Android 判断SIM卡属于哪个移动运营商

Android这样获取本机网络提供商呢？请看下面代码：

 public String getProvidersName()    {      String str = "N/A";      try      {        this.IMSI = this.telephonyManager.getSubscriberId();        System.out.println(this.IMSI);        if (this.IMSI.startsWith("46000"))         str = "中国移动";  break;        if (this.IMSI.startsWith("46002"))         str = "中国移动"; break ;        if (this.IMSI.startsWith("46001"))          str = "中国联通";        else if (this.IMSI.startsWith("46003"))          str = "中国电信";      }      catch (Exception localException)      {        localException.printStackTrace();      }           return str;    }

    this.telephonyManager = ((TelephonyManager)paramContext.getSystemService("phone"));