通常我們?cè)谶M(jìn)行網(wǎng)絡(luò)請(qǐng)求之前魄眉,會(huì)先進(jìn)行網(wǎng)絡(luò)狀態(tài)判斷争占,再?zèng)Q定是否進(jìn)行網(wǎng)絡(luò)請(qǐng)求燃逻,常用方法如下:
/**
* 判斷網(wǎng)絡(luò)是否可用
*
* @return true/false
*/
@SuppressLint("MissingPermission")
public static boolean isNetworkAvailable() {
ConnectivityManager connMgr = (ConnectivityManager) NetworkListener.getInstance().getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
if (connMgr == null) {
return false;
}
NetworkInfo[] infos = connMgr.getAllNetworkInfo();
if (infos != null) {
for (NetworkInfo info : infos) {
if (info.getState() == NetworkInfo.State.CONNECTED) {
return true;
}
}
}
return false;
}
/**
* 獲取當(dāng)前網(wǎng)絡(luò)類(lèi)型
*
* @return NetType
*/
@SuppressLint("MissingPermission")
public static NetType getNetType() {
ConnectivityManager connMgr = (ConnectivityManager) NetworkListener.getInstance().getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
if (connMgr == null) {
return NetType.NONE;
}
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo == null) {
return NetType.NONE;
}
int nType = networkInfo.getType();
if (nType == ConnectivityManager.TYPE_MOBILE) {
if ("cmnet".equals(networkInfo.getExtraInfo().toLowerCase())) {
return NetType.CMNET;
} else {
return NetType.CMWAP;
}
} else if (nType == ConnectivityManager.TYPE_WIFI) {
return NetType.WIFI;
}
return NetType.NONE;
}
但這種做法無(wú)法做到即時(shí)網(wǎng)絡(luò)監(jiān)聽(tīng),例如在播放視頻或下載文件過(guò)程中臂痕,網(wǎng)絡(luò)狀態(tài)發(fā)生變化伯襟,我們無(wú)法做到即時(shí)處理,解決方式有2種:
1握童、使用廣播方式
2姆怪、使用ConnectivityManager.NetworkCallback方式
本次我們先使用廣播監(jiān)聽(tīng)的方式進(jìn)行網(wǎng)絡(luò)變化監(jiān)聽(tīng)。
我們知道澡绩,網(wǎng)絡(luò)狀態(tài)發(fā)生變化的時(shí)候稽揭,系統(tǒng)會(huì)發(fā)出android.net.CONNECTIVITY_CHANGE廣播,所以我們可以用監(jiān)聽(tīng)此廣播的方式來(lái)判斷網(wǎng)絡(luò)連接:
1肥卡、權(quán)限申請(qǐng)
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
2溪掀、創(chuàng)建常量
//網(wǎng)絡(luò)連接改變廣播
public static final String ANDROID_NET_CHANGE_ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
3、定義枚舉類(lèi)步鉴,表示網(wǎng)絡(luò)狀態(tài):
public enum NetType {
//任意網(wǎng)絡(luò)
AUTO,
//WIFI
WIFI,
CMNET,
//手機(jī)上網(wǎng)
CMWAP,
//無(wú)網(wǎng)絡(luò)
NONE
}
4揪胃、定義網(wǎng)絡(luò)監(jiān)聽(tīng)接口
public interface NetChangeListener {
/**
* 已連接
* @param netType NetType
*/
void onConnect(NetType netType);
/**
* 連接斷開(kāi)
*/
void onDisConnect();
}
5、創(chuàng)建廣播接收者
public class NetworkStateReceiver extends BroadcastReceiver {
private static final String TAG = "NetworkStateReceiver";
private NetType netType;//網(wǎng)絡(luò)類(lèi)型
private NetChangeListener listener;
public NetworkStateReceiver() {
//初始化網(wǎng)絡(luò)連接狀態(tài)
this.netType = NetType.NONE;
}
public void setListener(NetChangeListener listener) {
this.listener = listener;
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent == null || intent.getAction() == null) {
Log.e(TAG, "onReceive: 異常");
return;
}
if (intent.getAction().equals(Constants.ANDROID_NET_CHANGE_ACTION)) {
Log.d(TAG, "onReceive: 網(wǎng)絡(luò)發(fā)生變化");
//獲取當(dāng)前聯(lián)網(wǎng)的網(wǎng)絡(luò)類(lèi)型
netType = NetworkUtils.getNetType();
if (NetworkUtils.isNetworkAvailable()) {
Log.d(TAG, "onReceive: 網(wǎng)絡(luò)連接成功");
if (listener != null) {
listener.onConnect(netType);
}
} else {
Log.e(TAG, "onReceive: 網(wǎng)絡(luò)連接失敗");
if (listener != null) {
listener.onDisConnect();
}
}
}
}
}
6氛琢、定義NetworkListener類(lèi)(單例)用于初始化監(jiān)聽(tīng)
public class NetworkListener {
private Context context;
private NetworkStateReceiver receiver;
/**
* 私有化構(gòu)造方法
*/
private NetworkListener() {
receiver = new NetworkStateReceiver();
}
private static final SingletonTemplate<NetworkListener> INSTANCE = new SingletonTemplate<NetworkListener>() {
@Override
protected NetworkListener create() {
return new NetworkListener();
}
};
public static NetworkListener getInstance() {
return INSTANCE.get();
}
public Context getContext() {
return context;
}
public void setListener(NetChangeListener listener) {
receiver.setListener(listener);
}
/**
* 初始化
*
* @param context context
*/
@SuppressLint("MissingPermission")
public void init(Context context) {
this.context = context;
IntentFilter filter = new IntentFilter();
filter.addAction(Constants.ANDROID_NET_CHANGE_ACTION);
context.registerReceiver(receiver, filter);
}
}
7喊递、使用:
Application中初始化:
NetworkListener.getInstance().init(this);
在需要監(jiān)聽(tīng)的Activity中實(shí)現(xiàn)NetChangeListener接口,并在onCreate()中初始化NetworkListener艺沼,如下:
public class MainActivity extends AppCompatActivity implements NetChangeListener {
private static final String TAG = "MainActivity";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
NetworkListener.getInstance().setListener(this);
}
@Override
public void onConnect(NetType netType) {
Log.d(TAG, "onConnect: 網(wǎng)絡(luò)連接成功:狀態(tài)_" + netType.name());
}
@Override
public void onDisConnect() {
Log.e(TAG, "onDisConnect: 網(wǎng)絡(luò)連接斷開(kāi)");
}
}
通過(guò)以上代碼册舞,我們可以實(shí)現(xiàn)在APP運(yùn)行過(guò)程中實(shí)時(shí)監(jiān)聽(tīng)網(wǎng)絡(luò)連接狀態(tài),此方式使用廣播監(jiān)聽(tīng)結(jié)合接口回調(diào)實(shí)現(xiàn)障般。
但此種方式也有個(gè)缺點(diǎn):我們每次需要進(jìn)行網(wǎng)絡(luò)監(jiān)聽(tīng)都需要實(shí)現(xiàn)NetChangeListener這個(gè)接口调鲸,并且如果我們只需要對(duì)某一個(gè)網(wǎng)絡(luò)連接如WIFI或者GPRS進(jìn)行處理的話盛杰,也需要寫(xiě)很多判斷代碼,會(huì)顯得比較繁瑣藐石,那么有沒(méi)有一種更好的實(shí)現(xiàn)方式呢即供,當(dāng)然有!我們可以借助注解的方式實(shí)現(xiàn)監(jiān)聽(tīng)于微,下面我們來(lái)看一下具體操作:
1逗嫡、自定義注解
@Target(ElementType.METHOD)//作用在方法之上
@Retention(RetentionPolicy.RUNTIME)//jvm運(yùn)行時(shí),通過(guò)反射獲取該注解的值
public @interface Network {
NetType netType();
}
2株依、每個(gè)類(lèi)中可能有多個(gè)注解方法驱证,那么我們需要將APP里所有添加注解的類(lèi)放入一個(gè)全局的集合中
private Map<Object,List<MethodManager>> networkMap;
其中Key是類(lèi)(Activity/Fragment),Value是類(lèi)中使用了注解的方法Method恋腕。MethodManager保存了符合要求的網(wǎng)絡(luò)監(jiān)聽(tīng)注解方法抹锄,可以根據(jù)方法的參數(shù)類(lèi)型、網(wǎng)絡(luò)類(lèi)型來(lái)確定:
/**
* 保存符合要求的網(wǎng)絡(luò)監(jiān)聽(tīng)注解方法
* Created by ywd on 2019/6/12.
*/
public class MethodManager {
//方法的類(lèi)型(NetType)
private Class<?> type;
//網(wǎng)絡(luò)類(lèi)型(netType = NetType.WIFI)
private NetType netType;
//需要執(zhí)行的方法(自動(dòng)執(zhí)行)
private Method method;
public MethodManager(Class<?> type, NetType netType, Method method) {
this.type = type;
this.netType = netType;
this.method = method;
}
public Class<?> getType() {
return type;
}
public void setType(Class<?> type) {
this.type = type;
}
public NetType getNetType() {
return netType;
}
public void setNetType(NetType netType) {
this.netType = netType;
}
public Method getMethod() {
return method;
}
public void setMethod(Method method) {
this.method = method;
}
}
3荠藤、定義了集合之后伙单,我們需要為Activity/Fragment添加注冊(cè)和移除方法,該方法只在NetworkListener類(lèi)中提供對(duì)外方法哈肖,核心實(shí)現(xiàn)需要在Receiver中:
/**
* 網(wǎng)絡(luò)監(jiān)聽(tīng)
* Created by ywd on 2019/6/5.
*/
public class NetworkListenerWithAnno {
private Context context;
private NetworkStateReceiverWithAnno receiver;
/**
* 私有化構(gòu)造方法
*/
private NetworkListenerWithAnno() {
receiver = new NetworkStateReceiverWithAnno();
}
private static final SingletonTemplate<NetworkListenerWithAnno> INSTANCE = new SingletonTemplate<NetworkListenerWithAnno>() {
@Override
protected NetworkListenerWithAnno create() {
return new NetworkListenerWithAnno();
}
};
public static NetworkListenerWithAnno getInstance() {
return INSTANCE.get();
}
public Context getContext() {
return context;
}
/**
* 初始化
*
* @param context context
*/
@SuppressLint("MissingPermission")
public void init(Context context) {
this.context = context;
IntentFilter filter = new IntentFilter();
filter.addAction(Constants.ANDROID_NET_CHANGE_ACTION);
context.registerReceiver(receiver, filter);
}
/**
* 注冊(cè)
*
* @param observer 觀察者(Activity/Fragment)
*/
public void registerObserver(Object observer) {
receiver.registerObserver(observer);
}
/**
* 解除注冊(cè)
*
* @param observer 觀察者(Activity/Fragment)
*/
public void unRegisterObserver(Object observer) {
receiver.unRegisterObserver(observer);
}
}
Receiver中的實(shí)現(xiàn):
/**
* 注冊(cè)
* 獲取Activity/Fragment中的注解方法并添加到networkList中
*
* @param observer 觀察者(Activity/Fragment)
*/
public void registerObserver(Object observer) {
List<MethodManager> methodList = networkMap.get(observer);
if (methodList == null) {
methodList = findAnnotationMethod(observer);
networkMap.put(observer, methodList);
}
}
/**
* 解除注冊(cè)
*
* @param observer 觀察者(Activity/Fragment)
*/
public void unRegisterObserver(Object observer) {
if (!networkMap.isEmpty()) {
networkMap.remove(observer);
}
Log.d(TAG, "unRegisterObserver:" + observer.getClass().getName() + "注銷(xiāo)成功");
}
findAnnotationMethod(observer)方法為獲取Activity/Fragment中的注解方法吻育,可以在此類(lèi)中進(jìn)行過(guò)濾,具體實(shí)現(xiàn)如下:
/**
* 獲取Activity/Fragment中的注解方法
* @param observer 觀察者(Activity/Fragment)
* @return
*/
private List<MethodManager> findAnnotationMethod(Object observer) {
List<MethodManager> methodList = new ArrayList<>();
Class<?> clazz = observer.getClass();
//獲取Activity中的所有公有方法淤井,包括其父類(lèi)及其實(shí)現(xiàn)的接口的方法布疼,因方法數(shù)過(guò)多,此處使用getDeclaredMethods()
//Method[] methods = clazz.getMethods();
//獲取Activity中的所有方法庄吼,包括公共缎除、保護(hù)、默認(rèn)(包)訪問(wèn)和私有方法,當(dāng)然也包括它所實(shí)現(xiàn)接口的方法总寻,但不包括繼承的方法
Method[] methods = clazz.getDeclaredMethods();
for (Method method : methods) {
//獲取方法的注解
Network network = method.getAnnotation(Network.class);
if (network == null) {
continue;
}
//方法參數(shù)校驗(yàn)
Class<?>[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length != 1) {
throw new RuntimeException(method.getName() + "方法有且只有一個(gè)參數(shù)");
}
//參數(shù)類(lèi)型校驗(yàn)
String name = parameterTypes[0].getName();
if (name.equals(NetType.class.getName())) {
MethodManager methodManager = new MethodManager(parameterTypes[0], network.netType(), method);
methodList.add(methodManager);
}
}
return methodList;
}
獲取到Activity/Fragment中的所有注解方法之后器罐,就可以在網(wǎng)絡(luò)發(fā)生變化時(shí)進(jìn)行事件分發(fā)了,接下來(lái)我們?cè)趏nReceive中進(jìn)行處理:
if (intent == null || intent.getAction() == null) {
Log.e(TAG, "onReceive: 異常");
return;
}
if (intent.getAction().equals(Constants.ANDROID_NET_CHANGE_ACTION)) {
Log.d(TAG, "onReceive: 網(wǎng)絡(luò)發(fā)生變化");
netType = NetworkUtils.getNetType();
if (NetworkUtils.isNetworkAvailable()) {
Log.d(TAG, "onReceive: 網(wǎng)絡(luò)連接成功");
} else {
Log.e(TAG, "onReceive: 網(wǎng)絡(luò)連接失敗");
}
post(netType);
}
post方法實(shí)現(xiàn):
/**
* 分發(fā)
*
* @param netType NetType
*/
private void post(NetType netType) {
//Activity集合
Set<Object> set = networkMap.keySet();
for (Object observer : set) {
//所有注解的方法
List<MethodManager> methodList = networkMap.get(observer);
if (methodList != null) {
for (MethodManager methodManager : methodList) {
//兩者參數(shù)比較
if (methodManager.getType().isAssignableFrom(netType.getClass())) {
switch (methodManager.getNetType()) {
case AUTO:
invoke(methodManager, observer, netType);
break;
case WIFI:
if (netType == NetType.WIFI || netType == NetType.NONE) {
invoke(methodManager, observer, netType);
}
break;
case CMWAP:
if (netType == NetType.CMWAP || netType == NetType.NONE) {
invoke(methodManager, observer, netType);
}
break;
case CMNET:
if (netType == NetType.CMNET || netType == NetType.NONE) {
invoke(methodManager, observer, netType);
}
break;
}
}
}
}
}
}
invoke方法:
/**
* 在Activity中執(zhí)行方法渐行,參數(shù)為NetType
*
* @param methodManager
* @param observer
* @param netType
*/
private void invoke(MethodManager methodManager, Object observer, NetType netType) {
try {
methodManager.getMethod().invoke(observer, netType);
} catch (IllegalAccessException | InvocationTargetException e) {
e.printStackTrace();
}
}
使用:
@Network(netType = NetType.WIFI)
public void onNetChanged(NetType netType) {
Log.d(TAG, "onNetChanged: 網(wǎng)絡(luò)發(fā)生改變" + netType.name());
}
可以看到轰坊,通過(guò)反射+注解形式,在使用上更加簡(jiǎn)潔祟印,同時(shí)相比接口回調(diào)形式更加解耦肴沫。
注意:Android7.0為了提高用戶(hù)體驗(yàn)和提升設(shè)備性能移除了這個(gè)隱式廣播,所以利用靜態(tài)注冊(cè)的方式是不能接收到該廣播的蕴忆,如果需要使用廣播方式監(jiān)聽(tīng)網(wǎng)絡(luò)變化可以使用動(dòng)態(tài)注冊(cè)的方式進(jìn)行接收颤芬。
代碼詳見(jiàn)Demo
PS:本文為某平臺(tái)公開(kāi)課筆記,在此記錄下,文中實(shí)現(xiàn)還可以再次進(jìn)行優(yōu)化站蝠。
另附使用ConnectivityManager.NetworkCallback方式實(shí)現(xiàn)網(wǎng)絡(luò)監(jiān)聽(tīng):
詳見(jiàn)
Android即時(shí)網(wǎng)絡(luò)監(jiān)聽(tīng)(二)-ConnectivityManager.NetworkCallback