最近学习新浪微博开放平台，实现了一个应用，通过后台Service监控微博数据，发现数据更新后通知前台程序，并将博客数据列表发送给前台Activity。
其中利用BroadcastReceiver对象分别在Activity和Service注册了一个广播，通过发送不同的广播控制前台和后台的数据交换，并通过Serializable对象传递复杂的自定义对象类型给Activity。
程序片段如下：后台监控weibo Service
[代码] AndriodFocusMe 主UI界面Activity
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public class AndriodFocusMe extends Activity implements Runnable{
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/** Called when the activity is first created. */
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DataReceiver dataReceiver;//BroadcastReceiver对象
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ProgressBar progressbar;
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ListView listview;
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int CMD_STOP_SERVICE = 0;
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int CMD_RESET_SERVICE = 1;
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int CMD_GET_WEIBO_DATA = 2;
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.weibodataview);
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Button beginOuathBtn=(Button) findViewById(R.id.Button_WeiBo);
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Button endBtn = (Button) findViewById(R.id.flashData);
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listview = (ListView)findViewById(R.id.weibodatalist);
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progressbar = (ProgressBar)findViewById(R.id.wbprogressbar);
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progressbar.setVisibility(View.INVISIBLE);
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beginOuathBtn.setOnClickListener(new Button.OnClickListener()
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{
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@Override
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public void onClick( View v )
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{
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Intent myIntent = new Intent(AndriodFocusMe.this, WeiboService.class);
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AndriodFocusMe.this.startService(myIntent);//发送Intent启动Service
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progressbar.setVisibility(View.VISIBLE);
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}
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} );
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endBtn.setOnClickListener(new Button.OnClickListener()
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{
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@Override
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public void onClick( View v )
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{
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Intent intent = new Intent();//创建Intent对象
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intent.setAction("weibo4andriod.focusme.weiboService");
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intent.putExtra("cmd", CMD_GET_WEIBO_DATA);
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sendBroadcast(intent);//发送广播
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}
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} );
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}
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private class DataReceiver extends BroadcastReceiver{//继承自BroadcastReceiver的子类
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ArrayList<HashMap<String, String>> weibodatalist;
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@Override
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public void onReceive(Context context, Intent intent) {//重写onReceive方法
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try {
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Bundle bundle = intent.getExtras();
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//反序列化，在本地重建数据
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Serializable data = bundle.getSerializable("weibodata");
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if (data != null) {
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weibodatalist = (ArrayList<HashMap<String, String>>)data;
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SimpleAdapter mSchedule = newSimpleAdapter(AndriodFocusMe.this,weibodatalist,
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R.layout.weibodata_itemview,
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new String[] {"CreatedAt", "WeiBoText"},
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new int[] {R.id.title,R.id.weibotext});
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listview.setAdapter(mSchedule);
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} else {
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return;
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}
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} catch (Exception e) {
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Log.v("test", e.toString());
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}
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progressbar.setVisibility(View.GONE);
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}
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}
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@Override
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protected void onStart() {//重写onStart方法
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//注册用于接收Service传送的广播
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dataReceiver = new DataReceiver();
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IntentFilter filter = new IntentFilter();//创建IntentFilter对象
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filter.addAction("weiboDataChanged");
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registerReceiver(dataReceiver, filter);//注册Broadcast Receiver
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NotificationManager m_NotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
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m_NotificationManager.cancel(R.id.TextView01);
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super.onStart();
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}
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@Override
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protected void onStop() {//重写onStop方法
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unregisterReceiver(dataReceiver);
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finish();
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super.onStop();
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}
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}
[代码] [Java]代码
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//继承自Service的子类
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public class WeiboService extends Service{
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//用于判断微博是否有更新标志
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private boolean newDateFlag = false;
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//微博对象
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Weibo weibo;
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NotificationManager m_NotificationManager;
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Notification m_Notification;
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PendingIntent m_PendingIntent;
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//继承自BroadcastReceiver对象，用于得到Activity发送过来的命令
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CommandReceiver cmdReceiver;
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boolean flag;
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//Service命令列表
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int CMD_STOP_SERVICE = 0;
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int CMD_RESET_SERVICE = 1;
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int CMD_GET_WEIBO_DATA = 2;
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@Override
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public void onCreate() {//重写onCreate方法
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flag = true;
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//初始化新浪weibo open api
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System.setProperty("weibo4j.oauth.consumerKey", Weibo.CONSUMER_KEY);
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System.setProperty("weibo4j.oauth.consumerSecret", Weibo.CONSUMER_SECRET);
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weibo=OAuthConstant.getInstance().getWeibo();
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//注册时，新浪给你的两个字符串，填写上去
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weibo.setToken("xxxxxx", "xxxxxxxx");
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m_Notification = new Notification();
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super.onCreate();
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}
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@Override
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public IBinder onBind(Intent intent) {//重写onBind方法
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// TODO Auto-generated method stub
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return null;
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}
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//前台Activity调用startService时，该方法自动执行
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@Override
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public int onStartCommand(Intent intent, int flags, int startId) {//重写onStartCommand方法
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cmdReceiver = new CommandReceiver();
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IntentFilter filter = new IntentFilter();//创建IntentFilter对象
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//注册一个广播，用于接收Activity传送过来的命令，控制Service的行为，如：发送数据，停止服务等
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//字符串：weibo4andriod.focusme.weiboService为自定义，没有什么要求，一般用包名+文件名，避免重复
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//如果重复，Android系统在运行期会显示一个接收相同Action的服务程序列表，供用户选择。
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//注册同一个action的程序，能否同时接收广播，待测试.....
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filter.addAction("weibo4andriod.focusme.weiboService");
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//注册Broadcast Receiver
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registerReceiver(cmdReceiver, filter);
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doJob();//调用方法启动线程
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return super.onStartCommand(intent, flags, startId);
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}
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//方法：
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public void doJob(){
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new Thread(){
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public void run(){
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ArrayList<HashMap<String,String>> data;
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while(flag){
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try{//睡眠一段时间
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Thread.sleep(5000);
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}
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catch(Exception e){
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e.printStackTrace();
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}
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data = getWeiboData();
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if(isNewDateFlag()){
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sendNotification("xxxxxxxxx");
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}
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setNewDateFlag(false);
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}
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}
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}.start();
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}
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//接收Activity传送过来的命令
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private class CommandReceiver extends BroadcastReceiver{
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@Override
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public void onReceive(Context context, Intent intent) {
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int cmd = intent.getIntExtra("cmd", -1);//获取Extra信息
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if(cmd == CMD_STOP_SERVICE){//如果发来的消息是停止服务
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flag = false;//停止线程
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stopSelf();//停止服务
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}
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if(cmd == CMD_RESET_SERVICE){//如果发来的消息是刷新服务
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}
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if(cmd == CMD_GET_WEIBO_DATA){//如果发来的消息是发送weibo数据
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sendWeiboData();
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}
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}
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}
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@Override
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public void onDestroy() {//重写onDestroy方法
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this.unregisterReceiver(cmdReceiver);//取消注册的CommandReceiver
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super.onDestroy();
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}
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/**
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* Get Weibo data
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*/
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public ArrayList<HashMap<String,String>> getWeiboData(){
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ArrayList<HashMap<String,String>> weiboDataList
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= new ArrayList<HashMap<String,String>>();
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HashMap<String, String> map
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= new HashMap<String, String>();
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List<Status> friendsTimeline;
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try {
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friendsTimeline = weibo.getUserTimeline();
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for (Status status : friendsTimeline) {
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ofCheckNewWeibo(status.getCreatedAt());
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map = new HashMap<String, String>();
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map.put("CreatedAt", status.getCreatedAt().toString());
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map.put("WeiBoText", status.getText());
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weiboDataList.add(map);
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}
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}
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catch (WeiboException e) {
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e.printStackTrace();
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}
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return weiboDataList;
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}
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private void ofCheckNewWeibo(Date createdAt) {
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// TODO Auto-generated method stub
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Date weibolastdate;
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Editor editor;
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//通过SharedPreFerence读取和记录系统配置信息
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SharedPreferences preferences = getSharedPreferences("weiboDate",Context.MODE_PRIVATE);
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weibolastdate = SParseD(preferences.getString("lastDate","Mon Nov 29 16:08:43 +0800 1900"));
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if(weibolastdate.before(createdAt)){
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editor = preferences.edit();
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editor.putString("lastDate", createdAt.toString());
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editor.commit();
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setNewDateFlag(true);
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}
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}
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/**
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* 发送有微博更新的通知
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* @param sendText
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*/
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public void sendNotification(String sendText){
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Intent intent = new Intent(WeiboService.this,AndriodFocusMe.class);
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m_Notification.icon=R.drawable.icon;
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m_Notification.tickerText=sendText;
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m_Notification.defaults=Notification.DEFAULT_SOUND;
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m_PendingIntent=PendingIntent.getActivity(WeiboService.this, 0,intent, 0);
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m_Notification.setLatestEventInfo(WeiboService.this, "title","text",m_PendingIntent);
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m_NotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
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m_NotificationManager.notify(R.id.TextView01,m_Notification);
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}
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/**
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* String to Date
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* @param date
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* @return
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*/
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//比较数据是否为新的
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public Date SParseD(String date){
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String format = "EEE MMM dd HH:mm:ss Z yyyy";
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SimpleDateFormat dateFormat = new SimpleDateFormat(format, Locale.US);
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Date parseDate = null;
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try {
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parseDate = dateFormat.parse(date);
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} catch (ParseException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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}
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return parseDate;
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}
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public boolean isNewDateFlag() {
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return newDateFlag;
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}
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public void setNewDateFlag(boolean newDateFlag) {
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this.newDateFlag = newDateFlag;
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}
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//发送微博数据列表
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public void sendWeiboData() {
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// TODO Auto-generated method stub
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ArrayList<HashMap<String,String>> Data;
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Data = getWeiboData();
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Intent intent = new Intent();//创建Intent对象
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Bundle bundle = new Bundle();
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//序列化列表，发送后在本地重建数据
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bundle.putSerializable("weibodata",Data);
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intent.setAction("weiboDataChanged");
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intent.putExtras(bundle);
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sendBroadcast(intent);//发送广播
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}
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}
