Android判断网络状态是否断开

/**
* 退出程序(关闭所有当前运行程序所有的Activity)
*/
public void exit(){
//<uses-permission android:name="android.permission.RESTART_PACKAGES"></uses-permission>
ActivityManager actManager = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
actManager.restartPackage(getPackageName());
}

public Boolean getNetworkIsAvailable(){
//此处写网络检测的代码
//<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
ConnectivityManager conManager=(ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE );
NetworkInfo networkInfo = conManager.getActiveNetworkInfo();
if (networkInfo != null ){
return networkInfo.isAvailable();
}
return false ;
}