Android Open Source - SimpleAndroidChat D B Model

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License

The source code is released under:

GNU General Public License

Java Source Code

package com.anderscore.simpleandroidchat;
//www  .  j a  v  a 2  s. com
import java.util.ArrayList;

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


/** Speichert und ldt Contact- und MessageData in und aus der Datenbank
 *   
 *   @author paloka
 */
class DBModel{

  private DBConnection db;


  /**  Initialisiert das ContactModel
   * 
   *   @param context - Anwendungskontext
   */
  DBModel(Context context){
    this.db      = DBConnection.getDBConnection(context);
  }
  
  
/* ------- Interface ------- */

  
  /**  Gibt alle in der DB stehenden Contacte zurck.
   *  
   *  @return ArrayList<Contact> - Alle Contacts einsortiert mit der userId.
   */
  ArrayList<Contact> getContacts(){
    SQLiteDatabase db    = this.db.getReadableDatabase();
    
    String sql  =   "SELECT * FROM " + 
            Constants.DB.Contacts.TABLE_NAME + " ORDER BY " + 
            Constants.DB.Contacts.USER + " ASC";
    Cursor cursor = db.rawQuery(sql, null);
    
    ArrayList<Contact> contacts = new ArrayList<Contact>();
    if(!cursor.moveToFirst())  return contacts;
    do{
      boolean  online      =  false;
      if(cursor.getInt(cursor.getColumnIndex(Constants.DB.Contacts.ONLINE)) == 1)  online = true;
      
      contacts.add(new Contact(  cursor.getInt(cursor.getColumnIndex(Constants.DB.Contacts.ID)), 
                    cursor.getString(cursor.getColumnIndex(Constants.DB.Contacts.USER)), 
                    online,
                    null));
      cursor.moveToNext();
    }while(!cursor.isAfterLast());
    return contacts;
  }
  
  
  /**  Gibt einen contact zurck.
   *   
   *   @param contactId
   *   @return - Den gewnschten Contact oder null
   */
  Contact getContact(int contactId){
    SQLiteDatabase db  = this.db.getReadableDatabase();
    String sql  =  "SELECT * " +
            "FROM " + Constants.DB.Contacts.TABLE_NAME + " AS C " +
            "LEFT JOIN " + Constants.DB.Messages.TABLE_NAME + " AS M " +
            "ON C." + Constants.DB.Contacts.ID + " = M." + Constants.DB.Messages.USER_ID +
            " WHERE C." + Constants.DB.Contacts.ID + " = " + contactId +
            " ORDER BY M." + Constants.DB.Contacts.ID + " ASC";
    Cursor cursor = db.rawQuery(sql, null);
    
    if(!cursor.moveToFirst())  return null;
    String   user      =  cursor.getString(cursor.getColumnIndex(Constants.DB.Contacts.USER));
    boolean  online      =  false;
    if(cursor.getInt(cursor.getColumnIndex(Constants.DB.Contacts.ONLINE)) == 1)  online = true;
    
    ArrayList<ChatMsg> chatHistory  = new ArrayList<ChatMsg>();
    if(!cursor.isNull(cursor.getColumnIndex(Constants.DB.Messages.TEXT_MSG))){
      do{
        int id        = cursor.getInt(cursor.getColumnIndex(Constants.DB.Messages.ID));
        boolean direction  = false;
        if(cursor.getInt(cursor.getColumnIndex(Constants.DB.Messages.INCOMMING))==1)  direction = true;
        String  msg      = cursor.getString(cursor.getColumnIndex(Constants.DB.Messages.TEXT_MSG));
        ChatMsg chatMsg    = new ChatMsg(id,user,contactId,direction,msg);
        chatHistory.add(chatMsg);
        cursor.moveToNext();
      }while(!cursor.isAfterLast());
    }
    return new Contact(contactId, user, online, chatHistory);
  }
  
  
  /**  Versucht den Contact zu editieren. Gibt es keinen solchen Contact wird ein neuer Contact angelegt.
   *   
   *   @param contact - hinzuzufgender Contact.
   *  @return contact
   */
  Contact addOrEditContact(Contact contact){  
    SQLiteDatabase db  = this.db.getWritableDatabase();
    
    ContentValues values  =   new ContentValues();
    int online  = 0;
    if(contact.isOnline())  online = 1;
    values.put(Constants.DB.Contacts.ONLINE, online);
    
    String selection    =   Constants.DB.Contacts.USER + " = ?";
    String[] selectionArgs  =   {contact.getUser()};
    
    if(db.update(Constants.DB.Contacts.TABLE_NAME,values,selection,selectionArgs) > 0){
      String sql  =   "SELECT * " +
              "FROM " + Constants.DB.Contacts.TABLE_NAME + " AS C " +
              "LEFT JOIN " + Constants.DB.Messages.TABLE_NAME + " AS M " +
              "ON C." + Constants.DB.Contacts.ID + " = M." + Constants.DB.Messages.USER_ID +
              " WHERE C." + Constants.DB.Contacts.USER + " = ?";
      Cursor cursor  = db.rawQuery(sql, selectionArgs);
      cursor.moveToFirst();
      contact.setId(cursor.getInt(0));  //Da DB_CONTACT_ID = DB_MESSAGE_ID hier Zugriff ?ber Index
      
      ArrayList<ChatMsg> chatHistory  = new ArrayList<ChatMsg>();
      if(!cursor.isNull(cursor.getColumnIndex(Constants.DB.Messages.TEXT_MSG))){
        do{
          int id        = cursor.getInt(cursor.getColumnIndex(Constants.DB.Messages.ID));
          boolean direction  = false;
          if(cursor.getInt(cursor.getColumnIndex(Constants.DB.Messages.INCOMMING))==1)  direction = true;;
          String  msg      = cursor.getString(cursor.getColumnIndex(Constants.DB.Messages.TEXT_MSG));
          ChatMsg chatMsg    = new ChatMsg(id,contact.getUser(),contact.getId(),direction,msg);
          chatHistory.add(chatMsg);
          cursor.moveToNext();
        }while(!cursor.isAfterLast());
      }
      contact.setChatHistory(chatHistory);
    } else {
      values.put(Constants.DB.Contacts.USER, contact.getUser());
      values.put(Constants.DB.Contacts.ONLINE, contact.isOnline());
      contact.setId((int)db.insert(Constants.DB.Contacts.TABLE_NAME, null, values));
      contact.setChatHistory(new ArrayList<ChatMsg>());
    }
    return contact;
  }
  
  
  /** Fgt einem Contact eine Nachricht im Chatverlauf hinzu.
   *  
   *  @param chatMsg - hinzuzufgende Nachricht.
   */
  ChatMsg appendChatMsg(ChatMsg chatMsg){
    SQLiteDatabase db  = this.db.getWritableDatabase();
    if(chatMsg.isIncomming()==true){
      String sql    =   "SELECT * " +
                "FROM " + Constants.DB.Contacts.TABLE_NAME +
                " WHERE " + Constants.DB.Contacts.USER + " = ?";
      String[] selectionArgs  = {chatMsg.getUser()};
      Cursor cursor  =  db.rawQuery(sql, selectionArgs);
      if(cursor.moveToFirst()){
        chatMsg.setUserId(cursor.getInt(cursor.getColumnIndex(Constants.DB.Contacts.ID)));
      }
    }
    ContentValues values  = new ContentValues();
    values.put(Constants.DB.Messages.USER_ID, chatMsg.getUserId());
    if(chatMsg.isIncomming())  values.put(Constants.DB.Messages.INCOMMING, 1);
    else            values.put(Constants.DB.Messages.INCOMMING, 0);
    values.put(Constants.DB.Messages.TEXT_MSG, chatMsg.getMsg());
    int messageId = (int) db.insert(Constants.DB.Messages.TABLE_NAME, null, values);
    chatMsg.setId(messageId);
    return chatMsg;
  }
}

Java Source Code List

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