I am using the following TCPListener in Xamarin.Android that has served me well in the past, but only have one problem with it...
In the following piece of code within startListener() (Full code below)
while (!NS.DataAvailable && sta)
{
System.Threading.Thread.Sleep(50);
if (cntr > 20)
{
TCPC.Close();
NS = null;
break;
}
cntr++;
}
The TCPClient gets closed if the NetworkSteam has not data to Send(Reply) or Receive for a period of time, which is not a problem and do need it to close this.
Problem is that I can set this "timeout" between changing Thread.Sleep(50) value and cntr > 20 value, but becomes very difficult to predict how long this timeout needs to be depending on what data was received, as I need to perform long running operations on the data before sending the reply (long running as in could be 3sec or 30sec), if I set it too short then it closes my TCP client before I am able to reply, if I set it too long the port is blocked for many seconds after sending the reply and I cannot send the next command until this timeout has expired. Is there a better way to handle this timeout, or a better implementation not using TCPListener
private static void startListener()
{
ListenStarted = true;
TCPL = new TcpListener(IPAddress.Any, 8012);
try
{
TCPL.Start();
sta = true;
}
catch (Exception e)
{
//Log Error
}
while (sta)
{
try
{
TCPC = TCPL.AcceptTcpClient();
TCPC.NoDelay = true;
NS = TCPC.GetStream();
while (NS.CanRead && NS.CanWrite && sta)
{
StringBuilder sb = new StringBuilder();
int cntr = 0;
while (!NS.DataAvailable && sta)
{
System.Threading.Thread.Sleep(50);
if (cntr > 20)
{
TCPC.Close();
NS = null;
break;
}
cntr++;
}
if (NS == null)
break;
while (NS.DataAvailable && sta)
{
int bte = NS.ReadByte();
if (bte == -1)
break;
if ((char)bte != (char)0x03)
{
sb.Append((char)bte);
}
else
{
processDataSets(sb);
break;
}
}
}
}
catch (Exception e)
{
sta = false;
}
}
ListenStarted = false;
NS = null;
}
I made a project Led on/offbut with 5 leds. I send strings to arduino bluetooth for on or off leds. But i need led on only some leds. For example i wont led on pin 10 and pin 9. But Before on pin 12 i can't on pin 11, and before off pin 12 i can't off another pins? Why? I put my code here:
For arduino:
while(Serial.available() > 0)
{
command = ((byte)Serial.read());
if(command == ':')
{
break;
}
else
{
string += command;
}
delay(1);
}
if(string == "A")
{
ledOn();// ledOn(){analogWrite(led, 255); delay(10);}
}
if(string =="B")
{
ledOff();
}
if(string == "C")
{
ledOnB();
}
if(string =="D")
{
ledOffB();
}
if(string == "E")
{
ledOnC();
}
if(string =="F")
{
ledOffC();
}
if(string =="G")
{
ledOnD();
}
if(string =="H")
{
ledOffD();
}
if(string == "I")
{
ledOnE();
}
if(string =="J")
{
ledOffE();
}
I have a button in MainActivity which is used to write a byte[] to BLE device:
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Write Char"
android:id="#+id/button2"
android:onClick="onClickWrite" />
And the function onClickWrite is
public void onClickWrite(View v){
if(mBluetoothLeService != null) {
byte [] data= new byte[3];
data[0] = (byte)(0 & 0xFF);
data[1] = (byte)(255 & 0xFF);
data[2] = (byte)(0 & 0xFF);
mBluetoothLeService.sendData(data);
}
}
where sendData is a modified function in class [BluetoothLeService][1]. It worked well when I press the button. However, Let is careful to look at the sendData function. It searches service and Characteristic again when I press the button. Is it correct procedure for write a Characteristic in BLE?
public void sendData(byte[] data){
String lService = "00001c00-d102-11e1-9b23-00025b00a5A5";
String lCharacteristic = "00001c03-d102-11e1-9b23-00025b00a5a5";
BluetoothGattService mBluetoothLeService = null;
BluetoothGattCharacteristic mBluetoothGattCharacteristic = null;
for (BluetoothGattService service : mBluetoothGatt.getServices()) {
if ((service == null) || (service.getUuid() == null)) {
Log.d("TAG","Something is null");
continue;
}
if (lService.equalsIgnoreCase(service.getUuid().toString())) {
Log.d("TAG","service.getUuid().toString()="+service.getUuid().toString());
mBluetoothLeService = service;
}
}
if(mBluetoothLeService!=null) {
mBluetoothGattCharacteristic =
mBluetoothLeService.getCharacteristic(UUID.fromString(lRgbCharacteristic));
}
else{
Log.d("TAG","mBluetoothLeService is null");
}
if(mBluetoothGattCharacteristic!=null) {
mBluetoothGattCharacteristic.setValue(data);
boolean write = mBluetoothGatt.writeCharacteristic(mBluetoothGattCharacteristic);
Log.d("TAG","writeCharacteristic:"+write);
}
else{
Log.d("TAG", "mBluetoothGattCharacteristic is null");
}
}
Yes.
(filling unnecessarily required length)
I am using CSipSimple for adding a new feature which is transfer call . For this feature I need the callID of call .
I am seeing that when I call ,the following function is called .
public void placeCallWithOption(Bundle b) {
if (service == null) {
return;
}
String toCall = "";
Long accountToUse = SipProfile.INVALID_ID;
// Find account to use
SipProfile acc = accountChooserButton.getSelectedAccount();
if(acc == null) {
return;
}
accountToUse = acc.id;
// Find number to dial
toCall = digits.getText().toString();
if(isDigit) {
toCall = PhoneNumberUtils.stripSeparators(toCall);
}
if(accountChooserFilterItem != null && accountChooserFilterItem.isChecked()) {
toCall = rewriteNumber(toCall);
}
if (TextUtils.isEmpty(toCall)) {
return;
}
// Well we have now the fields, clear theses fields
digits.getText().clear();
// -- MAKE THE CALL --//
if (accountToUse >= 0) {
// It is a SIP account, try to call service for that
try {
service.makeCallWithOptions(toCall, accountToUse.intValue(), b);
// service.xfer(callId,"01628105601");
} catch (RemoteException e) {
Log.e(THIS_FILE, "Service can't be called to make the call");
}
} else if (accountToUse != SipProfile.INVALID_ID) {
// It's an external account, find correct external account
CallHandlerPlugin ch = new CallHandlerPlugin(getActivity());
ch.loadFrom(accountToUse, toCall, new OnLoadListener() {
#Override
public void onLoad(CallHandlerPlugin ch) {
placePluginCall(ch);
}
});
}
}
But from this , I can't get callId of the call. How can I get callId of each call ? Any advice is of great help .
Using SipCallSession to fetch a call id
SipCallSession callInfo = new SipCallSession();
callinfo.getCallid();
I'm developing an app that gets the MAC address of the device, but since Android 6.0 my code doesn't work, giving me an incorrect value.
Here's my code...
public String ObtenMAC()
{
WifiManager manager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo info = manager.getConnectionInfo();
return(info.getMacAddress().toUpperCase());
}
Instead of the real MAC address, it returns an strange code: 02:00:00:00:00:00.
Please refer to Android 6.0 Changes.
To provide users with greater data protection, starting in this release, Android removes programmatic access to the device’s local hardware identifier for apps using the Wi-Fi and Bluetooth APIs. The WifiInfo.getMacAddress() and the BluetoothAdapter.getAddress() methods now return a constant value of 02:00:00:00:00:00.
To access the hardware identifiers of nearby external devices via Bluetooth and Wi-Fi scans, your app must now have the ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION permissions.
Use below code to get Mac address in Android 6.0
public static String getMacAddr() {
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (!nif.getName().equalsIgnoreCase("wlan0")) continue;
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(Integer.toHexString(b & 0xFF) + ":");
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
} catch (Exception ex) {
//handle exception
}
return "";
}
I didn't get the above answer to work, but stumbled upon another answer.
Here is a complete and simple method on getting the IPv6 address and then getting the mac address from it.
How to get Wi-Fi Mac address in Android Marshmallow
public static String getMacAddr() {
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (!nif.getName().equalsIgnoreCase("wlan0")) continue;
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(String.format("%02X:",b));
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
} catch (Exception ex) {
}
return "02:00:00:00:00:00";
}
Tested it already and it works. Many thanks to Rob Anderson!
this is the complete 2 ways code of getting it successfully on Marshmallow , just copy past this and it will work !
//Android 6.0 : Access to mac address from WifiManager forbidden
private static final String marshmallowMacAddress = "02:00:00:00:00:00";
private static final String fileAddressMac = "/sys/class/net/wlan0/address";
public static String recupAdresseMAC(WifiManager wifiMan) {
WifiInfo wifiInf = wifiMan.getConnectionInfo();
if(wifiInf.getMacAddress().equals(marshmallowMacAddress)){
String ret = null;
try {
ret= getAdressMacByInterface();
if (ret != null){
return ret;
} else {
ret = getAddressMacByFile(wifiMan);
return ret;
}
} catch (IOException e) {
Log.e("MobileAccess", "Erreur lecture propriete Adresse MAC");
} catch (Exception e) {
Log.e("MobileAcces", "Erreur lecture propriete Adresse MAC ");
}
} else{
return wifiInf.getMacAddress();
}
return marshmallowMacAddress;
}
private static String getAdressMacByInterface(){
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (nif.getName().equalsIgnoreCase("wlan0")) {
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(String.format("%02X:",b));
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
}
} catch (Exception e) {
Log.e("MobileAcces", "Erreur lecture propriete Adresse MAC ");
}
return null;
}
private static String getAddressMacByFile(WifiManager wifiMan) throws Exception {
String ret;
int wifiState = wifiMan.getWifiState();
wifiMan.setWifiEnabled(true);
File fl = new File(fileAddressMac);
FileInputStream fin = new FileInputStream(fl);
StringBuilder builder = new StringBuilder();
int ch;
while((ch = fin.read()) != -1){
builder.append((char)ch);
}
ret = builder.toString();
fin.close();
boolean enabled = WifiManager.WIFI_STATE_ENABLED == wifiState;
wifiMan.setWifiEnabled(enabled);
return ret;
}
manifest :
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
Summary : this code will try to get the MAC address first by Interface and if its failed it get it by file system.
Note:for file System way, you need to enable WIFI to access the file.
thnx to Sam's answer here https://stackoverflow.com/a/39288868/3818437
You can get the MAC address from the IPv6 local address. E.g., the IPv6 address "fe80::1034:56ff:fe78:9abc" corresponds to the MAC address "12-34-56-78-9a-bc". See the code below. Getting the WiFi IPv6 address only requires android.permission.INTERNET.
See the Wikipedia page IPv6 address, particularly the note about "local addresses" fe80::/64 and the section about "Modified EUI-64".
/**
* Gets an EUI-48 MAC address from an IPv6 link-local address.
* E.g., the IPv6 address "fe80::1034:56ff:fe78:9abc"
* corresponds to the MAC address "12-34-56-78-9a-bc".
* <p/>
* See the note about "local addresses" fe80::/64 and the section about "Modified EUI-64" in
* the Wikipedia article "IPv6 address" at https://en.wikipedia.org/wiki/IPv6_address
*
* #param ipv6 An Inet6Address object.
* #return The EUI-48 MAC address as a byte array, null on error.
*/
private static byte[] getMacAddressFromIpv6(final Inet6Address ipv6)
{
byte[] eui48mac = null;
if (ipv6 != null) {
/*
* Make sure that this is an fe80::/64 link-local address.
*/
final byte[] ipv6Bytes = ipv6.getAddress();
if ((ipv6Bytes != null) &&
(ipv6Bytes.length == 16) &&
(ipv6Bytes[0] == (byte) 0xfe) &&
(ipv6Bytes[1] == (byte) 0x80) &&
(ipv6Bytes[11] == (byte) 0xff) &&
(ipv6Bytes[12] == (byte) 0xfe)) {
/*
* Allocate a byte array for storing the EUI-48 MAC address, then fill it
* from the appropriate bytes of the IPv6 address. Invert the 7th bit
* of the first byte and discard the "ff:fe" portion of the modified
* EUI-64 MAC address.
*/
eui48mac = new byte[6];
eui48mac[0] = (byte) (ipv6Bytes[8] ^ 0x2);
eui48mac[1] = ipv6Bytes[9];
eui48mac[2] = ipv6Bytes[10];
eui48mac[3] = ipv6Bytes[13];
eui48mac[4] = ipv6Bytes[14];
eui48mac[5] = ipv6Bytes[15];
}
}
return eui48mac;
}
I try to get mac address with 2 methods, first by Interface and if its failed, i get it by file system, but you need to enable wifi to access the file.
//Android 6.0 : Access to mac address from WifiManager forbidden
private static final String marshmallowMacAddress = "02:00:00:00:00:00";
private static final String fileAddressMac = "/sys/class/net/wlan0/address";
public static String recupAdresseMAC(WifiManager wifiMan) {
WifiInfo wifiInf = wifiMan.getConnectionInfo();
if(wifiInf.getMacAddress().equals(marshmallowMacAddress)){
String ret = null;
try {
ret= getAdressMacByInterface();
if (ret != null){
return ret;
} else {
ret = getAddressMacByFile(wifiMan);
return ret;
}
} catch (IOException e) {
Log.e("MobileAccess", "Erreur lecture propriete Adresse MAC");
} catch (Exception e) {
Log.e("MobileAcces", "Erreur lecture propriete Adresse MAC ");
}
} else{
return wifiInf.getMacAddress();
}
return marshmallowMacAddress;
}
private static String getAdressMacByInterface(){
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (nif.getName().equalsIgnoreCase("wlan0")) {
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(String.format("%02X:",b));
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
}
} catch (Exception e) {
Log.e("MobileAcces", "Erreur lecture propriete Adresse MAC ");
}
return null;
}
private static String getAddressMacByFile(WifiManager wifiMan) throws Exception {
String ret;
int wifiState = wifiMan.getWifiState();
wifiMan.setWifiEnabled(true);
File fl = new File(fileAddressMac);
FileInputStream fin = new FileInputStream(fl);
ret = convertStreamToString(fin);
fin.close();
boolean enabled = WifiManager.WIFI_STATE_ENABLED == wifiState;
wifiMan.setWifiEnabled(enabled);
return ret;
}
Add this line to your manifest.
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
I recommend you to persist your mac address in your preferences like here
mac = activity.getSharedPreferences("MAC_ADDRESS", Context.MODE_PRIVATE).getString("MAC_ADDRESS", "");
if(mac == null || mac.equals("")){
WifiManager wifiMan = (WifiManager) activity.getSystemService(Context.WIFI_SERVICE);
mac = MobileAccess.recupAdresseMAC(wifiMan);
if(mac != null && !mac.equals("")){
SharedPreferences.Editor editor = activity.getSharedPreferences("MAC_ADDRESS", Context.MODE_PRIVATE).edit();
editor.putString("MAC_ADDRESS", mac).commit();
}
}
Its Perfectly Fine
package com.keshav.fetchmacaddress;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Collections;
import java.util.List;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.e("keshav","getMacAddr -> " +getMacAddr());
}
public static String getMacAddr() {
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (!nif.getName().equalsIgnoreCase("wlan0")) continue;
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(Integer.toHexString(b & 0xFF) + ":");
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
} catch (Exception ex) {
//handle exception
}
return "";
}
}
First you need to add Internet user permission.
<uses-permission android:name="android.permission.INTERNET" />
Then you can find the mac over the NetworkInterfaces API.
public static String getMacAddr() {
try {
List<NetworkInterface> all = Collections.list(NetworkInterface.getNetworkInterfaces());
for (NetworkInterface nif : all) {
if (!nif.getName().equalsIgnoreCase("wlan0")) continue;
byte[] macBytes = nif.getHardwareAddress();
if (macBytes == null) {
return "";
}
StringBuilder res1 = new StringBuilder();
for (byte b : macBytes) {
res1.append(String.format("%02X:",b));
}
if (res1.length() > 0) {
res1.deleteCharAt(res1.length() - 1);
}
return res1.toString();
}
} catch (Exception ex) {
}
return "02:00:00:00:00:00";
}
The answers are mostly correct, but keep care, that there is a change in android 7. You will need to use the
DevicePolicyManager and the Method getWifiMacAddress. The official docs has a typo, which means that you shouldnt copy/paste it from there.
DevicePolicyManager.getWifiMacAddress()
Refs:
https://developer.android.com/about/versions/nougat/android-7.0-changes.html
Get Device mac adress in Android Nougat and O programmatically
Use wifiInfo.getBSSID() to get Mac Address of AccessPoint instead of getMacAddress method.
This is a more kotlin way to get Mac Address
fun getMacAddress(): String =
NetworkInterface.getNetworkInterfaces().toList()
.firstOrNull { it.name.equals("wlan0", ignoreCase = true) }?.let {
it.hardwareAddress?.let { macBytes ->
StringBuilder().apply {
for (b in macBytes) {
append(String.format("%02X:", b))
}
if (isNotEmpty()) {
deleteCharAt(lastIndex)
}
}
}.toString()
} ?: "02:00:00:00:00:00"