这次手机平台应用开发课程设计我们选择了新闻类App作为小组开发的题目。于是再动手写代码前,我们各组员分头在网络上搜索了各式各样的新闻类App来学习,分析那些作者们的设计思路。
当我看到这份作品时真的是十分震惊,首先是作者博客中的缩略图让人眼熟,于是将Github上的代码拉到本地尝试运行,前几次可能是配置上出现了冲突,导致没有成功连接网络,所以没有新闻刷新。当重新设置好后,鼠标在虚拟安卓机下拉的时候跳出今日新闻,效果很是让人兴奋。之后我又在应用商店里下载正版的今日头条App,界面可以说是大同小异,而新闻内容则真是如出一辙。当时我就下定决心要研究研究这位作者的代码,看看他是如何利用手头仅有的资源开发出近乎一致的商用应用的。
作品出自:http://blog.youkuaiyun.com/Chay_Chan/article/details/75319452
谈谈作者遇到的问题吧,这也是我重点关注的部分。
问题一:根据网络上流出的抓包知道的接口来获取新闻列表,后台接口却获取不到数据,后来了解到fidder可以解https的数据包,今日头条的新闻数据获取问题就迎刃而解。
问题二:新闻数据的规律,新闻列表的item布局有好多种,在没有接口文档的前提下,需要根据返回的json数据进行分析,找出规律,知道根据哪个字段来判断属于哪个布局。
问题三:视频解析,之前是读取新闻详情页的html页面,通过正则匹配出对应视频的地址。如今找到了一个解析今日头条视频地址的网站,通过传入详情页的网址就能够获取到对应视频的地址,所以开始抓包获取那个接口,视频解析的问题迎刃而解。
实现的功能:
1.获取各种频道的新闻列表,包括视频和非视频新闻;
2.查看新闻详情,包括视频和非视频新闻的详情;
3.查看新闻评论列表;
4.新闻数据本地存储,已经获取到的新闻数据保存在本地数据库中,上拉加载更多时可查看历史新闻;
5.底部页签点击下拉刷新;
6.视频列表播放中的视频不可见时停止播放。
7.查看和保存图片。
技术要点:
1.新闻数据的抓取和分析,使用fidder抓取,具体使用可参考下面的网址:
http://www.tuicool.com/articles/BJjQZf
2.新闻列表多种Item布局的展示,使用的是BaseRecyclerViewAdapterHelper,ReclerView万能适配器,多布局使用可参考下面的网址:
https://github.com/CymChad/BaseRecyclerViewAdapterHelper/issues/968
截取管理App视频播放部分的代码如下:
(这部分代码实现了解析视频的播放,以及对播放视频资源的管理)
package fm.jiecao.jcvideoplayer_lib;
import android.graphics.Point;
import android.graphics.SurfaceTexture;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
import android.view.Surface;
import android.view.TextureView;
import java.lang.reflect.Method;
import java.util.Map;
/**
* <p>统一管理MediaPlayer的地方,只有一个mediaPlayer实例,那么不会有多个视频同时播放,也节省资源。</p>
* <p>Unified management MediaPlayer place, there is only one MediaPlayer instance, then there will be no more video broadcast at the same time, also save resources.</p>
* Created by Nathen
* On 2015/11/30 15:39
*/
public class JCMediaManager implements TextureView.SurfaceTextureListener, MediaPlayer.OnPreparedListener, MediaPlayer.OnCompletionListener, MediaPlayer.OnBufferingUpdateListener, MediaPlayer.OnSeekCompleteListener, MediaPlayer.OnErrorListener, MediaPlayer.OnInfoListener, MediaPlayer.OnVideoSizeChangedListener {
public static String TAG = "JieCaoVideoPlayer";
private static JCMediaManager JCMediaManager;
public static JCResizeTextureView textureView;
public static SurfaceTexture savedSurfaceTexture;
public MediaPlayer mediaPlayer = new MediaPlayer();
public static String CURRENT_PLAYING_URL;
public static boolean CURRENT_PLING_LOOP;
public static Map<String, String> MAP_HEADER_DATA;
public int currentVideoWidth = 0;
public int currentVideoHeight = 0;
public static final int HANDLER_PREPARE = 0;
public static final int HANDLER_RELEASE = 2;
HandlerThread mMediaHandlerThread;
MediaHandler mMediaHandler;
Handler mainThreadHandler;
public static JCMediaManager instance() {
if (JCMediaManager == null) {
JCMediaManager = new JCMediaManager();
}
return JCMediaManager;
}
public JCMediaManager() {
mMediaHandlerThread = new HandlerThread(TAG);
mMediaHandlerThread.start();
mMediaHandler = new MediaHandler((mMediaHandlerThread.getLooper()));
mainThreadHandler = new Handler();
}
public Point getVideoSize() {
if (currentVideoWidth != 0 && currentVideoHeight != 0) {
return new Point(currentVideoWidth, currentVideoHeight);
} else {
return null;
}
}
public class MediaHandler extends Handler {
public MediaHandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case HANDLER_PREPARE:
try {
currentVideoWidth = 0;
currentVideoHeight = 0;
mediaPlayer.release();
mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
Class<MediaPlayer> clazz = MediaPlayer.class;
Method method = clazz.getDeclaredMethod("setDataSource", String.class, Map.class);
method.invoke(mediaPlayer, CURRENT_PLAYING_URL, MAP_HEADER_DATA);
mediaPlayer.setLooping(CURRENT_PLING_LOOP);
mediaPlayer.setOnPreparedListener(JCMediaManager.this);
mediaPlayer.setOnCompletionListener(JCMediaManager.this);
mediaPlayer.setOnBufferingUpdateListener(JCMediaManager.this);
mediaPlayer.setScreenOnWhilePlaying(true);
mediaPlayer.setOnSeekCompleteListener(JCMediaManager.this);
mediaPlayer.setOnErrorListener(JCMediaManager.this);
mediaPlayer.setOnInfoListener(JCMediaManager.this);
mediaPlayer.setOnVideoSizeChangedListener(JCMediaManager.this);
mediaPlayer.prepareAsync();
mediaPlayer.setSurface(new Surface(savedSurfaceTexture));
} catch (Exception e) {
e.printStackTrace();
}
break;
case HANDLER_RELEASE:
mediaPlayer.release();
break;
}
}
}
public void prepare() {
releaseMediaPlayer();
Message msg = new Message();
msg.what = HANDLER_PREPARE;
mMediaHandler.sendMessage(msg);
}
public void releaseMediaPlayer() {
Message msg = new Message();
msg.what = HANDLER_RELEASE;
mMediaHandler.sendMessage(msg);
}
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {
Log.i(TAG, "onSurfaceTextureAvailable [" + this.hashCode() + "] ");
if (savedSurfaceTexture == null) {
savedSurfaceTexture = surfaceTexture;
prepare();
} else {
textureView.setSurfaceTexture(savedSurfaceTexture);
}
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {
// 如果SurfaceTexture还没有更新Image,则记录SizeChanged事件,否则忽略
Log.i(TAG, "onSurfaceTextureSizeChanged [" + this.hashCode() + "] ");
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
return savedSurfaceTexture == null;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
}
@Override
public void onPrepared(MediaPlayer mp) {
mediaPlayer.start();
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onPrepared();
}
}
});
}
@Override
public void onCompletion(MediaPlayer mp) {
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onAutoCompletion();
}
}
});
}
@Override
public void onBufferingUpdate(MediaPlayer mp, final int percent) {
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().setBufferProgress(percent);
}
}
});
}
@Override
public void onSeekComplete(MediaPlayer mp) {
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onSeekComplete();
}
}
});
}
@Override
public boolean onError(MediaPlayer mp, final int what, final int extra) {
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onError(what, extra);
}
}
});
return true;
}
@Override
public boolean onInfo(MediaPlayer mp, final int what, final int extra) {
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onInfo(what, extra);
}
}
});
return false;
}
@Override
public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
currentVideoWidth = width;
currentVideoHeight = height;
mainThreadHandler.post(new Runnable() {
@Override
public void run() {
if (JCVideoPlayerManager.getCurrentJcvd() != null) {
JCVideoPlayerManager.getCurrentJcvd().onVideoSizeChanged();
}
}
});
}
}