我编写了一个代码，它使用互联网将数据插入到我的数据库中，但是如果与互联网的连接不可用，如果数据库不为空，我的应用程序会从数据库中获取数据。
如何编写代码来检查我的应用程序的 Internet 连接性？
问问题
296 次
6 回答
2
使用以下代码检查互联网。
public boolean check_Internet(Context mContext) {
ConnectivityManager mConnectivityManager = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mNetworkInfo = mConnectivityManager.getActiveNetworkInfo();
if (mNetworkInfo != null && mNetworkInfo.isConnectedOrConnecting())
return true;
else
return false;
}
还要在 AndroidManifest.xml 文件中添加以下权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
于 2013-08-14T11:58:44.520 回答
2
我有一个网络工具给你。
public final class NetworkUtils {
public static final byte CONNECTION_OFFLINE = 1;
public static final byte CONNECTION_WIFI = 2;
public static final byte CONNECTION_ROAMING = 3;
public static final byte CONNECTION_SLOW = 4;
public static final byte CONNECTION_FAST = 5;
private static String sUserId;
private NetworkUtils() {}
/**
* Check if the device is connected to the internet (mobile network or
* WIFI).
*/
public static boolean isOnline(Context _context) {
boolean online = false;
TelephonyManager tmanager = (TelephonyManager) _context.getSystemService(Context.TELEPHONY_SERVICE);
if (tmanager != null) {
if (tmanager.getDataState() == TelephonyManager.DATA_CONNECTED) {
// Mobile network
online = true;
} else {
// WIFI
ConnectivityManager cmanager = (ConnectivityManager) _context
.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cmanager != null) {
NetworkInfo info = cmanager.getActiveNetworkInfo();
if (info != null)
online = info.isConnected();
}
}
}
return online;
}
/**
* Get the User Agent String in the format
* AppName + AppVersion + Model + ReleaseVersion + Locale
*/
public static String getUserAgentString(Context _c, String _appName) {
if(_appName == null)
_appName = "";
String agent = _appName + " " + BackendUtil.getAppVersionString(_c) + " (" + Build.MODEL + "; Android "
+ Build.VERSION.RELEASE + "; " + Locale.getDefault() + ")";
if(agent.startsWith(" "))
agent = agent.substring(1);
return agent;
}
/**
* Evaluate the current network connection and return the
* corresponding type, e.g. CONNECTION_WIFI.
*/
public static byte getCurrentNetworkType(Context _context){
NetworkInfo netInfo = ((ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
if(netInfo == null)
return CONNECTION_OFFLINE;
if(netInfo.getType() == ConnectivityManager.TYPE_WIFI)
return CONNECTION_WIFI;
if(netInfo.isRoaming())
return CONNECTION_ROAMING;
if(!(netInfo.getType() == ConnectivityManager.TYPE_MOBILE
&& (netInfo.getSubtype() == TelephonyManager.NETWORK_TYPE_UMTS
|| netInfo.getSubtype() == TelephonyManager.NETWORK_TYPE_HSDPA
|| netInfo.getSubtype() == TelephonyManager.NETWORK_TYPE_HSUPA
|| netInfo.getSubtype() == TelephonyManager.NETWORK_TYPE_HSPA
|| netInfo.getSubtype() == 13 // NETWORK_TYPE_LTE
|| netInfo.getSubtype() == 15))) // NETWORK_TYPE_HSPAP
{
return CONNECTION_SLOW;
}
return CONNECTION_FAST;
}
/**
* Return the current IP adresse of the device or null if it could not be
* found.
*/
public static String getIpAdress() {
String result = null;
try {
for (Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces(); interfaces.hasMoreElements();) {
NetworkInterface iface = interfaces.nextElement();
for (Enumeration<InetAddress> adresses = iface.getInetAddresses(); adresses.hasMoreElements();) {
InetAddress ip = adresses.nextElement();
if (!ip.isLoopbackAddress())
result = ip.getHostAddress();
}
}
} catch (SocketException _e) {
LL.error("Could not find device's ip adress");
}
return result;
}
/**
* Return a MD5 hash of the device id.
*/
public static synchronized String getUserId(Context _context) {
if (sUserId == null) {
TelephonyManager tm = (TelephonyManager) _context.getSystemService(Context.TELEPHONY_SERVICE);
String id = tm.getDeviceId();
try {
MessageDigest digester = MessageDigest.getInstance("MD5");
digester.update(id.getBytes());
byte[] digest = digester.digest();
// Convert to hex string
BigInteger converter = new BigInteger(1, digest);
String md5 = converter.toString(16);
while (md5.length() < 32)
md5 = "0" + md5;
sUserId = md5;
} catch (NoSuchAlgorithmException _e) {
LL.error("Could not find MD5");
}
}
return sUserId;
}
}
于 2013-08-14T12:04:12.103 回答
1
if (InetAddress.getByName("www.google.com").isReachable(2000)){ // 2000 = timeout
// connection is available. google is a good candidate
} else {
// no connection
}
于 2013-08-14T11:59:25.177 回答
1
于 2013-08-14T12:05:14.867 回答
1
Boolean online = isOnline();
if (online == false) {
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
context);
// set title
alertDialogBuilder.setTitle("Cellular Data is Turned Off!");
// set dialog message
alertDialogBuilder
.setMessage(
"Please turn on cellular data or use Wi-Fi to access data!")
.setCancelable(false)
.setNeutralButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
startActivity(new Intent(
android.provider.Settings.ACTION_WIRELESS_SETTINGS));
}
})
.setPositiveButton("Ok",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int id) {
dialog.cancel();
}
});
// create alert dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// show it
alertDialog.show();
于 2013-08-14T12:07:22.643 回答
1
创建如下方法：
public boolean checkInternet() {
ConnectivityManager conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
State mobile = conMan.getNetworkInfo(0).getState();
State wifi = conMan.getNetworkInfo(1).getState();
if (mobile == NetworkInfo.State.CONNECTED || wifi== NetworkInfo.State.CONNECTED)
return true;
else
return false;
}
在 Activity 或 Service 中，您可以这样做：
if(CheckInternet)
{
// do your work
}
else
{
Thread t = new Thread() {
@Override
public void run() {
try
{
//check if connected!
while (!checkInternet())
{
//Wait to connect
Thread.sleep(5000);
}
//do Your Work here
} catch (Exception e) {
}
}
};
t.start();
}
还要在 AndroidManifest.xml 文件中添加以下权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
于 2013-08-14T12:10:38.890 回答