android 是否联网 判断 （网络连接）

ConnectivityManager cwjManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info = cwjManager.getActiveNetworkInfo();
if (info != null && info.isAvailable()) {
// do something
// 能联网
Toast.makeText(WohotelPhoneActivity.this, "已经连网", Toast.LENGTH_LONG)
.show();
System.out.println("=======================已连网");
} else {
// do something
// 不能联网
Toast.makeText(WohotelPhoneActivity.this, "未连网", Toast.LENGTH_LONG)
.show();
System.out.println("=======================未连网");
}

｝

最后别忘记添加网络权限： <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>