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Android

NullPointerException

Hitting nullPointerException within MessageAdapter at line message.getString(ParseContants.KEY_FILE_TYPE).equals(ParseContants.TYPE_IMAGE));

This error make my application crashes. Any help will be appreciated. Thank you

Seth Kroger
Seth Kroger
56,407 Points

It would be helpful if you could post your code, so we can see what's happening leading up to that line.

Below is the code that i have inside MessageAdapter.

package com.mobileapps.blogsocial;

import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.ImageView; import android.widget.TextView;

import com.parse.ParseObject;

import java.util.List;

/**

  • Created by Android on 7/9/2015. */ public class MessageAdapter extends ArrayAdapter<ParseObject> {

    public static final String TAG = MessageAdapter.class.getSimpleName();

    protected Context mContext; protected List<ParseObject> mMessages;

    public MessageAdapter(Context context, List<ParseObject> messages) { super(context, R.layout.message_item, messages); mContext = context; mMessages = messages; Log.d("Message initialized:", "" + mMessages); }

    @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder;

    if(convertView == null) {
        convertView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
        holder = new ViewHolder();
        holder.iconImageView = (ImageView) convertView.findViewById(R.id.messageIcon);
        holder.nameLabel = (TextView) convertView.findViewById(R.id.senderLabel);
    }else {
        holder = (ViewHolder) convertView.getTag();
    }
    
    ParseObject message = mMessages.get(position);
    

    /* Log.e(TAG, "Parse User: " + message); Log.e(TAG, "KEY_FILE_TYPE: " + ParseConstants.KEY_FILE_TYPE); Log.e(TAG, message.getString(ParseConstants.KEY_FILE_TYPE));*/ if (ParseConstants.TYPE_IMAGE.equals(message.getString(ParseConstants.KEY_FILE_TYPE))) { holder.iconImageView.setImageResource(R.drawable.ic_action_picture); } else { holder.iconImageView.setImageResource(R.drawable.ic_action_play_over_video); } holder.nameLabel.setText(message.getString(ParseConstants.KEY_SENDER_NAME));

    return convertView;
    

    }

    private static class ViewHolder { ImageView iconImageView; TextView nameLabel; }

}

Here is the Code i have inside InboxFragment class

package com.mobileapps.blogsocial;

import java.util.List;

import android.os.Bundle; import android.support.v4.app.ListFragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter;

import com.parse.FindCallback; import com.parse.ParseException; import com.parse.ParseObject; import com.parse.ParseQuery; import com.parse.ParseUser;

public class InboxFragment extends ListFragment {

protected List<ParseObject> mMessages;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_inbox,
            container, false);

    return rootView;
}

@Override
public void onResume() {
    super.onResume();

    getActivity().setProgressBarIndeterminateVisibility(true);

    ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(ParseConstants.CLASS_MESSAGES);
    query.whereEqualTo(ParseConstants.KEY_RECIPIENT_IDS, ParseUser.getCurrentUser().getObjectId());
    query.addDescendingOrder(ParseConstants.KEY_CREATED_AT);
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> messages, ParseException e) {
            getActivity().setProgressBarIndeterminateVisibility(false);
            if (e == null) {
                //We found messages!
                mMessages = messages;

                String[] usernames = new String[mMessages.size()];
                int i = 0;
                for(ParseObject message : mMessages) {
                   usernames[i] = message.getString(ParseConstants.KEY_SENDER_NAME);
                    i++;
                }
                MessageAdapter adapter = new MessageAdapter(
                        getListView().getContext(),
                        messages);
                setListAdapter(adapter);
            }
        }
    });
}

}

2 Answers

faraz
PLUS
faraz
Courses Plus Student 21,474 Points

Make sure you check if the message != null, that may be your problem. Also, what are you trying to do here?

 if(convertView == null) {
        convertView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
        holder = new ViewHolder();
        holder.iconImageView = (ImageView) convertView.findViewById(R.id.messageIcon);
        holder.nameLabel = (TextView) convertView.findViewById(R.id.senderLabel);
    }else {
        holder = (ViewHolder) convertView.getTag();
    }

faraz i am simply trying to inflate the inboxFragment in that block of code. The first time it method getView() get called convertView will be null but once it get populated it won't be null anymore, and i will simply have to reuse it if the user ever scroll of the screen. That is why i'm doing that. And Ben has discussed it on the video as well.

faraz
PLUS
faraz
Courses Plus Student 21,474 Points

Try downloading the source code from the "Teachers Notes" and comparing it to your code.