Mega Code Archive
Backup Activity
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package app.test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import android.app.Activity;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.widget.Toast;
class BackupTask extends AsyncTask<String,Void,Integer> {
public interface CompletionListener {
void onBackupComplete();
void onRestoreComplete();
void onError(int errorCode);
}
public static final int BACKUP_SUCCESS = 1;
public static final int RESTORE_SUCCESS = 2;
public static final int BACKUP_ERROR = 3;
public static final int RESTORE_NOFILEERROR = 4;
public static final String COMMAND_BACKUP = "backupDatabase";
public static final String COMMAND_RESTORE = "restoreDatabase";
private Context mContext;
private CompletionListener listener;
public BackupTask(Context context) {
super();
mContext = context;
}
public void setCompletionListener(CompletionListener aListener) {
listener = aListener;
}
@Override
protected Integer doInBackground(String... params) {
File dbFile = mContext.getDatabasePath("mydb");
File exportDir = new File(Environment.getExternalStorageDirectory(), "myAppBackups");
if (!exportDir.exists()) {
exportDir.mkdirs();
}
File backup = new File(exportDir, dbFile.getName());
String command = params[0];
if(command.equals(COMMAND_BACKUP)) {
try {
backup.createNewFile();
fileCopy(dbFile, backup);
return BACKUP_SUCCESS;
} catch (IOException e) {
return BACKUP_ERROR;
}
} else if(command.equals(COMMAND_RESTORE)) {
try {
if(!backup.exists()) {
return RESTORE_NOFILEERROR;
}
dbFile.createNewFile();
fileCopy(backup, dbFile);
return RESTORE_SUCCESS;
} catch (IOException e) {
return BACKUP_ERROR;
}
} else {
return BACKUP_ERROR;
}
}
@Override
protected void onPostExecute(Integer result) {
switch(result) {
case BACKUP_SUCCESS:
if(listener != null) {
listener.onBackupComplete();
}
break;
case RESTORE_SUCCESS:
if(listener != null) {
listener.onRestoreComplete();
}
break;
case RESTORE_NOFILEERROR:
if(listener != null) {
listener.onError(RESTORE_NOFILEERROR);
}
break;
default:
if(listener != null) {
listener.onError(BACKUP_ERROR);
}
}
}
private void fileCopy(File source, File dest) throws IOException {
FileChannel inChannel = new FileInputStream(source).getChannel();
FileChannel outChannel = new FileOutputStream(dest).getChannel();
try {
inChannel.transferTo(0, inChannel.size(), outChannel);
} finally {
if (inChannel != null)
inChannel.close();
if (outChannel != null)
outChannel.close();
}
}
}
public class Test extends Activity implements BackupTask.CompletionListener {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SQLiteDatabase db = openOrCreateDatabase("mydb", Activity.MODE_PRIVATE, null);
db.close();
}
@Override
public void onResume() {
super.onResume();
if( Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) ) {
BackupTask task = new BackupTask(this);
task.setCompletionListener(this);
task.execute(BackupTask.COMMAND_RESTORE);
}
}
@Override
public void onPause() {
super.onPause();
if( Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) ) {
BackupTask task = new BackupTask(this);
task.execute(BackupTask.COMMAND_BACKUP);
}
}
@Override
public void onBackupComplete() {
Toast.makeText(this, "Backup Successful", Toast.LENGTH_SHORT).show();
}
@Override
public void onError(int errorCode) {
if(errorCode == BackupTask.RESTORE_NOFILEERROR) {
Toast.makeText(this, "No Backup to Restore", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Error: "+errorCode, Toast.LENGTH_SHORT).show();
}
}
@Override
public void onRestoreComplete() {
Toast.makeText(this, "Restore Successful", Toast.LENGTH_SHORT).show();
}
}
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