androidRSS例子

/* * $Id: RSSReaderProvider.java 114 2008-02-14 05:09:23Z jasta00 $ * * 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. */ copyDefaultIc