我遇到问题，当我通过手机上的任务管理器关闭我的应用程序时，我的服务再次注册。这是我的代码。
Notification_Service
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import twitter4j.DirectMessage;
import twitter4j.MediaEntity;
import twitter4j.StallWarning;
import twitter4j.Status;
import twitter4j.StatusDeletionNotice;
import twitter4j.TwitterStream;
import twitter4j.TwitterStreamFactory;
import twitter4j.User;
import twitter4j.UserList;
import twitter4j.UserStreamListener;
import twitter4j.auth.AccessToken;
import twitter4j.conf.ConfigurationBuilder;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import com.parse.ParseTwitterUtils;
public class Notification_Service extends Service{
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
TwitterStream twitterStream = new TwitterStreamFactory(new ConfigurationBuilder().setJSONStoreEnabled(true).build()).getInstance();
twitterStream.setOAuthConsumer(ParseTwitterUtils.getTwitter().getConsumerKey(), ParseTwitterUtils.getTwitter().getConsumerSecret());
AccessToken token = new AccessToken(ParseTwitterUtils.getTwitter().getAuthToken(), ParseTwitterUtils.getTwitter().getAuthTokenSecret());
twitterStream.setOAuthAccessToken(token);
twitterStream.addListener(listener);
twitterStream.user();
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
}
UserStreamListener listener = new UserStreamListener() {
@Override
public void onDeletionNotice(StatusDeletionNotice arg0) {
// TODO Auto-generated method stub
}
@Override
public void onScrubGeo(long arg0, long arg1) {
// TODO Auto-generated method stub
}
@Override
public void onStallWarning(StallWarning arg0) {
// TODO Auto-generated method stub
}
@Override
public void onStatus(final Status status) {
// TODO Auto-generated method stub
if(status.getText().contains("@" + ParseTwitterUtils.getTwitter().getScreenName())){
Notify(status.getUser().getScreenName(), status.getUser().getScreenName(), status.getText());
}
Intent intent = new Intent("com.receiveTweet.GrabTweets");
intent.putExtra("tweet_id", status.getId());
/*if(status.isFavorited()){
intent.putExtra("tweetIsFavorited", true);
}else{
intent.putExtra("tweetIsFavorited", false);
}
*/
if(status.isRetweet()){
intent.putExtra("tweet", status.getRetweetedStatus().getText());
}else{
intent.putExtra("tweet", status.getText());
}
intent.putExtra("tweet_name", status.getUser().getName());
intent.putExtra("tweet_screenname", status.getUser().getScreenName());
intent.putExtra("tweet_profilepicture", status.getUser().getProfileImageURL());
MediaEntity []mediaEntities = status.getMediaEntities();
if (mediaEntities != null && status.getMediaEntities().length>0) {
Log.d("MediaEntities","getMediaEntities not null"); //just for testing
if (mediaEntities.length > 0) {
Log.d("MediaEntities","getMediaEntities not null");
intent.putExtra("tweetPicture", mediaEntities[0].getMediaURL().toString());
}
}
LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
}
@Override
public void onTrackLimitationNotice(int arg0) {
// TODO Auto-generated method stub
}
@Override
public void onException(Exception arg0) {
// TODO Auto-generated method stub
}
@Override
public void onBlock(User arg0, User arg1) {
// TODO Auto-generated method stub
}
@Override
public void onDeletionNotice(long arg0, long arg1) {
// TODO Auto-generated method stub
}
@Override
public void onDirectMessage(DirectMessage arg0) {
// TODO Auto-generated method stub
}
@Override
public void onFavorite(User arg0, User arg1, Status arg2) {
// TODO Auto-generated method stub
}
@Override
public void onFollow(User arg0, User arg1) {
// TODO Auto-generated method stub
}
@Override
public void onFriendList(long[] arg0) {
// TODO Auto-generated method stub
}
@Override
public void onUnblock(User arg0, User arg1) {
// TODO Auto-generated method stub
}
@Override
public void onUnfavorite(User arg0, User arg1, Status arg2) {
// TODO Auto-generated method stub
}
@Override
public void onUnfollow(User arg0, User arg1) {
// TODO Auto-generated method stub
}
@Override
public void onUserListCreation(User arg0, UserList arg1) {
// TODO Auto-generated method stub
}
@Override
public void onUserListDeletion(User arg0, UserList arg1) {
// TODO Auto-generated method stub
}
@Override
public void onUserListMemberAddition(User arg0, User arg1, UserList arg2) {
// TODO Auto-generated method stub
}
@Override
public void onUserListMemberDeletion(User arg0, User arg1, UserList arg2) {
// TODO Auto-generated method stub
}
@Override
public void onUserListSubscription(User arg0, User arg1, UserList arg2) {
// TODO Auto-generated method stub
}
@Override
public void onUserListUnsubscription(User arg0, User arg1, UserList arg2) {
// TODO Auto-generated method stub
}
@Override
public void onUserListUpdate(User arg0, UserList arg1) {
// TODO Auto-generated method stub
}
@Override
public void onUserProfileUpdate(User arg0) {
// TODO Auto-generated method stub
}
};
private void Notify(String user,String notificationTitle, String notificationMessage) {
Uri defaultSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
NotificationCompat.Builder builder =
new NotificationCompat.Builder(this)
.setSmallIcon(R.drawable.ic_launcher)
.setTicker("You've Been Mention In A Tweet")
.setSound(defaultSound)
.setContentTitle(notificationTitle)
.setContentText(notificationMessage);
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
builder.setContentIntent(contentIntent);
// Add as notification
NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
manager.notify(908596, builder.build());
}
public void cancelNotification(int notificationId){
if (Context.NOTIFICATION_SERVICE!=null) {
String ns = Context.NOTIFICATION_SERVICE;
NotificationManager nMgr = (NotificationManager) getApplicationContext().getSystemService(ns);
nMgr.cancel(908596);
}
}
public Bitmap getBitmapFromURL(String strURL) {
try {
URL url = new URL(strURL);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}
在我的片段课程的onCreate中，我有这个内容。
getActivity().startService(new Intent(getActivity(), Notification_Service.class));
我在服务中放入一个日志，看看它是我的广播接收器还是服务，但我不断从服务中获取多个日志。如何防止我的服务多次实例化？
答案 0 :(得分：2)
onStartCommand()的默认返回值为START_STICKY，其中指出：
如果此服务的进程在启动时被终止（从onStartCommand（Intent，int，int）返回后），则将其保留在启动状态但不保留此传递的意图。 稍后系统会尝试重新创建服务。
因此，当您关闭应用程序时，Android系统会自动重启您的服务。如果您不希望这种情况发生，您可以返回START_NOT_STICKY（或在特殊情况下START_REDELIVER_INTENT），而不是致电super.onStartCommand()。
请注意，每次调用onStartCommand()（或系统为您重新启动服务）时都会调用startService()。如果您希望在服务的整个生命周期内只运行一次，那么您应该将其放在onCreate()调用中。