android 实时监听网络状态

纯复制的  我觉得挺好的 主要是怕博主删帖 所以转载一下

原地址:https://www.jianshu.com/p/6fa0f1f1ce48

 

NetStateChangeReceiver

public class NetStateChangeReceiver extends BroadcastReceiver {

    private NetworkType mType = NetworkUtil.getNetworkType(MyApplication.getContext());

    private static class InstanceHolder {
        private static final NetStateChangeReceiver INSTANCE = new NetStateChangeReceiver();
    }

    private List<NetStateChangeObserver> mObservers = new ArrayList<>();

    @Override
    public void onReceive(Context context, Intent intent) {
        if (ConnectivityManager.CONNECTIVITY_ACTION.equals(intent.getAction())) {
            NetworkType networkType = NetworkUtil.getNetworkType(context);
            notifyObservers(networkType);
        }
    }

    public static void registerReceiver(Context context) {
        IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        context.registerReceiver(InstanceHolder.INSTANCE, intentFilter);
    }

    public static void unRegisterReceiver(Context context) {
        context.unregisterReceiver(InstanceHolder.INSTANCE);
    }

    public static void registerObserver(NetStateChangeObserver observer) {
        if (observer == null) {
            return;
        }
        if (!InstanceHolder.INSTANCE.mObservers.contains(observer)) {
            InstanceHolder.INSTANCE.mObservers.add(observer);
        }
    }

    public static void unRegisterObserver(NetStateChangeObserver observer) {
        if (observer == null) {
            return;
        }
        if (InstanceHolder.INSTANCE.mObservers == null) {
            return;
        }
        InstanceHolder.INSTANCE.mObservers.remove(observer);
    }

    private void notifyObservers(NetworkType networkType) {
        if (mType == networkType) {
            return;
        }
        mType = networkType;
        if (networkType == NetworkType.NETWORK_NO) {
            for (NetStateChangeObserver observer : mObservers) {
                observer.onNetDisconnected();
            }
        } else {
            for (NetStateChangeObserver observer : mObservers) {
                observer.onNetConnected(networkType);
            }
        }
    }
}

NetworkUtil

 

public class NetworkUtil {
    private NetworkUtil() {
        throw new UnsupportedOperationException("u can't instantiate me...");
    }

    @RequiresPermission("android.permission.ACCESS_NETWORK_STATE")
    private static NetworkInfo getActiveNetworkInfo(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        return cm.getActiveNetworkInfo();
    }

    /**
     * 获取当前网络类型
     * 需添加权限 {@code <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>}
     */
    @RequiresPermission("android.permission.ACCESS_NETWORK_STATE")
    public static NetworkType getNetworkType(Context context) {
        NetworkType netType = NetworkType.NETWORK_NO;
        NetworkInfo info = getActiveNetworkInfo(context);
        if (info != null && info.isAvailable()) {

            if (info.getType() == ConnectivityManager.TYPE_WIFI) {
                netType = NetworkType.NETWORK_WIFI;
            } else if (info.getType() == ConnectivityManager.TYPE_MOBILE) {
                switch (info.getSubtype()) {

                    case TelephonyManager.NETWORK_TYPE_TD_SCDMA:
                    case TelephonyManager.NETWORK_TYPE_EVDO_A:
                    case TelephonyManager.NETWORK_TYPE_UMTS:
                    case TelephonyManager.NETWORK_TYPE_EVDO_0:
                    case TelephonyManager.NETWORK_TYPE_HSDPA:
                    case TelephonyManager.NETWORK_TYPE_HSUPA:
                    case TelephonyManager.NETWORK_TYPE_HSPA:
                    case TelephonyManager.NETWORK_TYPE_EVDO_B:
                    case TelephonyManager.NETWORK_TYPE_EHRPD:
                    case TelephonyManager.NETWORK_TYPE_HSPAP:
                        netType = NetworkType.NETWORK_3G;
                        break;

                    case TelephonyManager.NETWORK_TYPE_LTE:
                    case TelephonyManager.NETWORK_TYPE_IWLAN:
                        netType = NetworkType.NETWORK_4G;
                        break;

                    case TelephonyManager.NETWORK_TYPE_GSM:
                    case TelephonyManager.NETWORK_TYPE_GPRS:
                    case TelephonyManager.NETWORK_TYPE_CDMA:
                    case TelephonyManager.NETWORK_TYPE_EDGE:
                    case TelephonyManager.NETWORK_TYPE_1xRTT:
                    case TelephonyManager.NETWORK_TYPE_IDEN:
                        netType = NetworkType.NETWORK_2G;
                        break;
                    default:
                        String subtypeName = info.getSubtypeName();
                        if (subtypeName.equalsIgnoreCase("TD-SCDMA")
                                || subtypeName.equalsIgnoreCase("WCDMA")
                                || subtypeName.equalsIgnoreCase("CDMA2000")) {
                            netType = NetworkType.NETWORK_3G;
                        } else {
                            netType = NetworkType.NETWORK_UNKNOWN;
                        }
                        break;
                }
            } else {
                netType = NetworkType.NETWORK_UNKNOWN;
            }
        }
        return netType;
    }
}

枚举类NetworkType

public enum NetworkType {
    NETWORK_WIFI("WiFi"),
    NETWORK_4G("4G"),
    NETWORK_2G("2G"),
    NETWORK_3G("3G"),
    NETWORK_UNKNOWN("Unknown"),
    NETWORK_NO("No network");

    private String desc;
    NetworkType(String desc) {
        this.desc = desc;
    }

    @Override
    public String toString() {
        return desc;
    }
}

 接口NetStateChangeObserver 

public interface NetStateChangeObserver {
    void onNetDisconnected();
    void onNetConnected(NetworkType networkType);
}

以上纯复制就好 使用

public class MainActivity extends AppCompatActivity implements NetStateChangeObserver {

    @Override
    public void onNetDisconnected() {
        // do sth
    }

    @Override
    public void onNetConnected(NetworkType networkType) {
        // do sth
    }

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        NetStateChangeReceiver.registerReceiver(this);
    }

    @Override
    protected void onDestroy() {
        NetStateChangeReceiver.unRegisterReceiver(this);
        super.onDestroy();
    }

    @Override
    protected void onResume() {
        super.onResume( );
        NetStateChangeReceiver.registerObserver(this);
    }

    @Override
    protected void onPause() {
        super.onPause( );
        NetStateChangeReceiver.unRegisterObserver(this);
    }

}