Wi-Fi Connections
Connect with WEP encryption
This example connects to a Wi-Fi access point with WEP encryption, given an SSID and the password.
public boolean ConnectToNetworkWEP(String networkSSID, String password)
{
try {
WifiConfiguration conf = new WifiConfiguration();
conf.SSID = "\"" + networkSSID + "\""; // Please note the quotes. String should contain SSID in quotes
conf.wepKeys[0] = "\"" + password + "\""; //Try it with quotes first
conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
conf.allowedGroupCiphers.set(WifiConfiguration.AuthAlgorithm.OPEN);
conf.allowedGroupCiphers.set(WifiConfiguration.AuthAlgorithm.SHARED);
WifiManager wifiManager = (WifiManager) this.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
int networkId = wifiManager.addNetwork(conf);
if (networkId == -1){
//Try it again with no quotes in case of hex password
conf.wepKeys[0] = password;
networkId = wifiManager.addNetwork(conf);
}
List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for( WifiConfiguration i : list ) {
if(i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
wifiManager.disconnect();
wifiManager.enableNetwork(i.networkId, true);
wifiManager.reconnect();
break;
}
}
//WiFi Connection success, return true
return true;
} catch (Exception ex) {
System.out.println(Arrays.toString(ex.getStackTrace()));
return false;
}
}
Connect with WPA2 encryption
This example connects to a Wi-Fi access point with WPA2 encryption.
public boolean ConnectToNetworkWPA(String networkSSID, String password) {
try {
WifiConfiguration conf = new WifiConfiguration();
conf.SSID = "\"" + networkSSID + "\""; // Please note the quotes. String should contain SSID in quotes
conf.preSharedKey = "\"" + password + "\"";
conf.status = WifiConfiguration.Status.ENABLED;
conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
Log.d("connecting", conf.SSID + " " + conf.preSharedKey);
WifiManager wifiManager = (WifiManager) this.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
wifiManager.addNetwork(conf);
Log.d("after connecting", conf.SSID + " " + conf.preSharedKey);
List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for( WifiConfiguration i : list ) {
if(i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
wifiManager.disconnect();
wifiManager.enableNetwork(i.networkId, true);
wifiManager.reconnect();
Log.d("re connecting", i.SSID + " " + conf.preSharedKey);
break;
}
}
//WiFi Connection success, return true
return true;
} catch (Exception ex) {
System.out.println(Arrays.toString(ex.getStackTrace()));
return false;
}
}
Scan for access points
This example scans for available access points and ad hoc networks. btnScan
activates a scan initiated by the WifiManager.startScan()
method. After the scan, WifiManager
calls the SCAN_RESULTS_AVAILABLE_ACTION
intent and the WifiScanReceiver
class processes the scan result. The results are displayed in a TextView
.
public class MainActivity extends AppCompatActivity {
private final static String TAG = "MainActivity";
TextView txtWifiInfo;
WifiManager wifi;
WifiScanReceiver wifiReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
wifi=(WifiManager)getSystemService(Context.WIFI_SERVICE);
wifiReceiver = new WifiScanReceiver();
txtWifiInfo = (TextView)findViewById(R.id.txtWifiInfo);
Button btnScan = (Button)findViewById(R.id.btnScan);
btnScan.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG, "Start scan...");
wifi.startScan();
}
});
}
protected void onPause() {
unregisterReceiver(wifiReceiver);
super.onPause();
}
protected void onResume() {
registerReceiver(
wifiReceiver,
new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)
);
super.onResume();
}
private class WifiScanReceiver extends BroadcastReceiver {
public void onReceive(Context c, Intent intent) {
List<ScanResult> wifiScanList = wifi.getScanResults();
txtWifiInfo.setText("");
for(int i = 0; i < wifiScanList.size(); i++){
String info = ((wifiScanList.get(i)).toString());
txtWifiInfo.append(info+"\n\n");
}
}
}
}
Permissions
The following permissions need to be defined in AndroidManifest.xml:
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
android.permission.ACCESS_WIFI_STATE
is necessary for calling WifiManager.getScanResults()
. Without android.permission.CHANGE_WIFI_STATE
you cannot initiate a scan with WifiManager.startScan()
.
When compiling the project for api level 23 or greater (Android 6.0 and up), either android.permission.ACCESS_FINE_LOCATION
or android.permission.ACCESS_COARSE_LOCATION
must be inserted. Furthermore that permission needs to be requested, e.g. in the onCreate
method of your main activity:
@Override
protected void onCreate(Bundle savedInstanceState) {
...
String[] PERMS_INITIAL={
Manifest.permission.ACCESS_FINE_LOCATION,
};
ActivityCompat.requestPermissions(this, PERMS_INITIAL, 127);
}