Android Open Source - android-rss R S S Reader Provider

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License

The source code is released under:
GNU General Public License
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Java Source Code

/* 
 * $Id: RSSReaderProvider.java 114 2008-02-14 05:09:23Z jasta00 $
 *//  www  . j  a v a2s  . c om
 * Copyright (C) 2007 Josh Guilfoyle <jasta@devtcg.org>
 *
 * This program 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 2, or (at your option) any
 * later version.
 *
 * This program 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.
 */

package org.devtcg.rssreader.provider;


import org.devtcg.rssreader.provider.RSSReaderProvider;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;

import org.devtcg.rssreader.R;

import android.content.ContentProvider;
import android.database.sqlite.SQLiteOpenHelper;
import android.content.ContentUris;
import android.content.UriMatcher;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteQueryBuilder;
import android.content.Resources;
import android.database.ArrayListCursor;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.ParcelFileDescriptor;
import android.text.TextUtils;
import android.util.Log;

public class RSSReaderProvider extends ContentProvider
{
  private SQLiteDatabase mDB;
  
  private static final String TAG = "RSSReaderProvider";
  private static final String DATABASE_NAME = "rss_reader.db";
  private static final int DATABASE_VERSION = 9;

  private static HashMap<String, String> CHANNEL_LIST_PROJECTION_MAP;
  private static HashMap<String, String> POST_LIST_PROJECTION_MAP;

  private static final int CHANNELS = 1;
  private static final int CHANNEL_ID = 2;
  private static final int POSTS = 3;
  private static final int POST_ID = 4;
  private static final int CHANNEL_POSTS = 5;
  private static final int CHANNELICON_ID = 6;

  private static final UriMatcher URL_MATCHER;

  private static class DatabaseHelper extends SQLiteOpenHelper
  {
    protected void onCreateChannels(SQLiteDatabase db)
    {
      db.execSQL("CREATE TABLE rssreader_channel (_id INTEGER PRIMARY KEY," +
             "  title TEXT UNIQUE, url TEXT UNIQUE, " +
             "    icon TEXT, icon_url TEXT, logo TEXT);");
    }

    protected void onCreatePosts(SQLiteDatabase db)
    {
      db.execSQL("CREATE TABLE rssreader_post (_id INTEGER PRIMARY KEY," +
                 "    channel_id INTEGER, title TEXT, url TEXT, " + 
                 "    posted_on DATETIME, body TEXT, author TEXT, read INTEGER(1) DEFAULT '0');");

      /* TODO: Should we narrow this more to just URL _or_ title? */
      db.execSQL("CREATE UNIQUE INDEX unq_post ON rssreader_post (title, url);");

      /* Create an index to efficiently access posts on a particular channel. */
      db.execSQL("CREATE INDEX idx_channel ON rssreader_post (channel_id);");
    }

    @Override
    public void onCreate(SQLiteDatabase db)
    {
      onCreateChannels(db);
      onCreatePosts(db);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
    {
      assert(newVersion == DATABASE_VERSION);
      Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion + "...");

      switch(oldVersion)
      {
      case 7:
        db.execSQL("ALTER TABLE rssreader_channel ADD COLUMN icon_url TEXT;");
        break;

      default:
        Log.w(TAG, "Version too old, wiping out database contents...");
        db.execSQL("DROP TABLE IF EXISTS rssreader_channel;");
        db.execSQL("DROP TABLE IF EXISTS rssreader_post;");
        onCreate(db);
        break;
      }
    }
  }
  
  @Override
  public boolean onCreate()
  {
    DatabaseHelper dbHelper = new DatabaseHelper();
    mDB = dbHelper.openDatabase(getContext(), DATABASE_NAME, null, DATABASE_VERSION);
    
    return (mDB == null) ? false : true;
  }
  
  @Override
  public Cursor query(Uri url, String[] projection, String selection,
    String[] selectionArgs, String sort)
  {
    SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
    
    String defaultSort = null;
    
    switch(URL_MATCHER.match(url))
    {
    case CHANNELS:
      qb.setTables("rssreader_channel");
      qb.setProjectionMap(CHANNEL_LIST_PROJECTION_MAP);
      defaultSort = RSSReader.Channels.DEFAULT_SORT_ORDER;
      break;

    case CHANNEL_ID:
      qb.setTables("rssreader_channel");
      qb.appendWhere("_id=" + url.getPathSegments().get(1));
      break;

      /*
    case POSTS:
      qb.setTables("rssreader_post");
      qb.setProjectionMap(POST_LIST_PROJECTION_MAP);
      defaultSort = RSSReader.Posts.DEFAULT_SORT_ORDER;
      break;
      */
    case CHANNEL_POSTS:
      qb.setTables("rssreader_post");
      qb.appendWhere("channel_id=" + url.getPathSegments().get(1));
      qb.setProjectionMap(POST_LIST_PROJECTION_MAP);
      defaultSort = RSSReader.Posts.DEFAULT_SORT_ORDER;
      break;
      
    case POST_ID:
      qb.setTables("rssreader_post");
      qb.appendWhere("_id=" + url.getPathSegments().get(1));
      break;
      
    default:
      throw new IllegalArgumentException("Unknown URL " + url);
    }
    
    String orderBy;

    if (TextUtils.isEmpty(sort))
      orderBy = defaultSort;
    else
      orderBy = sort;

    Cursor c = qb.query(mDB, projection, selection, selectionArgs,
        null, null, orderBy);

    c.setNotificationUri(getContext().getContentResolver(), url);
    
    return c;
  }

  @Override
  public String getType(Uri url)
  {
    switch(URL_MATCHER.match(url))
    {
    case CHANNELS:
      return "vnd.android.cursor.dir/vnd.rssreader.channel";
    case CHANNEL_ID:
      return "vnd.android.cursor.item/vnd.rssreader.channel";
    case CHANNELICON_ID:
      return "image/x-icon";
    case POSTS:
    case CHANNEL_POSTS:
      return "vnd.android.cursor.dir/vnd.rssreader.post";
    case POST_ID:
      return "vnd.android.cursor.item/vnd.rssreader.post";
    default:
      throw new IllegalArgumentException("Unknown URL " + url);
    }
  }
  
  private String getIconFilename(long channelId)
  {
    return "channel" + channelId + ".ico";
  }

  private String getIconPath(long channelId)
  {
    return getContext().getFileStreamPath(getIconFilename(channelId)).getAbsolutePath();
  }
  
  private void copyDefaultIcon(String path)
    throws FileNotFoundException, IOException
  {
    FileOutputStream out = new FileOutputStream(path);

    InputStream ico =
      getContext().getResources().openRawResource(R.drawable.feedicon);

    byte[] buf = new byte[1024];
    int n;

    while ((n = ico.read(buf)) != -1)
      out.write(buf, 0, n);
    
    ico.close();
    
    out.close();
  }
  
  public ParcelFileDescriptor openFile(Uri uri, String mode)
    throws FileNotFoundException
  {
    switch(URL_MATCHER.match(uri))
    {
    case CHANNELICON_ID:
      long id = Long.valueOf(uri.getPathSegments().get(1));
      String path = getIconPath(id);

      /* XXX: This appears to be an Android bug: files created with
       * ParcelFileDescriptor.MODE_CREATE have mode 0, which is not
       * readable. */
      if (mode.equals("rw") == true)
      {
        FileOutputStream foo = getContext().openFileOutput(getIconFilename(id), 0);
        
        try { foo.write(new byte[] { 't' }); foo.close(); }
        catch (Exception e) { }
      }

      File file = new File(path);
      int modeint;
      
      if (mode.equals("rw") == true)
      {
        modeint = ParcelFileDescriptor.MODE_READ_WRITE |
          ParcelFileDescriptor.MODE_TRUNCATE;
      }
      else
      {
        modeint = ParcelFileDescriptor.MODE_READ;
        
        if (file.exists() == false)
        {
          try
          {
            /* TODO: Find a way around this.  We should be able to
             * simply return an InputStream. */
            copyDefaultIcon(path);
          }
          catch(IOException e)
          {
            Log.d(TAG, "Unable to create default feed icon", e);
            return null;
          }          
        }
      }
      
      return ParcelFileDescriptor.open(file, modeint);
    default:
      throw new IllegalArgumentException("Unknown URL " + uri);
    }
  }
  
  private long insertChannels(ContentValues values)
  {
    Resources r = Resources.getSystem();

    /* TODO: This validation sucks. */
    if (values.containsKey(RSSReader.Channels.TITLE) == false)
      values.put(RSSReader.Channels.TITLE, r.getString(android.R.string.untitled));

    long id = mDB.insert("rssreader_channel", "title", values);

    if (values.containsKey(RSSReader.Channels.ICON) == false)
    {
      Uri iconUri;

      iconUri = RSSReader.Channels.CONTENT_URI.buildUpon()
        .appendPath(String.valueOf(id))
        .appendPath("icon")
        .build();

      /* LAME! */
      ContentValues update = new ContentValues();
      update.put(RSSReader.Channels.ICON, iconUri.toString());
      mDB.update("rssreader_channel", update, "_id=" + id, null);
    }

    return id;
  }

  private long insertPosts(ContentValues values)
  {
    /* TODO: Validation? */
    return mDB.insert("rssreader_post", "title", values);
  }

  @Override
  public Uri insert(Uri url, ContentValues initialValues)
  {
    long rowID;
    ContentValues values;

    if (initialValues != null)
      values = new ContentValues(initialValues);
    else
      values = new ContentValues();
    
    Uri uri;
    
    if (URL_MATCHER.match(url) == CHANNELS)
    {
      rowID = insertChannels(values);
      uri = ContentUris.withAppendedId(RSSReader.Channels.CONTENT_URI, rowID);
    }
    else if (URL_MATCHER.match(url) == POSTS)
    {
      rowID = insertPosts(values);
      uri = ContentUris.withAppendedId(RSSReader.Posts.CONTENT_URI, rowID);
    }
    else
    {
      throw new IllegalArgumentException("Unknown URL " + url);
    }
    
    if (rowID > 0)
    {
      assert(uri != null);
      getContext().getContentResolver().notifyChange(uri, null);
      return uri;
    }
    
    throw new SQLException("Failed to insert row into " + url);
  }
  
  @Override
  public int delete(Uri url, String where, String[] whereArgs)
  {
    int count;
    String myWhere;
    
    switch (URL_MATCHER.match(url))
    {
    case CHANNELS:
      count = mDB.delete("rssreader_channel", where, whereArgs);
      break;
      
    case CHANNEL_ID:
      myWhere = "_id=" + url.getPathSegments().get(1) + (!TextUtils.isEmpty(where) ? " AND (" + where + ")" : "");      
      count = mDB.delete("rssreader_channel", myWhere, whereArgs);
      break;
      
    case POSTS:
      count = mDB.delete("rssreader_post", where, whereArgs);
      break;
      
    case POST_ID:
      myWhere = "_id=" + url.getPathSegments().get(1) + (!TextUtils.isEmpty(where) ? " AND (" + where + ")" : "");      
      count = mDB.delete("rssreader_post", myWhere, whereArgs);
      break;
      
    default:
      throw new IllegalArgumentException("Unknown URL " + url);
    }
    
    getContext().getContentResolver().notifyChange(url, null);
    return count;
  }
  
  @Override
  public int update(Uri url, ContentValues values, String where, String[] whereArgs)
  {
    int count;
    String myWhere;
    
    switch (URL_MATCHER.match(url))
    {
    case CHANNELS:
      count = mDB.update("rssreader_channel", values, where, whereArgs);
      break;
      
    case CHANNEL_ID:
      myWhere = "_id=" + url.getPathSegments().get(1) + (!TextUtils.isEmpty(where) ? " AND (" + where + ")" : "");      
      count = mDB.update("rssreader_channel", values, myWhere, whereArgs);
      break;
      
    case POSTS:
      count = mDB.update("rssreader_post", values, where, whereArgs);
      break;
      
    case POST_ID:
      myWhere = "_id=" + url.getPathSegments().get(1) + (!TextUtils.isEmpty(where) ? " AND (" + where + ")" : "");      
      count = mDB.update("rssreader_post", values, myWhere, whereArgs);
      break;
      
    default:
      throw new IllegalArgumentException("Unknown URL " + url);
    }
    
    getContext().getContentResolver().notifyChange(url, null);
    return count;
  }

  static
  {
    URL_MATCHER = new UriMatcher(UriMatcher.NO_MATCH);
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "channels", CHANNELS);
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "channels/#", CHANNEL_ID);
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "channels/#/icon", CHANNELICON_ID);
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "posts", POSTS);
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "posts/#", POST_ID);
    
    /* TODO: use channels/#/posts */
    URL_MATCHER.addURI(RSSReader.AUTHORITY, "postlist/#", CHANNEL_POSTS);

    CHANNEL_LIST_PROJECTION_MAP = new HashMap<String, String>();
    CHANNEL_LIST_PROJECTION_MAP.put(RSSReader.Channels._ID, "_id");
    CHANNEL_LIST_PROJECTION_MAP.put(RSSReader.Channels.TITLE, "title");
    CHANNEL_LIST_PROJECTION_MAP.put(RSSReader.Channels.URL, "url");
    CHANNEL_LIST_PROJECTION_MAP.put(RSSReader.Channels.ICON, "icon");
    CHANNEL_LIST_PROJECTION_MAP.put(RSSReader.Channels.LOGO, "logo");
    
    POST_LIST_PROJECTION_MAP = new HashMap<String, String>();
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts._ID, "_id");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.CHANNEL_ID, "channel_id");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.READ, "read");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.TITLE, "title");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.URL, "url");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.AUTHOR, "author");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.DATE, "posted_on");
    POST_LIST_PROJECTION_MAP.put(RSSReader.Posts.BODY, "body");
  }
}
Java Source Code List
