请教个问题，网络编程怎么获取用的mac地址（网页中），请高手指教
mac地址好像在机器上是可以修改的，修改以后在网页中获取的是修改以后的吗？

------解决方案--------------------
你是怎么获取的
------解决方案--------------------
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;



public class TestMac
{
public static void main(String[] args) {
System.out.println("Operation System=" + getOsName());
System.out.println("Mac Address=" + getMACAddress());
System.out.println("通过ip获取mac"+getMACAddress("192.168.1.101"));
}

public static String getOsName() {
String os = "";
os = System.getProperty("os.name");
return os;
}

public static String getMACAddress() {
String address = "";
String os = getOsName();
if (os.startsWith("Windows")) {
try {
String command = "cmd.exe /c ipconfig /all";
Process p = Runtime.getRuntime().exec(command);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
if (line.indexOf("Physical Address") > 0) {
int index = line.indexOf(":");
index += 2;
address = line.substring(index);
break;
}
}
br.close();
return address.trim();
} catch (IOException e) {
}
} else if (os.startsWith("Linux")) {
String command = "/bin/sh -c ifconfig -a";
Process p;
try {
p = Runtime.getRuntime().exec(command);
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
if (line.indexOf("HWaddr") > 0) {
int index = line.indexOf("HWaddr") + "HWaddr".length();
address = line.substring(index);
break;
}
}
br.close();
} catch (IOException e) {
}
}
address = address.trim();
return address;
}



public static String getMACAddress(String ipAddress) { 
String str = "", strMAC = "", macAddress = ""; 
try { 
Process pp = Runtime.getRuntime().exec("nbtstat -a " + ipAddress); 
InputStreamReader ir = new InputStreamReader(pp.getInputStream()); 
LineNumberReader input = new LineNumberReader(ir); 
for (int i = 1; i < 100; i++) { 
str = input.readLine(); 
if (str != null) { 
if (str.indexOf("MAC Address") > 1) { 
strMAC = str.substring(str.indexOf("MAC Address") + 14, 
str.length()); 
break; 
} 
} 
} 
} catch (IOException ex) { 
return "Can't Get MAC Address!"; 
} 
// 
if (strMAC.length() < 17) { 
return "Error!"; 
} 

macAddress = strMAC.substring(0, 2) + ":" + strMAC.substring(3, 5) 
+ ":" + strMAC.substring(6, 8) + ":" + strMAC.substring(9, 11)