Android
Wi-Fi 연결

WEP 암호화 연결

이 예에서는 SSID와 암호가 주어지면 WEP 암호화를 사용하여 Wi-Fi 액세스 포인트에 연결합니다.

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;
    }
}

WPA2 암호화로 연결

이 예는 WPA2 암호화를 사용하여 Wi-Fi 액세스 지점에 연결합니다.

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;
  }
}

액세스 포인트 스캔

이 예에서는 사용 가능한 액세스 포인트 및 Ad Hoc 네트워크를 검색합니다. btnScan 은 WifiManager.startScan() 메소드에 의해 시작된 검사를 활성화합니다. 검사가 WifiManager 는 SCAN_RESULTS_AVAILABLE_ACTION 텐트를 호출하고 WifiScanReceiver 클래스는 검사 결과를 처리합니다. 결과는 TextView 표시됩니다.

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");
            }
        }
    }
}

권한

AndroidManifest.xml에 다음 권한을 정의해야합니다.

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

WifiManager.getScanResults() 를 호출 WifiManager.getScanResults() android.permission.ACCESS_WIFI_STATE 가 필요합니다. android.permission.CHANGE_WIFI_STATE 없이는 WifiManager.startScan() 하여 검사를 시작할 수 없습니다.

23 레벨 이상의 API (Android 6.0 이상)를 컴파일 할 때 android.permission.ACCESS_FINE_LOCATION 또는 android.permission.ACCESS_COARSE_LOCATION 을 삽입해야합니다. 또한, 예를 들어 주요 활동의 onCreate 메소드에서 권한을 요청해야합니다.

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    String[] PERMS_INITIAL={
            Manifest.permission.ACCESS_FINE_LOCATION,
    };
    ActivityCompat.requestPermissions(this, PERMS_INITIAL, 127);
}