java獲取電腦的MAC值

//根據IP地址 獲取mac值

package sz.sun.cn.web.mobile;


import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Arrays;


import javax.servlet.http.HttpServletRequest;
  
/** 
 * 主機A向主機B發送“UDP－NetBIOS－NS”詢問包，即向主機B的137端口，發Query包來詢問主機B的NetBIOS Names信息。 
 * 其次，主機B接收到“UDP－NetBIOS－NS”詢問包，假設主機B正確安裝了NetBIOS服務........... 而且137端口開放，則主機B會向主機A發送一個“UDP－NetBIOS－NS”應答包，即發Answer包給主機A。 
 * 並利用UDP(NetBIOS Name Service)來快速獲取遠程主機MAC地址的方法 
 *  
 */  
public class UdpGetClientMacAddr {  
    private String sRemoteAddr;  //用戶的ip地址
    private int iRemotePort=137;//交互端口 
    private byte[] buffer = new byte[1024];//用於緩衝數據
    private DatagramSocket ds=null;  
  
    public UdpGetClientMacAddr(String strAddr) throws Exception{  
        sRemoteAddr = strAddr;  
        ds = new DatagramSocket();  
    }  
  
    public final DatagramPacket send(final byte[] bytes) throws IOException {  
        DatagramPacket dp = new DatagramPacket(bytes,bytes.length,InetAddress.getByName(sRemoteAddr),iRemotePort);  
        ds.send(dp);  
        return dp;  
    }  
  /**
   * 將需要發送的數據放入啓動的協議中進行發送
   * @return 數據包
   * @throws Exception
   */
    public final DatagramPacket receive() throws Exception {  
        DatagramPacket dp = new DatagramPacket(buffer,buffer.length);  
        ds.receive(dp);  
        return dp;  
    }  
    /**
     * 生成一個 長度爲50的字節數組
     * @return 返回一個長度爲50的byte數組
     * @throws Exception
     */
    
public byte[] GetQueryCmd() throws Exception {  
        byte[] t_ns = new byte[50];  
        t_ns[0] = 0x00;  
        t_ns[1] = 0x00;  
        t_ns[2] = 0x00;  
        t_ns[3] = 0x10;  
        t_ns[4] = 0x00;  
        t_ns[5] = 0x01;  
        t_ns[6] = 0x00;  
        t_ns[7] = 0x00;  
        t_ns[8] = 0x00;  
        t_ns[9] = 0x00;  
        t_ns[10] = 0x00;  
        t_ns[11] = 0x00;  
        t_ns[12] = 0x20;  
        t_ns[13] = 0x43;  
        t_ns[14] = 0x4B;  
  
        for(int i = 15; i < 45; i++){  
            t_ns[i] = 0x41;  
        }  
        t_ns[45] = 0x00;  
        t_ns[46] = 0x00;  
        t_ns[47] = 0x21;  
        t_ns[48] = 0x00;  
        t_ns[49] = 0x01;  
        return t_ns;  
    }  
    
/**
 * 將byte數組轉換成常用的mac格式展示
 * @param brevdata mac碼的byte數組形式數據
 * @return 格式化brevdata變爲mac格式
 * @throws Exception
 */
public final String GetMacAddr(byte[] brevdata) throws Exception {  
        // 獲取計算機名  
        int i = brevdata[56] * 18 + 56;  
        String sAddr="";  
        StringBuffer sb = new StringBuffer(17);  
        // 先從第56字節位置，讀出Number Of Names（NetBIOS名字的個數，其中每個NetBIOS Names Info部分佔18個字節）  
        // 然後可計算出“Unit ID”字段的位置＝56＋Number Of Names×18，最後從該位置起連續讀取6個字節，就是目的主機的MAC地址。  
        for(int j = 1; j < 7;j++)  
        {  
            sAddr = Integer.toHexString(0xFF & brevdata[i+j]);  
            if(sAddr.length() < 2)  
            {  
                sb.append(0);  
            }  
            sb.append(sAddr.toUpperCase());  
            if(j < 6) sb.append(':');  
        }  
        return sb.toString();  
    }  
  /**
   * 關閉udp請求
   * @throws Exception
   */
    public final void close() throws Exception {  
        ds.close();  
    }  
  /**
   *  流程主方法
   * @return mac值
   * @throws Exception
   */
    public final String GetRemoteMacAddr() throws Exception {  
        byte[] bqcmd = GetQueryCmd();//或得一個初始化的數組  
        System.out.println("dqcmd"+Arrays.toString(bqcmd));
        send(bqcmd); //將初始化的數組放入發送包裏面
        DatagramPacket dp = receive();//得到緩衝數據組
        System.out.println(Arrays.toString(dp.getData()));
        String smac = GetMacAddr(dp.getData()); //將緩存數據進行mac格式化
        close();  
  
        return smac;  
    }  
    
    /**
     * 獲取用戶端的IP地址
     * @param request
     * @return
     */
    public static String getIp(HttpServletRequest request) {
    	String ip = request.getHeader("X-Forwarded-For");
    	if(ip!=null) {
    		if(!ip.isEmpty()&&!"unKnown".equalsIgnoreCase(ip)) {
    			int index = ip.indexOf(",");
    			if(index!=-1) {
    				 return ip.substring(0, index);
    			}else {
    				return ip;
    			}
    		}
    	}
    	ip = request.getHeader("X-Real-IP");
    	if(ip!=null){
    		if(!ip.isEmpty()&&!"unKnown".equalsIgnoreCase(ip)) {
    			return ip;
    		}
    	}
    	 ip = request.getHeader("Proxy-Client-IP");
    	    if (ip != null) {
    	        if (!ip.isEmpty() && !"unKnown".equalsIgnoreCase(ip)) {
    	            return ip;
    	        }
    	    }
    	    ip = request.getHeader("WL-Proxy-Client-IP");
    	    if (ip != null) {
    	        if (!ip.isEmpty() && !"unKnown".equalsIgnoreCase(ip)) {
    	            return ip;
    	        }
    	    }
    	  ip =  request.getRemoteAddr();
    	  return ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;
    }
      
    public static void main(String args[]) throws Exception{  
        UdpGetClientMacAddr umac1=new UdpGetClientMacAddr("192.168.67.235");  
       // UdpGetClientMacAddr umac2=new UdpGetClientMacAddr("192.168.67.43");  
        System.out.println("umac1:"+umac1.GetRemoteMacAddr());  
        //System.out.println("umac2:"+umac2.GetRemoteMacAddr());  
    }  
}