//获取手机的唯一标识
 public String getPhoneSign(){
   StringBuilder deviceId = new StringBuilder();
   // 渠道标志
   deviceId.append("a");
   try {
    //IMEI（imei）
    TelephonyManager tm = (TelephonyManager) this.getSystemService(Context.TELEPHONY_SERVICE);
    String imei = tm.getDeviceId();
    if(!TextUtils.isEmpty(imei)){
     deviceId.append("imei");
     deviceId.append(imei);
     return deviceId.toString();
    }
    //序列号（sn）
    String sn = tm.getSimSerialNumber();
    if(!TextUtils.isEmpty(sn)){
     deviceId.append("sn");
     deviceId.append(sn);
     return deviceId.toString();
    }
    //如果上面都没有， 则生成一个id：随机码
    String uuid = getUUID();
    if(!TextUtils.isEmpty(uuid)){
     deviceId.append("id");
     deviceId.append(uuid);
     return deviceId.toString();
    }
   } catch (Exception e) {
    e.printStackTrace();
    deviceId.append("id").append(getUUID());
   }
   return deviceId.toString();
  }
/**
  * 得到全局唯一UUID
  */
 private String uuid;
 public String getUUID(){
  SharedPreferences mShare = getSharedPreferences("uuid",MODE_PRIVATE);
  if(mShare != null){
   uuid = mShare.getString("uuid", "");
  }
  if(TextUtils.isEmpty(uuid)){
   uuid = UUID.randomUUID().toString();
   mShare.edit().putString("uuid",uuid).commit();
  }
  return uuid;
 }