Null Pointer Exception when using handler.obtainmessage
I am using a handler to pass the value of a variable to the UI thread in android. However, the application crashes as soon as it reaches the handler. Any idea to fix it would be a great help. Here is my code:
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Thank you in advance
Here is the complete threD code:
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.media.MediaMetadataRetriever;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
public class FrameProcessor extends Thread {
private Uri uri = null;
private Handler mHandler = null;
private static volatile boolean bKeepRunning = true;
private String value = null;
private Context context = null;
public FrameProcessor(Object obj, Handler handler, Uri uri) {
if (obj != null) {
this.uri = uri;
this.mHandler = handler;
}
this.context = (Context) obj;
}
public void setIndex(String val) {
this.value = val;
}
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public void run() {
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
retriever.setDataSource(uri.toString(), new HashMap<String, String>());
Log.v("FrameProcessor", "Video path set.... ");
ArrayList<Bitmap> rev = new ArrayList<Bitmap>();
Log.v("FrameProcessor", "uri is: " + uri);
MediaPlayer mp = MediaPlayer.create(context, uri);
Log.v("FrameProcessor", "MP created ");
int millis = mp.getDuration();
for (int i = 1000000; i < millis * 1000; i += 1000000) {
Log.v("FrameProcessor", "In Thread for loop ");
Bitmap bitmap = retriever.getFrameAtTime(i,
MediaMetadataRetriever.OPTION_CLOSEST_SYNC);
rev.add(bitmap);
try {
saveFrames(rev);
} catch (IOException e) {
e.printStackTrace();
}
}
}
@SuppressLint("ShowToast")
public void saveFrames(ArrayList<Bitmap> saveBitmapList) throws IOException {
Log.v("FrameProcessor", "In saveFrames ");
if (value != null) {
Log.v("FrameProcessor", value);
if (value.equals("0")) {
uri = Uri
.parse("http://html5dev.anorakstech.com/videos/video.mp4");
} else if (value.equals("1")) {
uri = Uri
.parse("http://html5dev.anorakstech.com/videos/HSNvideo.mp4");
} else if (value.equals("2")) {
uri = Uri
.parse("http://html5dev.anorakstech.com/videos/HSNMarkVideo.mp4");
}
Log.v("FrameProcessor", uri.toString());
} else {
}
if (value.equals("0")) {
String folder = Environment.getExternalStorageDirectory()
.toString();
File saveFolder = new File(folder + "/Movies/Frames/");
if (!saveFolder.exists()) {
saveFolder.mkdirs();
Log.v("FrameProcessor", "Extracting Frames.... ");
}
int i = 1;
for (Bitmap b : saveBitmapList) {
Log.v("FrameProcessor", "In saveFrames for loop");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
b.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
File f = new File(saveFolder, ("frame" + i + ".jpg"));
f.createNewFile();
if (i >= 0 && i < 6) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i >= 6 && i < 12) {
**String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();**
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i >= 12 && i < 18) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i > 18 && i < 24) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else {
}
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.flush();
fo.close();
i++;
}
} else if (value.equals("1")) {
String folder = Environment.getExternalStorageDirectory()
.toString();
File saveFolder = new File(folder + "/Movies/Frames/");
if (!saveFolder.exists()) {
saveFolder.mkdirs();
Log.v("FrameProcessor", "Extracting Frames.... ");
}
int i = 1;
for (Bitmap b : saveBitmapList) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
b.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
File f = new File(saveFolder, ("frame" + i + ".jpg"));
f.createNewFile();
if (i >= 0 && i < 6) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i >= 6 && i < 12) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i >= 12 && i < 18) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else if (i > 18 && i < 24) {
String var = "NO Keyword Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "NO Keyword Found");
} else {
}
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.flush();
fo.close();
i++;
}
} else {
String folder = Environment.getExternalStorageDirectory()
.toString();
File saveFolder = new File(folder + "/Movies/Frames/");
if (!saveFolder.exists()) {
saveFolder.mkdirs();
Log.v("FrameProcessor", "Extracting Frames.... ");
}
int i = 1;
while (bKeepRunning) {
for (Bitmap b : saveBitmapList) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
b.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
File f = new File(saveFolder, ("frame" + i + ".jpg"));
f.createNewFile();
if (i >= 0 && i < 6) {
String var = "Keyword HSN Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
completeMessage.sendToTarget();
Log.v("FrameProcessor", "Keyword ABCFound");
} else if (i >= 6 && i < 12) {
String var = "Keyword HSN Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
Log.v("FrameProcessor", "Keyword SHOP Found");
} else if (i >= 12 && i < 18) {
String var = "Keyword HSN Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
Log.v("FrameProcessor", "Keyword BY Found");
} else if (i > 18 && i < 24) {
String var = "Keyword HSN Found";
Message completeMessage = mHandler.obtainMessage();
completeMessage.obj = var;
Log.v("FrameProcessor", "Keyword REMOTE Found");
} else {
}
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.flush();
fo.close();
i++;
}
}
}
}
public void kill() {
bKeepRunning = false;
}
}
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