一个有用的类，集合了建立、连接热点；获取本机ip和连接此热点的手机的ip地址等方法

package dislab.gossipdog.wifi.adhoc;

import java.io.BufferedReader;
import java.io.FileReader;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.DhcpInfo;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.text.format.Formatter;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class AdHocActivity extends Activity {
	private final String TAG = "WifiSoftAP";
    public static final String WIFI_AP_STATE_CHANGED_ACTION =
        "android.net.wifi.WIFI_AP_STATE_CHANGED";

    public static final int WIFI_AP_STATE_DISABLING = 0;
    public static final int WIFI_AP_STATE_DISABLED = 1;
    public static final int WIFI_AP_STATE_ENABLING = 2;
    public static final int WIFI_AP_STATE_ENABLED = 3;
    public static final int WIFI_AP_STATE_FAILED = 4;  
	
    
    TextView result;
	WifiManager wifiManager;
	WifiReceiver receiverWifi;
	List<ScanResult> wifiList;
	//����l���б�  
    private List<WifiConfiguration> wifiConfiguration;
	StringBuilder resultList = new StringBuilder();

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		//setTitle("");
		result = (TextView) findViewById(R.id.result);
		wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
		
		
		Button btnOpenAP = (Button)this.findViewById(R.id.btnOpenAP);
		btnOpenAP.setOnClickListener(new OnClickListener() {            
			public void onClick(View v) {
				if (!isApEnabled()){
					setWifiApEnabled(true);
				}
        	}
        });
		
		
		Button btnCloseAP = (Button)this.findViewById(R.id.btnCloseAP);
		btnCloseAP.setOnClickListener(new OnClickListener() {            
			public void onClick(View v) {
				if (isApEnabled()){
					setWifiApEnabled(false);
				}
        	}
        });
		
		
		Button btnScan = (Button)this.findViewById(R.id.btnScan);
		btnScan.setOnClickListener(new OnClickListener() {            
			public void onClick(View v) {
				if (!wifiManager.isWifiEnabled()) {
					wifiManager.setWifiEnabled(true);
				}
				StartScan();
        	}
        });
		
		
		Button btnConnectAP = (Button)this.findViewById(R.id.btnConnectAP);
		btnConnectAP.setOnClickListener(new OnClickListener() {            
			public void onClick(View v) {
				connectAP();
        	}
        });
		
		
		Button btnGetConnectedIP = (Button)this.findViewById(R.id.btnGetConnectedIP);
		btnGetConnectedIP.setOnClickListener(new OnClickListener() {            
			public void onClick(View v) {
				ArrayList<String> connectedIP = getConnectedIP();
				resultList = new StringBuilder();
				for(String ip : connectedIP){
					resultList.append(ip);
					resultList.append("\n");
				}
				result.setText(resultList);				
				
        	}
        });
       
		
		findViewById(R.id.btnGetOwmId).setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Log.d("ZSM", getLocalIpAddress());
				
				WifiInfo wifiinfo = wifiManager.getConnectionInfo();
				  Log.v("getBSSID", wifiinfo.getBSSID() + "");
				  Log.v("getHiddenSSID", wifiinfo.getBSSID() + "");
				  Log.v("getIpAddress", Formatter.formatIpAddress(wifiinfo.getIpAddress()) + "");
				  Log.v("getLinkSpeed", Formatter.formatIpAddress(wifiinfo.getLinkSpeed()) + "");
				  Log.v("getMacAddress", wifiinfo.getMacAddress() + "");
				  Log.v("getNetworkId", Formatter.formatIpAddress(wifiinfo.getNetworkId()) + "");
				  Log.v("getRssi", wifiinfo.getRssi() + "");
				  Log.v("getSSID", wifiinfo.getSSID() + "");

				DhcpInfo dhcpinfo = wifiManager.getDhcpInfo();
				  Log.v("ipaddr", Formatter.formatIpAddress(dhcpinfo.ipAddress) + "");
				  Log.v("gatewau", Formatter.formatIpAddress(dhcpinfo.gateway) + "");
				  Log.v("netmask", Formatter.formatIpAddress(dhcpinfo.netmask) + "");
				  Log.v("dns1", Formatter.formatIpAddress(dhcpinfo.dns1) + "");
				  Log.v("dns1", Formatter.formatIpAddress(dhcpinfo.dns2) + "");
				  Log.v("serverAddress", Formatter.formatIpAddress(dhcpinfo.serverAddress) + "");
				  Log.d("ZSM", Formatter.formatIpAddress(dhcpinfo.serverAddress));
				  Log.d("ZSM","ipaddr  "+ Formatter.formatIpAddress(dhcpinfo.ipAddress));
				  
				  
			}
		});
		

	}
	
	//此方法暂不可用
    public String getLocalIpAddress() {  
        try {  
            for (Enumeration<NetworkInterface> en = NetworkInterface  
                    .getNetworkInterfaces(); en.hasMoreElements();) {  
                NetworkInterface intf = en.nextElement();  
                for (Enumeration<InetAddress> enumIpAddr = intf  
                        .getInetAddresses(); enumIpAddr.hasMoreElements();) {  
                    InetAddress inetAddress = enumIpAddr.nextElement();  
                    if (!inetAddress.isLoopbackAddress()) {  
                        return inetAddress.getHostAddress().toString();  
                    }  
                }  
            }  
        } catch (SocketException ex) {  
            Log.e("WifiPreference IpAddress", ex.toString());  
        }  
        return null;  
    }  
      
    public String getLocalMacAddress() {  
        WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);  
        WifiInfo info = wifi.getConnectionInfo();  
        return info.getMacAddress();  
    }  

	protected void onPause() {
		if (receiverWifi != null)
			unregisterReceiver(receiverWifi);
		
		super.onPause();
	}

	protected void onResume() {
		if (receiverWifi != null)
			registerReceiver(receiverWifi, new IntentFilter(
					WifiManager.SCAN_RESULTS_***AILABLE_ACTION));

		super.onResume();
	}

	
	public void StartScan() {
		//��wifi
		wifiManager.setWifiEnabled(true);

		receiverWifi = new WifiReceiver();
		registerReceiver(receiverWifi, new IntentFilter(
				WifiManager.SCAN_RESULTS_***AILABLE_ACTION));
		wifiManager.startScan();
		result.setText("\nScaning...\n");  
	}
	
	
	public boolean setWifiApEnabled(boolean enabled) {
		if (enabled) { // disable WiFi in any case
			wifiManager.setWifiEnabled(false);
		}
    	
		try {
			WifiConfiguration apConfig = new WifiConfiguration();
			apConfig.SSID = "GossipDog";
			apConfig.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
			apConfig.preSharedKey = "abcdefgh";
			
			Method method = wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, Boolean.TYPE);
			return (Boolean) method.invoke(wifiManager, apConfig, enabled);
		} catch (Exception e) {
			Log.e(TAG, "Cannot set WiFi AP state", e);
			return false;
		}
	}

	
	
	public int getWifiApState() {
		try {
			Method method = wifiManager.getClass().getMethod("getWifiApState");
			return (Integer) method.invoke(wifiManager);
		} catch (Exception e) {
			Log.e(TAG, "Cannot get WiFi AP state", e);
			return WIFI_AP_STATE_FAILED;
		}
	}
	
	public boolean isApEnabled() {
        int state = getWifiApState();
        return WIFI_AP_STATE_ENABLING == state || WIFI_AP_STATE_ENABLED == state;
	}

    
    //l��GossipDog  
    public void connectAP() { 
    	WifiConfiguration gossipDog = new WifiConfiguration();
        for (WifiConfiguration ap : wifiConfiguration) { 
        	if (ap.SSID == "GossipDog") {
        		gossipDog = ap;
        	}
        } 
        
        if (gossipDog != null) {
        	gossipDog.preSharedKey = "abcdefgh";
        	gossipDog.networkId = wifiManager.addNetwork(gossipDog);
        	wifiManager.enableNetwork(gossipDog.networkId, true);
        	result.setText("l��AP�ɹ�");
        } 
        
    }
    
    //获取所有连接到本wifi热点的手机IP地址
    private ArrayList<String> getConnectedIP() {
        ArrayList<String> connectedIP = new ArrayList<String>();
        try {
        	BufferedReader br = new BufferedReader(new FileReader("/proc/net/arp"));
            String line;
            while ((line = br.readLine()) != null) {
            	Log.d("meng", line);
                String[] splitted = line.split(" +");
                if (splitted != null && splitted.length >= 4) {
                    String ip = splitted[0];
                    connectedIP.add(ip);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return connectedIP;
    }
	 
	class WifiReceiver extends BroadcastReceiver {

		public void onReceive(Context c, Intent intent) {
			resultList = new StringBuilder();
			wifiList = wifiManager.getScanResults();
			for (int i = 0; i < wifiList.size(); i++) {
				resultList.append(new Integer(i + 1).toString() + ".");
				resultList.append((wifiList.get(i)).toString());
				resultList.append("\n\n");
			}
			result.setText(resultList);
			
			//�õ����úõ�����l��  
		    wifiConfiguration = wifiManager.getConfiguredNetworks();
		}
	}
}