Java tutorial
/* * Copyright (C) 2009 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.android.xbrowser; import org.apache.http.HttpEntity; import org.apache.http.HttpHost; import org.apache.http.HttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.params.HttpClientParams; import org.apache.http.conn.params.ConnRouteParams; import android.content.ContentResolver; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Proxy; import android.net.http.AndroidHttpClient; import android.os.AsyncTask; import android.os.Bundle; import android.os.Message; import com.android.external.BrowserContract; import com.android.external.BrowserContract.Images; import android.webkit.WebView; import java.io.ByteArrayOutputStream; import java.io.InputStream; class DownloadTouchIcon extends AsyncTask<String, Void, Void> { private final ContentResolver mContentResolver; private Cursor mCursor; private final String mOriginalUrl; private final String mUrl; private final String mUserAgent; // Sites may serve a different icon to different UAs private Message mMessage; private final Context mContext; /* package */ Tab mTab; /** * Use this ctor to store the touch icon in the bookmarks database for * the originalUrl so we take account of redirects. Used when the user * bookmarks a page from outside the bookmarks activity. */ public DownloadTouchIcon(Tab tab, Context ctx, ContentResolver cr, WebView view) { mTab = tab; mContext = ctx.getApplicationContext(); mContentResolver = cr; // Store these in case they change. mOriginalUrl = view.getOriginalUrl(); mUrl = view.getUrl(); mUserAgent = view.getSettings().getUserAgentString(); } /** * Use this ctor to download the touch icon and update the bookmarks database * entry for the given url. Used when the user creates a bookmark from * within the bookmarks activity and there haven't been any redirects. * TODO: Would be nice to set the user agent here so that there is no * potential for the three different ctors here to return different icons. */ public DownloadTouchIcon(Context ctx, ContentResolver cr, String url) { mTab = null; mContext = ctx.getApplicationContext(); mContentResolver = cr; mOriginalUrl = null; mUrl = url; mUserAgent = null; } /** * Use this ctor to not store the touch icon in a database, rather add it to * the passed Message's data bundle with the key * {@link BrowserContract.Bookmarks#TOUCH_ICON} and then send the message. */ public DownloadTouchIcon(Context context, Message msg, String userAgent) { mMessage = msg; mContext = context.getApplicationContext(); mContentResolver = null; mOriginalUrl = null; mUrl = null; mUserAgent = userAgent; } @Override public Void doInBackground(String... values) { if (mContentResolver != null) { mCursor = Bookmarks.queryCombinedForUrl(mContentResolver, mOriginalUrl, mUrl); } boolean inDatabase = mCursor != null && mCursor.getCount() > 0; String url = values[0]; if (inDatabase || mMessage != null) { AndroidHttpClient client = null; HttpGet request = null; try { client = AndroidHttpClient.newInstance(mUserAgent); HttpHost httpHost = Proxy.getPreferredHttpHost(mContext, url); if (httpHost != null) { ConnRouteParams.setDefaultProxy(client.getParams(), httpHost); } request = new HttpGet(url); // Follow redirects HttpClientParams.setRedirecting(client.getParams(), true); HttpResponse response = client.execute(request); if (response.getStatusLine().getStatusCode() == 200) { HttpEntity entity = response.getEntity(); if (entity != null) { InputStream content = entity.getContent(); if (content != null) { Bitmap icon = BitmapFactory.decodeStream(content, null, null); if (inDatabase) { storeIcon(icon); } else if (mMessage != null) { Bundle b = mMessage.getData(); b.putParcelable(BrowserContract.Bookmarks.TOUCH_ICON, icon); } } } } } catch (Exception ex) { if (request != null) { request.abort(); } } finally { if (client != null) { client.close(); } } } if (mCursor != null) { mCursor.close(); } if (mMessage != null) { mMessage.sendToTarget(); } return null; } @Override protected void onCancelled() { if (mCursor != null) { mCursor.close(); } } private void storeIcon(Bitmap icon) { // Do this first in case the download failed. if (mTab != null) { // Remove the touch icon loader from the BrowserActivity. mTab.mTouchIconLoader = null; } if (icon == null || mCursor == null || isCancelled()) { return; } if (mCursor.moveToFirst()) { final ByteArrayOutputStream os = new ByteArrayOutputStream(); icon.compress(Bitmap.CompressFormat.PNG, 100, os); ContentValues values = new ContentValues(); values.put(Images.TOUCH_ICON, os.toByteArray()); do { values.put(Images.URL, mCursor.getString(0)); mContentResolver.update(Images.CONTENT_URI, values, null, null); } while (mCursor.moveToNext()); } } }