android writing log statements to sdcard

Question

I'm trying to write log statements to the sdcard. The way i have decided to do it is create a file on the sdcard through the Application Object. This way i can call a static method logToSdcard() from anywhere in the app.

The containing folder "/RR3log/" is created but every statement that i log is in its own file called "rr3LogFile.txt". So i have multiple rr3LogFile files containing one staement in each.

How can i write all statement to one rr3LogFile file? Thanks in advance Matt.

public class NfcScannerApplication extends Application{

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




        File storageDir = new File(Environment
                .getExternalStorageDirectory(), "/RR3log/");


        storageDir.mkdir();
        try {

            if(outfile == null){
            outfile=File.createTempFile("rr3LogFile", ".txt",storageDir);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }





public static void logToSdcard(String tag, String statement){


        Log.e(TAG, "inside logtosdcard$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");


                String state = android.os.Environment.getExternalStorageState();
                if(!state.equals(android.os.Environment.MEDIA_MOUNTED))  {
                    try {
                        throw new IOException("SD Card is not mounted.  It is " + state + ".");
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

                DateTime now = new DateTime();
                DateTimeFormatter fmt = DateTimeFormat.forPattern("d-MMM-Y H:mm");
                String dateStr = fmt.print(now);


                try{


                    FileOutputStream fOut = new FileOutputStream(outfile);
                    OutputStreamWriter myOutWriter =new OutputStreamWriter(fOut);
                    myOutWriter.append(dateStr + " " + tag + "     ");
                    myOutWriter.append(statement);
                    myOutWriter.append("\n");
                    myOutWriter.flush();
                    myOutWriter.close();
                    fOut.close();

                }catch(IOException e){
                    e.printStackTrace();
                }




    }


}

.

Then in an Activity anywhere in the app.

@Override
    protected void onResume() {
        super.onResume();
        Log.e(TAG, "inside entryactivity onResume");
        NfcScannerApplication.logToSdcard(TAG, "inside entryactivity onResume" );

Answer 1

In your logToSdcard Method create the FileOutputStream with an additional parameter:

FileOutputStream fOut = new FileOutputStream(outfile, true);

The true paramters says that contents will be appended to the file. See also FileOutputStream

Answer 2

Try that:

public static void printLog(Context context){
    String filename = context.getExternalFilesDir(null).getPath() + File.separator + "my_app.log";
    String command = "logcat -f "+ filename + " -v time -d *:V";

    Log.d(TAG, "command: " + command);

    try{
        Runtime.getRuntime().exec(command);
    }
    catch(IOException e){
        e.printStackTrace();
    }
}

The logs will be saved continuously until the application is exited.