title: I am getting a null pointer exception in my custom adapter getView() method
body: <p>java.lang.NullPointerException: name is null</p>
  
  <pre><code>  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
  
      Holder holder;
      if (convertView == null) {
          holder = new Holder();
          LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
          convertView = vi.inflate(R.layout.history_item, parent, false);
  
          holder.tvCat = (TextView)convertView.findViewById(R.id.tv_category);
          holder.tvAmt = (TextView)convertView.findViewById(R.id.tv_amount);
          holder.tvDate = (TextView)convertView.findViewById(R.id.tv_date);
          holder.img = (ImageView)convertView.findViewById(R.id.iv);
          convertView.setTag(holder);
  
      }
  
      holder=(Holder)convertView.getTag();
      //Holder holder = new Holder();
      //View rowView;
      HistoryItem historyItem;
      //rowView=inflater.inflate(R.layout.history_item,null);
  
      historyItem = historyItems.get(position);
  
      holder.tvCat.setText(historyItem.getCategory());
      holder.tvAmt.setText(historyItem.getAmount()+"");
  
      DateFormat df = new SimpleDateFormat("yyyy/MM/dd kk:mm:ss");
      Calendar c    = Calendar.getInstance();
      c.setTimeInMillis(historyItem.getTimestamp());
      Date day      = c.getTime();
  
      holder.tvDate.setText(df.format(day));
  
      Resources res = context.getResources();
      String mDrawableName = iconMapper.get(historyItem.getCategory());
  
      //This line is giving the null pointer exception...
      int resID = res.getIdentifier(mDrawableName , "drawable", context.getPackageName());
  
      holder.img.setImageResource(resID);
  
      return convertView;
  }
  </code></pre>
  
  <p>I checked mDrawableName and it holds the correct value.<br>
  Also, the context is coming from my ListView class.<br>
  Any help would be appreciated.</p>
  
  <p>Logcat : </p>
  
  <pre><code>java.lang.NullPointerException: name is null
                                                                                     at android.content.res.ResourcesImpl.getIdentifier(ResourcesImpl.java:214)
                                                                                     at android.content.res.Resources.getIdentifier(Resources.java:1866)
                                                                                     at com.example.sharang.wheresmymoney.HistoryCustomAdapter.getView(HistoryCustomAdapter.java:92)
                                                                                     at com.baoyz.swipemenulistview.SwipeMenuAdapter.getView(SwipeMenuAdapter.java:49)
                                                                                     at android.widget.AbsListView.obtainView(AbsListView.java:2369)
                                                                                     at android.widget.ListView.makeAndAddView(ListView.java:1970)
                                                                                     at android.widget.ListView.fillDown(ListView.java:704)
                                                                                     at android.widget.ListView.fillFromTop(ListView.java:765)
                                                                                     at android.widget.ListView.layoutChildren(ListView.java:1744)
                                                                                     at android.widget.AbsListView.onLayout(AbsListView.java:2161)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
                                                                                     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
                                                                                     at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                                                                                     at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.support.v7.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:433)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                                                                                     at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
                                                                                     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
                                                                                     at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
                                                                                     at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
                                                                                     at com.android.internal.policy.DecorView.onLayout(DecorView.java:724)
                                                                                     at android.view.View.layout(View.java:17526)
                                                                                     at android.view.ViewGroup.layout(ViewGroup.java:5612)
                                                                                     at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2342)
                                                                                     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2069)
                                                                                     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1246)
                                                                                     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6307)
                                                                                     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:871)
                                                                                     at android.view.Choreographer.doCallbacks(Choreographer.java:683)
                                                                                     at android.view.Choreographer.doFrame(Choreographer.java:619)
                                                                                     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857)
                                                                                     at android.os.Handler.handleCallback(Handler.java:751)
                                                                                     at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                     at android.os.Looper.loop(Looper.java:154)
                                                                                     at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                                     at java.lang.reflect.Method.invoke(Native Method)
                                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
                                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
  </code></pre>