代码修改mac地址（需要root）

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.os.Handler;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

/**
 * 获取root权限，读取并修改系统文件
 *
 */
public class RootTestActivity extends Activity {
    private final static int CHANGE_OK = 1;
    private final static int WIFI_OK = 2;
    
    private ListView contentList;
    private FileAdapter adapter;
    private ArrayList<String> datas = new ArrayList<String>();
    private TextView resultTxt;
    private WifiManager wifi;
    private WifiReceiver wifiReceiver = null;
    
    private Button send;
    private Button change;
    
    /**
     * 是否是第一次执行
     */
    private boolean isFirst = true;
    
    private Handler handler = new Handler(){
        public void handleMessage(android.os.Message msg) {
            switch (msg.what) {
            case CHANGE_OK:
                // 改完后重启wifi
                changeWifiState();
                break;
            case WIFI_OK:
                // 重启wifi结束
                resultTxt.setText("修改完成，mac为： " + getLocalMacAddress());
                changeBtnState();
                break;

            default:
                break;
            }
        };
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_su);
        
        wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE); 
        wifiReceiver = new WifiReceiver();
        IntentFilter filter=new IntentFilter();  
        filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);  
        registerReceiver(wifiReceiver, filter);
        
        send = (Button) findViewById(R.id.send);
        change = (Button) findViewById(R.id.change);
        resultTxt = (TextView) findViewById(R.id.content_edit);
        contentList = (ListView) findViewById(R.id.content);
        searchFile("");
        adapter = new FileAdapter(this, datas);
        contentList.setAdapter(adapter);
        contentList.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                String filePath = datas.get(position);
                runRootCommand("chmod  755 " + filePath);
                searchFileByPath(filePath);
                adapter.notifyDataSetChanged();
                contentList.setSelection(0);
            }
        });
        
        resultTxt.setText(getIMEI());
    }

    public String searchFile(String keyword) {
        datas.clear();
        String result = "";
        File parentFile = new File("/");
        File[] files = parentFile.listFiles();
        for (File file : files) {
            if (file.getName().indexOf(keyword) >= 0) {
                result += file.getPath() + "\n";
                datas.add(file.getPath());
            }
        }
        if (result.equals("")) {
            result = "找不到文件!!";
        }
        return result;
    }

    public String searchFileByPath(String path) {
        String result = "";
        File parentFile = new File(path + "/");

        if (parentFile.isFile()) {
            runRootCommand("chmod  777 " + path + "/");
            
            try {
                // 重写文件
//                reWriteFile(path + "/");
                writeSDFile(path, parentFile);
                
//                result = readSDFile(parentFile);
//                runRootCommand("chmod  660 " + path + "/");
                isFirst = false;
                changeBtnState();
                handler.sendEmptyMessageDelayed(CHANGE_OK, 500);
                resultTxt.setText("请稍等...");
            } catch (IOException e) {
                e.printStackTrace();
                resultTxt.setText("修改失败");
            }
            
            return result;
        }

        File[] files = parentFile.listFiles();
        if (files != null && files.length > 0) {
            datas.clear();
            for (File file : files) {
                datas.add(file.getPath());
            }
        } else {
            Toast.makeText(RootTestActivity.this, "找不到文件!!",
                    Toast.LENGTH_SHORT).show();
        }
        return result;
    }

    public static boolean runRootCommand(String command) {
        Process process = null;
        DataOutputStream os = null;
        try {
            process = Runtime.getRuntime().exec("su");
            os = new DataOutputStream(process.getOutputStream());
            os.writeBytes(command + "\n");
            os.writeBytes("exit\n");
            os.flush();
            process.waitFor();
        } catch (Exception e) {
            Log.d("*** DEBUG ***", "Unexpected error - Here is what I know: "
                    + e.getMessage());
            return false;
        } finally {
            try {
                if (os != null) {
                    os.close();
                }
                process.destroy();
            } catch (Exception e) {
                // nothing
            }
        }
        return true;
    }

    public void onClick(View view) {
        switch (view.getId()) {
        case R.id.send:
            String filePath = datas.get(0);
            int index = filePath.lastIndexOf("/");
            if (index > 1) {
                filePath = filePath.substring(0, index);
                index = filePath.lastIndexOf("/");
                // if (index > 1) {
                filePath = filePath.substring(0, index);
                runRootCommand("chmod  755 " + filePath);
                searchFileByPath(filePath);
                adapter.notifyDataSetChanged();
                // } else {
                // Toast.makeText(RootTestActivity.this, "已经是最上层",
                // Toast.LENGTH_SHORT).show();
                // }
            } else {
                Toast.makeText(RootTestActivity.this, "已经是最上层",
                        Toast.LENGTH_SHORT).show();
            }
            break;
        case R.id.change:
            // 一键修改mac
            changeMac();
            break;

        default:
            break;
        }
    }

    // 读文件
    public String readSDFile(File file) throws IOException {
        String res = "";
//        File file = new File(fileName);

        FileInputStream fis = new FileInputStream(file);

        int length = fis.available();

        byte[] buffer = new byte[length];
        fis.read(buffer);

//        res = EncodingUtils.getString(buffer, "UTF-8");
        res = bytesToHexString(buffer);

        fis.close();
        return res;
    }
    
    public static String bytesToHexString(byte[] bytes) {
        String result = "";
        for (int i = 0; i < bytes.length; i++) {
            if (i > 3 && i < 10) {
                String hexString = Integer.toHexString(bytes[i] & 0xFF);
                if (hexString.length() == 1) {
                    hexString = ‘0‘ + hexString;
                }
                result += hexString.toUpperCase();
            }
            
        }
        return result;
    }

    // 写文件
    public void writeSDFile(String fileName, String write_str)
            throws IOException {

        File file = new File(fileName);

        FileOutputStream fos = new FileOutputStream(file);

        byte[] bytes = write_str.getBytes();

        fos.write(bytes);

        fos.close();
    }
    
    // 写文件
    public void writeSDFile(String fileName,  File fileParent) throws IOException {
        // 先读取文件
        FileInputStream fis = new FileInputStream(fileParent);

        int length = fis.available();

        byte[] bytes = new byte[length];
        fis.read(bytes);
        fis.close();
        // 修改其中的内容
        for (int i = 0; i < bytes.length; i++) {
            if (i > 3 && i < 10) {
                bytes[i] = (byte) (Math.random() * 128);
            }
            
        }
        // 删除源文件
        runRootCommand("chmod  777 " + fileName + "/");
        fileParent.delete();
        // 写入文件
        File file = new File(fileName);

        FileOutputStream fos = new FileOutputStream(file);

        fos.write(bytes);

        fos.close();
    }
    
    /**
     * 修改固定位置文件内容
     * @throws IOException
     */
    public void reWriteFile(String file) throws IOException {
        // 以读写方式打开文件
        RandomAccessFile raf = new RandomAccessFile(file, "rw");
        byte[] buff = new byte[1024 * 1024];

        // 整个数组的偏移，也可以理解为字符数
        int pos = 0;
        // 行数，以‘\n‘为行标记
        int lineNum = 1;
        // 第五行的开始字节数
        int startPos = 3;
        // 第五行的结束字节数
        int endPos = 10;
        
//        int read = -1;
//        do {
//            read = raf.read(buff);
//            for (int i = 0; i < read; i++) {
//                pos++;
//                // 行尾
//                if (buff[i] == ‘\n‘) {
//                    lineNum++;
//                    if (lineNum == 5) {
//                        startPos = pos;
//                    }
//                    if (lineNum == 6) {
//                        endPos = pos - 2;
//                        break;
//                    }
//                }
//            }
//        } while (lineNum < 6 && read != -1);

        if (endPos > startPos) {
            // 指针偏移到第五行的第一个字节
            raf.seek(startPos);
            for (int i = 0, len = endPos - startPos; i < len; i++) {
                // 替换第五行的所有字节
                raf.write(‘X‘);
            }
        }
        raf.close();
    }
    
    /**
     * 获取mac地址
     * @return
     */
    public String getLocalMacAddress() { 
        WifiInfo info = wifi.getConnectionInfo(); 
        return info.getMacAddress(); 
    } 
    
    /**
     * @return        获取串号
     */
    public String getIMEI() {
        TelephonyManager tm = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE); 
//        String DEVICE_ID = android.os.SystemProperties.get("gsm.imei");//tm.getDeviceId(); 
        String DEVICE_ID = tm.getDeviceId(); 
        String te1  = tm.getLine1Number();
        return DEVICE_ID + "\n" + te1;
    }
    
    /**
     * 改变wifi状态
     */
    public void changeWifiState() {
        if (wifi.isWifiEnabled()) {  
            wifi.setWifiEnabled(false);  
            } else {  
                wifi.setWifiEnabled(true);  
            }
    }

    
    class WifiReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            if(intent.getAction().equals(WifiManager.WIFI_STATE_CHANGED_ACTION)){//wifi打开与否
                int wifistate = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_DISABLED);
                
                if(wifistate == WifiManager.WIFI_STATE_DISABLED){
                    // 如果关闭则打开
                    Toast.makeText(RootTestActivity.this, "系统关闭wifi",
                            Toast.LENGTH_SHORT).show();
                    changeWifiState();
                }
                else if(wifistate == WifiManager.WIFI_STATE_ENABLED && !isFirst){
                    isFirst = false;
                    Toast.makeText(RootTestActivity.this, "系统开启wifi",
                            Toast.LENGTH_SHORT).show();
                    handler.sendEmptyMessage(WIFI_OK);
                }
            }
        }
        
    }
    
    /**
     * 一键修改mac
     */
    public void changeMac() {
        searchFileByPath("/data");
        searchFileByPath("/data/nvram");
        searchFileByPath("/data/nvram/APCFG");
        searchFileByPath("/data/nvram/APCFG/APRDEB");
        searchFileByPath("/data/nvram/APCFG/APRDEB/WIFI");
    }
    
    /**
     * 改变按钮状态
     */
    private void changeBtnState() {
        boolean state = send.isEnabled();
        send.setEnabled(!state);
        change.setEnabled(!state);
    }
    
    @Override
    protected void onDestroy() {
        if (null != wifiReceiver) {
            unregisterReceiver(wifiReceiver);
        }
        super.onDestroy();
    }
}