Sorry If I make mistake, I'm newbie in this forum and newbie in learning android programming
On Mar 23, 7:41 am, Lew <[email protected]> wrote: > Hery Irawan wrote: > > Hi, I want to create motion detection app, but I still have a problem > > with my code > > You have many problems with your code. I think you're getting > 'NullPointerException' (NPE). Do you see this in your "logcat"? > > As TreKing has told you (twice!) you must tell us what is wrong. "I have a > problem" is a very useless way to ask a question. > > What *precisely* is the behavior you experience, and how *exactly* does it > differ from the *exact* behaviors you expect? > > *Copy and paste* and error message into your report (such as the NPE > messages you surely are getting). > > What have you done to diagnose your problem? (Writing to a programming > forum doesn't count.) > > > > > > > > > > > Here my code: > > > package com.iseng; > > > import java.io.File; > > import java.io.FileNotFoundException; > > import java.io.FileOutputStream; > > import java.io.IOException; > > import java.io.OutputStream; > > > import android.app.Activity; > > import android.content.ContentValues; > > import android.content.pm.ActivityInfo; > > import android.content.res.Configuration; > > import android.net.Uri; > > import android.os.Bundle; > > import android.os.Environment; > > import android.provider.MediaStore.Images.Media; > > import android.util.Log; > > import android.view.SurfaceHolder; > > import android.view.SurfaceView; > > import android.widget.Toast; > > import android.hardware.*; > > import android.hardware.Camera.PictureCallback; > > > public class IsengActivity extends Activity implements > > SurfaceHolder.Callback, Camera.PreviewCallback, PictureCallback { > > Please be consistent and conventional with indentation. Use spaces (not > TABs) to indent, up to four (though two works well) per level for forum > posts. > > > Camera kamera; > > SurfaceHolder surface; > > SurfaceView kameraview; > > The Java naming convention would suggest 'kameraView' as the variable name. > > > public byte dataOld[]; > > This is 'null' to start with (hence your NPEs) and should not be 'public'. > > > public void onCreate(Bundle savedInstanceState) { > > super.onCreate(savedInstanceState); > > setContentView(R.layout.main); > > > setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); > > kameraview =(SurfaceView) findViewById(R.id. kameraku); > > surface = kameraview.getHolder(); > > surface.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); > > surface.addCallback(this); > > } > > @Override > > public void onPreviewFrame(byte[] data, Camera kamera) { > > > if(data.length ==0) return; > > What if 'data == null'? > > > if(dataOld.length==0 ) > > 'dataOld' certainly is 'null' the first time. > NPE! > > > data=dataOld; > > You forgot the curly braces around the 'if' body. > > If 'dataOld' is not 'null' and is empty, it will wipe out 'data' at this > point. Is that what you want? The logic is not obvious and should be > commented. > > > int Isdiferent=0; > > Please follow the Java naming conventions: 'isDifferent'. > > > int treshold =50; > > Java naming conventions would suggest 'threshold' for this variable name. > > > for (int x=0; x<data.length; x=+200) > > Well, if somehow 'dataOld' was not 'null' and was empty, you got nothing > here. > > > { > > if(Math.abs(data[x] - dataOld[x]) <= treshold ) > > { > > Isdiferent +=1; > > You could also use the unary increment operator here. > > > } > > > float precentage = Isdiferent / data.length; > > The Java naming conventions would suggest that this variable name be > 'percentage'. > > > if (precentage > 20 ) > > You should use '20.0' since you're comparing floating-point values. > > > > > > > > > > > { > > kamera.takePicture(null,null,this); > > } > > > } > > } > > > @Override > > public void surfaceChanged(SurfaceHolder holder, int format, int > h, int w) { > > kamera.startPreview(); > > } > > > @Override > > public void surfaceCreated(SurfaceHolder holder) { > > kamera=Camera.open(); > > > try > > { > > Camera.Parameters parameter = > > kamera.getParameters(); > > Naming conventions would suggest that this variable be named in the plural. > > > > if(this.getResources().getConfiguration().orientation != > > 'this' in front of a method call is just silliness. > > > Configuration.ORIENTATION_LANDSCAPE) > > { > > parameter.set("orientation","portrait"); > > kamera.setDisplayOrientation(90); > > } > > > else > > { > > parameter.set("orientation","landscape"); > > > kamera.setDisplayOrientation(0); > > } > > > kamera.setParameters(parameter); > > kamera.setPreviewDisplay(holder); > > } > > > catch(IOException e) > > { > > kamera.release(); > > Is this the best way to handle this exception? > > > > > } > > kamera.startPreview(); > > } > > > @Override > > public void surfaceDestroyed(SurfaceHolder holder) { > > kamera.stopPreview(); > > kamera.release(); > > > } > > > @Override > > public void onPictureTaken(byte[] data, Camera kamera) { > > What if either parameter is 'null'? > > > > > // TODO Auto-generated method stub > > You should remove these auto-generated comments. > > > Uri imageFileUri = > > getContentResolver().insert(Media.EXTERNAL_CONTENT_URI,new > > ContentValues()); > > try > > > { > > /*String sdcardStorage = > > Environment.getExternalStorageDirectory().toString(); > > imageFileUri=Uri.parse(sdcardStorage + "/HeryMD/Test.jpg");*/ > > Don't include superfluous comments in forum posts. > > > String sdcardStorage = > > Environment.getExternalStorageDirectory().toString(); > > File f = new File(sdcardStorage > > + "/HeryMD/Test.jpg");> OutputStream > os = new > > FileOutputStream(f); > > > os.write(data); > > os.flush(); > > os.close(); > > You need to guarantee that the 'flush()' and 'close()' calls occur, which > you have not done. > > > } catch(FileNotFoundException e) > > { > > Toast t = > > Toast.makeText(this,e.getMessage(),> Toast.LENGTH_SHORT); > > t.show(); > > } > > > catch(IOException e) > > { > > Toast t = > > Toast.makeText(this,e.getMessage(), > > >Toast.LENGTH_SHORT); > > t.show(); > > } > > > kamera.startPreview(); > > } > > } > > -- > Lew -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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