[Android]判断网络连接是否可用

	/**
	 * 判断移动网络是否开启
	 * 
	 * @param context
	 * @return
	 */
	public static boolean isNetEnabled(Context context) {
		TelephonyManager tm = (TelephonyManager) context
				.getSystemService(Context.TELEPHONY_SERVICE);
		if (tm != null) {
			if (tm.getNetworkType() != TelephonyManager.NETWORK_TYPE_UNKNOWN) {
				Log.i("sjf", "移动网络已经开启");
				return true;
			}
		}
		Log.i("sjf", "移动网络还未开启");
		return false;
	}

	/**
	 * 判断WIFI网络是否开启
	 * 
	 * @param context
	 * @return
	 */
	public static boolean isWifiEnabled(Context context) {
		WifiManager wm = (WifiManager) context
				.getSystemService(Context.WIFI_SERVICE);
		if (wm != null && wm.isWifiEnabled()) {
			Log.i("sjf", "Wifi网络已经开启");
			return true;
		}
		Log.i("sjf", "Wifi网络还未开启");
		return false;
	}

	/**
	 * 判断移动网络是否连接成功
	 * 
	 * @param context
	 * @return
	 */
	public static boolean isNetContected(Context context) {
		ConnectivityManager cm = (ConnectivityManager) context
				.getSystemService(Context.CONNECTIVITY_SERVICE);
		NetworkInfo info = cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
		if (cm != null && info != null && info.isConnected()) {
			Log.i("sjf", "移动网络连接成功");
			return true;
		}
		Log.i("sjf", "移动网络连接失败");
		return false;
	}

	/**
	 * 判断WIFI是否连接成功
	 * 
	 * @param context
	 * @return
	 */
	public static boolean isWifiContected(Context context) {
		ConnectivityManager cm = (ConnectivityManager) context
				.getSystemService(Context.CONNECTIVITY_SERVICE);
		NetworkInfo info = cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
		if (info != null && info.isConnected()) {
			Log.i("sjf", "Wifi网络连接成功");
			return true;
		}
		Log.i("sjf", "Wifi网络连接失败");
		return false;
	}

	/**
	 * 判断移动网络和WIFI是否开启
	 * 
	 * @param context
	 * @return
	 */
	public static boolean isNetWorkEnabled(Context context) {
		return (isNetEnabled(context) || isWifiEnabled(context));
	}

	/**
	 * 判断移动网络和WIFI是否连接成功
	 * @param context
	 * @return
	 */
	public static boolean isNetworkConnected(Context context) {
		return (isWifiContected(context) || isNetContected(context));
	}

操作Wifi需要AndroidManifest.xml在进行一些配置：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission>  
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>  
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>