
}//for loop
});
query4.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> objects,ParseException e) {
for(int i=0;i<objects.size();i++){
// Do whatever you need to extract object from "users"
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
mUserActivityNameRetrieved = (TextView) getActivity().findViewById(R.id.userlistactivityname);
mUserActivityNameRetrieved.setText(objects.get(i).get("ActivityName").toString());
}
}//for loop
});
query5.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> objects,ParseException e) {
for(int i=0;i<objects.size();i++){
// Do whatever you need to extract object from "users"
ParseQuery<ParseObject> query = ParseQuery.getQuery("User");
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
mUserAgeRetrieved = (TextView) getActivity().findViewById(R.id.userlistage);
mUserAgeRetrieved.setText(objects.get(i).get("Age").toString());
}
}//for loop
});
}
public void openConversation(ArrayList<String> names, int pos) {
ParseQuery<ParseUser> query = ParseUser.getQuery();
query.whereNotEqualTo("objectId", ParseUser.getCurrentUser()
.getObjectId());
// users with Gender = currentUser.Looking_Gender
query.whereEqualTo("Gender", userLookingGender);
// users with Looking_Gender = currentUser.Gender
query.whereEqualTo("Looking_Gender", userGender);
query.setLimit(1);
query.whereEqualTo("ActivityName", activityName);
query.whereGreaterThanOrEqualTo("UserAge", minimumAge);
query.whereLessThanOrEqualTo("UserAge", maximumAge);
query.findInBackground(new FindCallback<ParseUser>() {
public void done(List<ParseUser> user, ParseException e) {
if (e == null) {
Intent intent = new Intent(getActivity()
.getApplicationContext(), MessagingActivity.class);
intent.putExtra("Name", user.get(0).getObjectId());
startActivity(intent);
} else {
Toast.makeText(getActivity().getApplicationContext(),
"Error finding that user", Toast.LENGTH_SHORT)
.show();
}
}
});
}
}
提前致谢
答案 0 :(得分：0)
此行中NullPointerException（一个未初始化的对象）可能有很多原因：
mUserNameRetrieved.setText(objects.get(i).get("Name").toString());
我建议您添加以下支票：
ParseObject object = objects.get(i);
if (object != null) {
String name = object.get("Name");
mUserNameRetrieved.setText(name);
}
无论如何，您正在尝试将“Name”的值设置为循环内的mUserNameRetrieved。这将只显示姓氏。如果你正在调试代码，你应该使用类似的东西：
Log.d("Name value", name);
我希望能帮到你！