Java tutorial
/* * Copyright (C) 2012 The Serval Project * * This file is part of the Serval Maps Software * * Serval Maps Software is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * This source code is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this source code; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package org.servalproject.maps.export; import java.io.BufferedWriter; import java.io.FileNotFoundException; import java.io.FileWriter; import java.io.IOException; import java.util.Arrays; import org.apache.commons.csv.CSVFormat; import org.apache.commons.csv.CSVPrinter; import org.servalproject.maps.R; import org.servalproject.maps.provider.LocationsContract; import org.servalproject.maps.provider.PointsOfInterestContract; import org.servalproject.maps.utils.FileUtils; import org.servalproject.maps.utils.TimeUtils; import android.app.Activity; import android.app.AlertDialog; import android.content.ContentResolver; import android.content.DialogInterface; import android.database.Cursor; import android.os.AsyncTask; import android.os.Environment; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.ProgressBar; import android.widget.TextView; /** * class to undertake an async task to export in binary format */ public class CsvAsyncTask extends AsyncTask<String, Integer, Integer> { /* * private class level constants */ private final boolean V_LOG = false; private final String TAG = "CsvExportTask"; /* * private class level variables */ private ProgressBar progressBar; private TextView progressLabel; private Activity context; private boolean updateUI = true; private boolean updateForLocation = false; private boolean updateForPoi = false; private CSVFormat csvFormat; private Integer recordCount = -1; public CsvAsyncTask(Activity context, ProgressBar progressBar, TextView progressLabel) { // check the parameters if (context == null || progressBar == null || progressLabel == null) { throw new IllegalArgumentException("all parameters are required"); } this.context = context; this.progressBar = progressBar; this.progressLabel = progressLabel; this.csvFormat = CSVFormat.DEFAULT; csvFormat.withEscape('\\'); csvFormat.withCommentStart('#'); if (V_LOG) { Log.v(TAG, "class instantiated"); } } /* * (non-Javadoc) * @see android.os.AsyncTask#onPreExecute() */ @Override protected void onPreExecute() { if (V_LOG) { Log.v(TAG, "onPreExecute called"); } progressLabel.setText(""); progressLabel.setVisibility(View.VISIBLE); progressBar.setVisibility(View.VISIBLE); Button mButton = (Button) context.findViewById(R.id.export_ui_btn_export); mButton.setEnabled(false); } /* * (non-Javadoc) * @see android.os.AsyncTask#onProgressUpdate(Progress[]) */ @Override protected void onProgressUpdate(Integer... progress) { if (V_LOG) { Log.v(TAG, "onProgressUpdate called: " + progress[0].toString()); } // update the progress bar super.onProgressUpdate(progress[0]); progressBar.setProgress(progress[0]); if (updateUI) { if (updateForLocation) { progressLabel.setText(R.string.export_ui_progress_location); updateForLocation = false; updateUI = false; } if (updateForPoi) { progressLabel.setText(R.string.export_ui_progress_poi); updateForPoi = false; updateUI = false; } } } /* * (non-Javadoc) * @see android.os.AsyncTask#onPostExecute(java.lang.Object) */ @Override protected void onPostExecute(Integer result) { if (V_LOG) { Log.v(TAG, "onPostExecute called: "); } // finalse the results progressBar.setVisibility(View.INVISIBLE); progressBar.setProgress(0); progressLabel.setVisibility(View.INVISIBLE); Button mButton = (Button) context.findViewById(R.id.export_ui_btn_export); mButton.setEnabled(true); String mMessage = String.format(context.getString(R.string.export_ui_finished_msg), recordCount, context.getString(R.string.system_path_export_data)); AlertDialog.Builder mBuilder = new AlertDialog.Builder(context); mBuilder.setMessage(mMessage).setCancelable(false).setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { dialog.cancel(); } }); AlertDialog mAlert = mBuilder.create(); mAlert.show(); } /* * (non-Javadoc) * @see android.os.AsyncTask#doInBackground(Params[]) */ @Override protected Integer doInBackground(String... taskType) { if (V_LOG) { Log.v(TAG, "doInBackground called: " + taskType[0]); } // determine which export task to undertake if (taskType[0].equals("All Data") == true) { recordCount = doAllExport(); } else if (taskType[0].equals("All Location Records") == true) { recordCount = doLocationExport(); } else { recordCount = doPoiExport(); } return recordCount; } // private method to undertake all exports private Integer doAllExport() { if (V_LOG) { Log.v(TAG, "doAllExport called: "); } Integer recordCount = doLocationExport(); recordCount += doPoiExport(); return recordCount; } // private method to undertake a location export private Integer doLocationExport() { if (V_LOG) { Log.v(TAG, "doLocationExport called: "); } // reset the progress bar progressBar.setProgress(0); Integer mRecordCount = 0; updateUI = true; updateForLocation = true; // get all of the location data ContentResolver mContentResolver = context.getApplicationContext().getContentResolver(); // get the content Cursor mCursor = mContentResolver.query(LocationsContract.CONTENT_URI, null, null, null, null); // check on what was returned if (mCursor.getCount() > 0) { progressBar.setMax(mCursor.getCount()); mRecordCount = mCursor.getCount(); // get the export directory // get the path for the output files String mOutputPath = Environment.getExternalStorageDirectory().getPath(); mOutputPath += context.getString(R.string.system_path_export_data); if (FileUtils.isDirectoryWritable(mOutputPath) == false) { Log.e(TAG, "unable to access the required output directory"); mCursor.close(); return 0; } // build the output file name String mFileName = "serval-maps-export-locations-" + TimeUtils.getToday() + ".csv"; // write the data to the file BufferedWriter mOutput = null; String[] mLine = new String[LocationsContract.Table.COLUMNS.length]; try { //mOutput = new BufferedOutputStream(new FileOutputStream(mOutputPath + mFileName, false)); mOutput = new BufferedWriter(new FileWriter(mOutputPath + mFileName, false)); CSVPrinter mPrinter = new CSVPrinter(mOutput, csvFormat); // write the comment line mPrinter.printComment("Location data sourced from the Serval Maps application"); mPrinter.printComment("File created: " + TimeUtils.getToday()); mPrinter.printComment(Arrays.toString(LocationsContract.Table.COLUMNS)); while (mCursor.moveToNext()) { for (int i = 0; i < LocationsContract.Table.COLUMNS.length; i++) { mLine[i] = mCursor.getString(mCursor.getColumnIndex(LocationsContract.Table.COLUMNS[i])); } mPrinter.println(mLine); publishProgress(mCursor.getPosition()); // check to see if we need to cancel this task if (isCancelled() == true) { break; } } } catch (FileNotFoundException e) { Log.e(TAG, "unable to open the output file", e); } catch (IOException e) { Log.e(TAG, "unable to write the message at '" + mCursor.getPosition() + "' in the cursor", e); } finally { // play nice and tidy up try { if (mOutput != null) { mOutput.close(); } } catch (IOException e) { Log.e(TAG, "unable to close the output file", e); } mCursor.close(); } } return mRecordCount; } // private method to undetake a POI export private Integer doPoiExport() { // reset the progress bar progressBar.setProgress(0); Integer mRecordCount = 0; updateUI = true; updateForPoi = true; if (V_LOG) { Log.v(TAG, "doPoiExport called: "); } // get all of the location data ContentResolver mContentResolver = context.getApplicationContext().getContentResolver(); // get the content Cursor mCursor = mContentResolver.query(PointsOfInterestContract.CONTENT_URI, null, null, null, null); // check on what was returned if (mCursor.getCount() > 0) { progressBar.setMax(mCursor.getCount()); mRecordCount = mCursor.getCount(); // get the export directory // get the path for the output files String mOutputPath = Environment.getExternalStorageDirectory().getPath(); mOutputPath += context.getString(R.string.system_path_export_data); if (FileUtils.isDirectoryWritable(mOutputPath) == false) { Log.e(TAG, "unable to access the required output directory"); mCursor.close(); return 0; } // build the output file name String mFileName = "serval-maps-export-pois-" + TimeUtils.getToday() + ".csv"; // write the data to the file BufferedWriter mOutput = null; String[] mLine = new String[PointsOfInterestContract.Table.COLUMNS.length]; try { //mOutput = new BufferedOutputStream(new FileOutputStream(mOutputPath + mFileName, false)); mOutput = new BufferedWriter(new FileWriter(mOutputPath + mFileName, false)); CSVPrinter mPrinter = new CSVPrinter(mOutput, csvFormat); // write the comment line mPrinter.printComment("Location data sourced from the Serval Maps application"); mPrinter.printComment("File created: " + TimeUtils.getToday()); mPrinter.printComment(Arrays.toString(PointsOfInterestContract.Table.COLUMNS)); while (mCursor.moveToNext()) { for (int i = 0; i < PointsOfInterestContract.Table.COLUMNS.length; i++) { mLine[i] = mCursor .getString(mCursor.getColumnIndex(PointsOfInterestContract.Table.COLUMNS[i])); } mPrinter.println(mLine); publishProgress(mCursor.getPosition()); // check to see if we need to cancel this task if (isCancelled() == true) { break; } } } catch (FileNotFoundException e) { Log.e(TAG, "unable to open the output file", e); } catch (IOException e) { Log.e(TAG, "unable to write the message at '" + mCursor.getPosition() + "' in the cursor", e); } finally { // play nice and tidy up try { if (mOutput != null) { mOutput.close(); } } catch (IOException e) { Log.e(TAG, "unable to close the output file", e); } mCursor.close(); } } return mRecordCount; } }