在Android開發(fā)過程中，很多時(shí)候都會(huì)用到當(dāng)前網(wǎng)絡(luò)的狀態(tài)判斷以及網(wǎng)絡(luò)狀況發(fā)生變化的時(shí)候做出相應(yīng)的反應(yīng)，要想監(jiān)聽網(wǎng)絡(luò)狀態(tài)，用觀察者模式再合適不過了，廢話不多說，直接上代碼。
觀察者模式屬于面向?qū)ο蟮?3中設(shè)計(jì)模式之一，不了解的同學(xué)請(qǐng)自行Google
既然用觀察者模式，自然離不開觀察者模式里最重要的兩個(gè)類Subject和Ovserver了
Subjcet接口：
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/** * Description: observer subject * author: Wang * date: 11/28/16 11:19 AM * * Copyright©2016 by wang. All rights reserved. */public interface NetConnectionSubject { /** * 注冊(cè)觀察者 * * @param observer */ public void addNetObserver(NetConnectionObserver observer); /** * 移除觀察者 * * @param observer */ public void removeNetObserver(NetConnectionObserver observer); /** * 狀態(tài)更新通知 * * @param type */ public void notifyNetObserver(int type);} |
Observer接口：
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/** * Description: observer * author: Wang * date: 11/28/16 11:20 AM * * Copyright©2016 by wang. All rights reserved. */public interface NetConnectionObserver { /** * 通知觀察者更改狀態(tài) * * @param type */ public void updateNetStatus(int type);} |
在Android里，最適合實(shí)現(xiàn)Subject類的，莫過于Application了，因?yàn)樗治ㄒ欢疑芷诰褪沁@個(gè)App的生命周期：
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/** * Description: App's application should extend this class * author: Wang * date: 11/28/16 10:34 AM * * Copyright©2016 by wang. All rights reserved. */public abstract class BaseApplication extends Application implements NetConnectionSubject { protected static BaseApplication instance; private int currentNetType = -1; private List<NetConnectionObserver> observers = new ArrayList<>(); public static BaseApplication getInstance() { return instance; } /** * current net connection type * * @return */ public int getCurrentNetType() { return currentNetType; } /** * current net connection status * * @return */ public boolean isNetConnection() { return currentNetType == NetWorkUtil.NET_NO_CONNECTION ? false : true; } @Override public void onCreate() { super.onCreate(); instance = this; currentNetType = NetWorkUtil.getConnectionType(this); } @Override public void addNetObserver(NetConnectionObserver observer) { if (!observers.contains(observer)) { observers.add(observer); } } @Override public void removeNetObserver(NetConnectionObserver observer) { if (observers != null && observers.contains(observer)) { observers.remove(observer); } } @Override public void notifyNetObserver(int type) { /** * 避免多次發(fā)送相同的網(wǎng)絡(luò)狀態(tài) */ if (currentNetType == type) { return; } else { currentNetType = type; if (observers != null && observers.size() > 0) { for (NetConnectionObserver observer : observers) { observer.updateNetStatus(type); } } } }} |
具體誰要實(shí)現(xiàn)Observer接口，就要看具體場(chǎng)景了，這里以Activity為栗子吧：
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/** * Description: TODO * author: WangKunHui * date: 16/12/30 下午3:08 * <p> * Copyright©2016 by wang. All rights reserved. */public class TestActivity extends Activity implements NetConnectionObserver { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); /**省略一些方法**/ BaseApplication.getInstance().addNetObserver(this); } @Override public void updateNetStatus(int type) { //當(dāng)監(jiān)聽網(wǎng)絡(luò)狀態(tài)發(fā)生變化 這里會(huì)及時(shí)的收到回饋 } @Override protected void onDestroy() { super.onDestroy(); BaseApplication.getInstance().removeNetObserver(this); }} |
這里有個(gè)地方一定要注意：當(dāng)Activity銷毀的時(shí)候，一定要把這個(gè)觀察者從觀察者隊(duì)列里移除掉！否者會(huì)發(fā)生內(nèi)存泄漏
到這里，觀察者模式已經(jīng)寫完了，謝謝收看。
讀者：你是不是忘了點(diǎn)什么，說好的網(wǎng)絡(luò)監(jiān)聽呢？
我：Easy easy~ 剛剛只不過是中場(chǎng)休息
如果只有上面那么多的話，是不能監(jiān)聽網(wǎng)絡(luò)狀態(tài)的，想要監(jiān)聽網(wǎng)絡(luò)狀態(tài)的變化，還得靠我們的廣播接收者啊，有請(qǐng)：
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/** * Description: 網(wǎng)絡(luò)連接狀態(tài)的監(jiān)聽 * author: Wang * date: 16/8/3 下午10:54 * * Copyright©2016 by wang. All rights reserved. */public class NetConnectionReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) { int connectionType = NetWorkUtil.getConnectionType(context); /** * 更改網(wǎng)絡(luò)狀態(tài) */ if (BaseApplication.getInstance() != null) { BaseApplication.getInstance().notifyNetObserver(connectionType); } } }} |
NetWorkUtil:
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/** * @author Wang * @version 1.0.0 * @description 網(wǎng)絡(luò)操作工具類 * @create 2014-2-18 上午09:22:30 * @company */public class NetWorkUtil {/** * 無網(wǎng)絡(luò)鏈接 */ public static final int NET_NO_CONNECTION = 0; /** * wifi */ public static final int NET_TYPE_WIFI = 1; public static final int NET_TYPE_2G = 2; public static final int NET_TYPE_3G = 3; public static final int NET_TYPE_4G = 4; /** * 未知的網(wǎng)絡(luò)類型 */ public static final int NET_TYPE_UNKNOWN = 5; /** * 獲取網(wǎng)絡(luò)類型 * * @param context * @return */ public static int getConnectionType(Context context) { int netType = NET_NO_CONNECTION; NetworkInfo networkInfo = ((ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo(); if (networkInfo == null) { netType = NET_NO_CONNECTION; } else { if (networkInfo.getType() == ConnectivityManager.TYPE_WIFI) { netType = NET_TYPE_WIFI; } else { int networkType = networkInfo.getSubtype(); switch (networkType) { case TelephonyManager.NETWORK_TYPE_GPRS: case TelephonyManager.NETWORK_TYPE_EDGE: case TelephonyManager.NETWORK_TYPE_CDMA: case TelephonyManager.NETWORK_TYPE_1xRTT: case TelephonyManager.NETWORK_TYPE_IDEN: //api<8 : replace by 11 netType = NET_TYPE_2G; break; case TelephonyManager.NETWORK_TYPE_UMTS: case TelephonyManager.NETWORK_TYPE_EVDO_0: case TelephonyManager.NETWORK_TYPE_EVDO_A: case TelephonyManager.NETWORK_TYPE_HSDPA: case TelephonyManager.NETWORK_TYPE_HSUPA: case TelephonyManager.NETWORK_TYPE_HSPA: case TelephonyManager.NETWORK_TYPE_EVDO_B: //api<9:replace by 14 case TelephonyManager.NETWORK_TYPE_EHRPD: //api<11:replace by 12 case TelephonyManager.NETWORK_TYPE_HSPAP: //api<13:replace by 15 netType = NET_TYPE_3G; break; case TelephonyManager.NETWORK_TYPE_LTE: //api<11:replace by 13 netType = NET_TYPE_4G; break; default: String subType = networkInfo.getSubtypeName(); if (subType.equalsIgnoreCase("TD-SCDMA") || subType.equalsIgnoreCase("WCDMA") || subType.equalsIgnoreCase("CDMA2000")) { netType = NET_TYPE_3G; } else { netType = NET_TYPE_UNKNOWN; } break; } } } return netType; }} |
好了，到這里，標(biāo)題上所有的內(nèi)容已經(jīng)寫完了，最后，別忘了權(quán)限和注冊(cè)廣播接收者。
以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持服務(wù)器之家。
原文鏈接：https://blog.csdn.net/u012370834/article/details/53943636
