检查网络是否可用（Android）

<pre name="code" class="java">public class NetUtil {

/** 检查是否有网络 */
public static boolean isNetworkAvailable(Context context) {
NetworkInfo info = getNetworkInfo(context);
if (info != null) {
return info.isAvailable();
}
return false;
}

/** 检查是否是WIFI */
public static boolean isWifi(Context context) {
NetworkInfo info = getNetworkInfo(context);
if (info != null) {
if (info.getType() == ConnectivityManager.TYPE_WIFI)
return true;
}
return false;
}

/** 检查是否是移动网络 */
public static boolean isMobile(Context context) {
NetworkInfo info = getNetworkInfo(context);
if (info != null) {
if (info.getType() == ConnectivityManager.TYPE_MOBILE)
return true;
}
return false;
}

private static NetworkInfo getNetworkInfo(Context context) {

ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
return cm.getActiveNetworkInfo();
}
}