Android: Base Adapter Weird Null Pointer -

sorry title issue cannot seem summarise

so made class extends autocompletetextview

i made base adapter class implements filterable interface

i set adapter

i null pointer when getcount called states array list null. things weird

this base adapter constructor

public piecesearchadapter(context context, arraylist<food> food) {     mcontext = context;     mfoods = new arraylist<>();     mfoods.addall(food); } 

the above have after diagnosed issue

so impossible array list null now

  @override     public int getcount() {         return mfoods.size();     } 

the null pointer still occurs

so debugged @ point in base adapter constructor. items passed in not null , contain items.

i not sure issue is.

stack trace:

 java.lang.nullpointerexception             @ redacted.foodsearchadapter.getcount(piecesearchadapter.java:36)             @ android.widget.autocompletetextview$popupdatasetobserver$1.run(autocompletetextview.java:1291)             @ android.os.handler.handlecallback(handler.java:733)             @ android.os.handler.dispatchmessage(handler.java:95)             @ android.os.looper.loop(looper.java:157)             @ android.app.activitythread.main(activitythread.java:5356)             @ java.lang.reflect.method.invokenative(native method)             @ java.lang.reflect.method.invoke(method.java:515)             @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:1265)             @ com.android.internal.os.zygoteinit.main(zygoteinit.java:1081)             @ dalvik.system.nativestart.main(native method) 

tried karan mer solution

private list<food> mfoods;  public piecesearchadapter(context context, arraylist<food> food) {     mcontext = context;     mfoods =  new arraylist<food>(food); } 

same problem

checking size of mfoods array in constructor

 public piecesearchadapter(context context, arraylist<food> food) {         mcontext = context;         mfoods = new arraylist<>(food);         if(mfoods == null){             debugutils.log("yes null");         }         else{             debugutils.log("not null, size " + mfoods.size());         }     } 

output was

not null, size 11 

rohan solution

not try catch same thing

@override public int getcount() {     if(mpieces != null){         return mpieces.size();     }     return 0; } 

does not crash, following exception when changing text of autocompletetextview run filter operation.

344-962/w/filter﹕ exception occured during performfiltering()!     java.lang.nullpointerexception             @ redacted.foodsearchadapter$foodfilter.performfiltering(foodsearchadapter.java:108)             @ android.widget.filter$requesthandler.handlemessage(filter.java:234)             @ android.os.handler.dispatchmessage(handler.java:102)             @ android.os.looper.loop(looper.java:157)             @ android.os.handlerthread.run(handlerthread.java:61) 

this line 108. starts

for (food food : mfood) {                     if (food.getreferencenumber().matches("(?i:.*" + constraint + ".*)") || piece.getname().matches("(?i:.*" + constraint + ".*)")) {                         filteredfoods.add(food);                     }                 } 

basically member mfoods null again :(

my entire filter logic

private class foodfilter extends filter {          /**          * filter data based on pattern in worker thread          *          * @return filterresults: contains 2 members, count indicating amount of results , data          */         @override         protected filterresults performfiltering(charsequence constraint) {             filterresults results = new filterresults();              //do have constraints passed in?             if (!textutils.isempty(constraint)) {                 arraylist<food> filteredfood = new arraylist<>();                 (food food : mfood) {                     if (food.getreferencenumber().matches("(?i:.*" + constraint + ".*)") || food.getname().matches("(?i:.*" + constraint + ".*)")) {                         filteredfood.add(food);                     }                 }                 results.count = filteredfood.size();                 results.values = filtered;             }             return results;         } 

and publishresults method

 @override         protected void publishresults(charsequence charsequence, filterresults filterresults) {             if (filterresults != null) {                 mfood = (arraylist<food>) filterresults.values;                 notifydatasetchanged();             }          } 

more weird. array adapter works me not base adapter

arrayadapter<food> adapter = new arrayadapter<>(getactivity(), android.r.layout.simple_dropdown_item_1line, food); 

and in tostring method of food model

@override public string tostring() {     return mname; } 

so there wrong base adapter im not sure. @ least proves data supplying otherwise not work.

fixed issue.

i had number of problems bojan llievski , rohan pawar pointed out

the key issue here

 @override         protected void publishresults(charsequence charsequence, filterresults filterresults) {             if (filterresults != null) {                 mfood = (arraylist<food>) filterresults.values;                 notifydatasetchanged();             }          } 

so filterresults never null values member can null here setting mfood member null when no results found. , since did not set threshold, no characters instantly make member array list null hense null pointer.

the solution create array list this

 private arraylist<food> moriginalfoodpieces;     private arraylist<food> mfilteredpiecestoshow = new arraylist<>();      private final context mcontext;      public piecesearchadapter(context context, arraylist<food> food) {         mcontext = context;         moriginalfood = food;     } 

so other methods getcount , getview use mfilteredpiecestoshow array list. not touch moriginalfood array list need preserve data set filtering.

and publishresults method looks this

@override         protected void publishresults(charsequence charsequence, filterresults filterresults) {             debugutils.log("publishresults called");                 object filterresult = filterresults.values;                 if(filterresult != null){                     mfilteredfoodtoshow = (arraylist<food>) filterresult;                 }                 else{                     mfilteredfoodtoshow.clear();                 }                 notifydatasetchanged();         }