Android 判斷網絡是否可用、網絡類型WIFI/2G/3G/4G及獲取IP

1. 在AndroidManifest.xml中添加訪問當前網絡狀態權限

    <!-- 訪問當前網絡狀態權限 -->
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" >
    </uses-permission>

2. 添加代碼

檢查當前網絡是否可用

public class LoginActivity extends Activity {
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		if (isNetworkAvailable(LoginActivity.this)) {
			Toast.makeText(getApplicationContext(), "當前有可用網絡！",
					Toast.LENGTH_LONG).show();
		} else {
			Toast.makeText(getApplicationContext(), "當前沒有可用網絡！",
					Toast.LENGTH_LONG).show();
		}
	}

	/**
	 * 檢查當前網絡是否可用
	 * 
	 * @param context
	 * @return
	 */

	public boolean isNetworkAvailable(Activity activity) {
		Context context = activity.getApplicationContext();
		// 獲取手機所有連接管理對象（包括對wi-fi,net等連接的管理）
		ConnectivityManager connectivityManager = (ConnectivityManager) context
				.getSystemService(Context.CONNECTIVITY_SERVICE);

		if (connectivityManager == null) {
			return false;
		} else {
			// 獲取NetworkInfo對象
			NetworkInfo[] networkInfo = connectivityManager.getAllNetworkInfo();

			if (networkInfo != null && networkInfo.length > 0) {
				for (int i = 0; i < networkInfo.length; i++) {
					// 判斷當前網絡狀態是否爲連接狀態
					if (networkInfo[i].getState() == NetworkInfo.State.CONNECTED) {
						return true;
					}
				}
			}
		}
		return false;
	}
}

3. 判斷手機網絡類型

 ConnectivityManager connectMgr = (ConnectivityManager) this
        .getSystemService(Context.CONNECTIVITY_SERVICE);
 
 NetworkInfo info = connectMgr.getActiveNetworkInfo();
 
一、判斷網絡是否是wifi，在判斷之前一定要進行的非空判斷，如果沒有任何網絡
連接info ==null
info.getType() == ConnectivityManager.TYPE_WIFI
 
二、判斷是否是手機網絡
info !=null && info.getType() ==  ConnectivityManager.TYPE_MOBILE
 
手機網絡進行詳細區分：
 
info.getSubtype() 這裏使用 getSubtype()，不是 getType()，getType()返回的
是0，或者1，是區分是手機網絡還是wifi
 
info.getSubtype()取值列表如下：

case NETWORK_TYPE_GPRS:
case NETWORK_TYPE_EDGE:
case NETWORK_TYPE_CDMA:
case NETWORK_TYPE_1xRTT:
case NETWORK_TYPE_IDEN:
return NETWORK_CLASS_2_G;

case NETWORK_TYPE_UMTS:
case NETWORK_TYPE_EVDO_0:
case NETWORK_TYPE_EVDO_A:
case NETWORK_TYPE_HSDPA:
case NETWORK_TYPE_HSUPA:
case NETWORK_TYPE_HSPA:
case NETWORK_TYPE_EVDO_B:
case NETWORK_TYPE_EHRPD:
case NETWORK_TYPE_HSPAP:
return NETWORK_CLASS_3_G;

case NETWORK_TYPE_LTE:
return NETWORK_CLASS_4_G;

GPRS        2G(2.5) General Packet Radia Service 114kbps
EDGE        2G(2.75G) Enhanced Data Rate for GSM Evolution 384kbps
IDEN          2G Integrated Dispatch Enhanced Networks 集成數字增強型網絡
CDMA        2G 電信 Code Division Multiple Access 碼分多址
1xRTT        2G CDMA2000 1xRTT (RTT - 無線電傳輸技術) 144kbps 2G的過渡,

EVDO_B    3G EV-DO Rev.B 14.7Mbps 下行 3.5G
EHRPD      3G CDMA2000向LTE 4G的中間產物 Evolved High Rate Packet Data HRPD的升級
HSPA         3G (分HSDPA,HSUPA) High Speed Packet Access 
HSPAP       3G HSPAP 
UMTS        3G WCDMA 聯通3G Universal Mobile Telecommunication System 完整的3G移動通信技術標準
EVDO_0    3G (EVDO 全程 CDMA2000 1xEV-DO) Evolution - Data Only (Data Optimized) 153.6kps - 2.4mbps 屬於3G
EVDO_A    3G 1.8mbps - 3.1mbps 屬於3G過渡，3.5G

HSDPA      3.5G 高速下行分組接入 3.5G WCDMA High Speed Downlink Packet Access 14.4mbps 
HSUPA      3.5G High Speed Uplink Packet Access 高速上行鏈路分組接入 1.4 - 5.8 mbps

LTE            4G Long Term Evolution FDD-LTE 和 TDD-LTE , 3G過渡，升級版 LTE Advanced 纔是4G 

4. Android獲取手機IP

private String getPhoneIp() {
        try {  
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {  
                NetworkInterface intf = en.nextElement();  
                for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {  
                    InetAddress inetAddress = enumIpAddr.nextElement();  
                    if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {  
                    //if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet6Address) {  
                        return inetAddress.getHostAddress().toString();  
                    }  
                }  
            }  
        } catch (Exception e) {  
        }  
        return ""; 
    }