Android Open Source - T-CEP-Alert Cached Alert Data

From Project

Back to project page T-CEP-Alert.
License

The source code is released under:
MIT License
If you think the Android project T-CEP-Alert listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.
Java Source Code

package org.ruscoe.tcepalert.dao;
//from  ww  w. j av a 2 s.c o  m
import java.util.ArrayList;
import java.util.List;

import org.ruscoe.tcepalert.constants.Constants;
import org.ruscoe.tcepalert.models.Alert;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

/**
 * Extends the game Data Access Object to provide access to cached
 * alerts data.
 * 
 * Alerts are cached to be displayed while the latest alerts are 
 * being retrieved from the server. This is also useful when the user
 * has lost their network connection and wants to read a previously loaded
 * alert.
 * 
 * @author Dan Ruscoe
 */
public class CachedAlertData extends AlertDAO
{
  public static final String TABLE_NAME = "cachedAlertData";
  
  public static final String ALERT_ID = "alertId";
  public static final String TITLE = "title";
  public static final String FIRST_POSTED_DATE = "firstPostedDate";
  public static final String LAST_UPDATED_DATE = "lastUpdatedDate";
  public static final String MESSAGE = "message";
  public static final String CREATED_TIMESTAMP = "createdTimestamp";
  public static final String UPDATED_TIMESTAMP = "updatedTimestamp";
  
  /**
   * These constants indicate the locations of the database table
   * fields in a instance of Cursor returned by a database query.
   * 
   * @see getCachedAlertData for use.
   */
  public static final int FIELD_POS_ALERT_ID = 0;
  public static final int FIELD_POS_TITLE = 1;
  public static final int FIELD_POS_FIRST_POSTED_DATE = 2;
  public static final int FIELD_POS_LAST_UPDATED_DATE = 3;
  public static final int FIELD_POS_MESSAGE = 4;
  public static final int FIELD_POS_CREATED_TIMESTAMP = 5;
  public static final int FIELD_POS_UPDATED_TIMESTAMP = 6;
  
  public CachedAlertData(Context ctx)
  {
    super(ctx);
  }
  
  /**
   * Gets a list of locally cached alerts as instances of Alert.
   * 
   * @return List<Alert> - Locally cached alerts.
   */
  public List<Alert> getCachedAlerts()
  {
      SQLiteDatabase db = this.getReadableDatabase();
      
      String[] from = { ALERT_ID, TITLE, FIRST_POSTED_DATE, LAST_UPDATED_DATE, MESSAGE, CREATED_TIMESTAMP, UPDATED_TIMESTAMP };
      Cursor cursor = db.query(TABLE_NAME, from, null, null, null, null, null);
      
      List<Alert> cachedAlerts = new ArrayList<Alert>();
      
      Alert alert = null;
      
      if (cursor != null)
      {
        while (cursor.moveToNext())
          {
          alert = new Alert();
          
          alert.setAlertId(cursor.getString(FIELD_POS_ALERT_ID));
          alert.setTitle(cursor.getString(FIELD_POS_TITLE));
          alert.setFirstPostedDate(cursor.getString(FIELD_POS_FIRST_POSTED_DATE));
          alert.setLastUpdatedDate(cursor.getString(FIELD_POS_LAST_UPDATED_DATE));
          alert.setMessage(cursor.getString(FIELD_POS_MESSAGE));
          alert.setCreatedTimestamp(cursor.getLong(FIELD_POS_CREATED_TIMESTAMP));
          alert.setUpdatedTimestamp(cursor.getLong(FIELD_POS_UPDATED_TIMESTAMP));
          
          cachedAlerts.add(alert);
          }
        cursor.close();
      }
      
      db.close();
      
      return cachedAlerts;
  }
  
  /**
   * Caches a list of Alert instances in the database.
   * 
   * @param List<Alert> alerts - The Alert instances to cache.
   */
    public void cacheAlerts(List<Alert> alerts)
    {
      if (alerts != null)
      {
        for (int i = 0; i <= (alerts.size() - 1); i++)
        {
          cacheAlert(alerts.get(i));
        }
      }
    }
  
    /**
     * Caches a single Alert instance in the database.
     * 
     * @param Alert alert - The Alert instance to cache.
     */
  public void cacheAlert(Alert alert)
  {
    if (alert.getAlertId() == null || alert.getAlertId().equals(""))
    {
      Log.w(Constants.APP_LOG_NAME, "Attempted to cached Alert with null or empty alertId.");
      return;
    }
    
      SQLiteDatabase db = this.getWritableDatabase();
      
      ContentValues values = new ContentValues();
      
      values.put(TITLE, alert.getTitle());
      values.put(FIRST_POSTED_DATE, alert.getFirstPostedDate());
      values.put(LAST_UPDATED_DATE, alert.getLastUpdatedDate());
      values.put(MESSAGE, alert.getMessage());
      values.put(CREATED_TIMESTAMP, alert.getCreatedTimestamp());
      values.put(UPDATED_TIMESTAMP, alert.getUpdatedTimestamp());
      
      int affectedRows = db.update(TABLE_NAME, values, ALERT_ID + "='" + alert.getAlertId() + "'", null);
      
      if (affectedRows < 1)
      {
        values.put(ALERT_ID, alert.getAlertId());
        
        db.insertOrThrow(TABLE_NAME, null, values);
      }
      
      db.close();
  }
  
  /**
   * Clears all cached alerts by emptying the database table.
   */
  public void clearCachedAlerts()
  {
    SQLiteDatabase db = this.getWritableDatabase();
    
    db.execSQL("DELETE FROM " + TABLE_NAME);
  }
}
Java Source Code List
