I am a newbie and trying to create a video player .I am getting a null pointer exception and have read all the questions on SO and searched google related to it and read it. thumbpath doesn't seem null to me although it maybe the only reason of this exception. Can anyone help me with it ? Thanks
SDVideos.java
package com.example.dell_1.myapp3;
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
public class SDVideos extends Activity
{
private Cursor videoCursor;
private int videoColumnIndex;
ListView videolist;
int count;
String thumbPath;
String[] thumbColumns = { MediaStore.Video.Thumbnails.DATA,MediaStore.Video.Thumbnails.VIDEO_ID };
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sdvideos);
initialization();
}
private void initialization()
{
System.gc();
String[] videoProjection = { MediaStore.Video.Media._ID,MediaStore.Video.Media.DATA,
MediaStore.Video.Media.DISPLAY_NAME,MediaStore.Video.Media.SIZE };
videoCursor =getContentResolver().query(MediaStore.Video.Media.EXTERNAL_CONTENT_URI,videoProjection, null, null, null);
count = videoCursor.getCount();
videolist = (ListView) findViewById(R.id.PhoneVideoList);
videolist.setAdapter(new VideoListAdapter(this.getApplicationContext()));
videolist.setOnItemClickListener(videogridlistener);
}
private AdapterView.OnItemClickListener videogridlistener = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position, long id)
{
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
videoCursor.moveToPosition(position);
String filename = videoCursor.getString(videoColumnIndex);
Log.i("FileName: ", filename);
//Intent intent = new Intent(VideoActivity.this, ViewVideo.class);
//intent.putExtra("videofilename", filename);
//startActivity(intent);
}};
public class VideoListAdapter extends BaseAdapter
{
private Context vContext;
public VideoListAdapter(Context c)
{
vContext = c;
}
public int getCount()
{
return videoCursor.getCount();
}
public Object getItem(int position)
{
return position;
}
public long getItemId(int position)
{
return position;
}
public View getView(int position, View convertView, ViewGroup parent)
{
View listItemRow;
listItemRow = LayoutInflater.from(vContext).inflate(R.layout.listitem, parent, false);
TextView txtTitle = (TextView)listItemRow.findViewById(R.id.txtTitle);
TextView txtSize = (TextView)listItemRow.findViewById(R.id.txtSize);
ImageView thumbImage = (ImageView)listItemRow.findViewById(R.id.imgIcon);
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME);
videoCursor.moveToPosition(position);
txtTitle.setText(videoCursor.getString(videoColumnIndex));
videoColumnIndex = videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE);
videoCursor.moveToPosition(position);
txtSize.setText(" Size(KB):" + videoCursor.getString(videoColumnIndex));
int videoId = videoCursor.getInt(videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
Cursor videoThumbnailCursor =getContentResolver().query(MediaStore.Video.Thumbnails.EXTERNAL_CONTENT_URI,
thumbColumns, MediaStore.Video.Thumbnails.VIDEO_ID+ "=" + videoId, null, null);
if (videoThumbnailCursor.moveToFirst())
{
thumbPath = videoThumbnailCursor.getString(videoThumbnailCursor.getColumnIndex(MediaStore.Video.Thumbnails.DATA));
Log.i("ThumbPath: ",thumbPath);
}
thumbImage.setImageURI(Uri.parse(thumbPath));
return listItemRow;
}
}
}
XML File :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:id="@+id/PhoneVideoList"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="#242424"
android:dividerHeight="1dp"/>
</LinearLayout>
LOGCAT :
08-05 17:29:17.109 17708-17708/com.example.dell_1.myapp3 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.dell_1.myapp3, PID: 17708
java.lang.NullPointerException: uriString
at android.net.Uri$StringUri.<init>(Uri.java:475)
at android.net.Uri$StringUri.<init>(Uri.java)
at android.net.Uri.parse(Uri.java:437)
at com.example.dell_1.myapp3.SDVideos$VideoListAdapter.getView(SDVideos.java:112)
at android.widget.AbsListView.obtainView(AbsListView.java:2367)
at android.widget.ListView.makeAndAddView(ListView.java:1972)
at android.widget.ListView.fillDown(ListView.java:704)
at android.widget.ListView.fillFromTop(ListView.java:765)
at android.widget.ListView.layoutChildren(ListView.java:1744)
at android.widget.AbsListView.onLayout(AbsListView.java:2161)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5618)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5618)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5618)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5618)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at com.android.internal.policy.DecorView.onLayout(DecorView.java:724)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5618)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2374)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2101)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1278)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6357)
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)
答案 0 :(得分：0)
I don´t see any reason why thumbPath needs to be an field of SDVideos, it is only used inside VideoListAdapter.getView.
Your updated code of moving thumbPath as a variable would be the following:
int videoId = videoCursor.getInt(videoCursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
Cursor videoThumbnailCursor =getContentResolver().query(MediaStore.Video.Thumbnails.EXTERNAL_CONTENT_URI,
thumbColumns, MediaStore.Video.Thumbnails.VIDEO_ID+ "=" + videoId, null, null);
if (videoThumbnailCursor.moveToFirst())
{
String thumbPath = videoThumbnailCursor.getString(videoThumbnailCursor.getColumnIndex(MediaStore.Video.Thumbnails.DATA));
Log.i("ThumbPath: ",thumbPath);
thumbImage.setImageURI(Uri.parse(thumbPath));
}
return listItemRow;
Since the thumbPath will only be populated if the cursor have any data, you can move the setImageURI to inside your if.
This code will solve the NullPointerException, but probably you will not see any image in the thumbImage.
Now you need to find why your videoThumbnailCursor is returning no data. After you find why, please update your question.