public class JajaMenu extends Activity {    public static JajaMenu instance;        @Override    public void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        super.init();        instance=this;    }      //获取实例      public static JajaMenu getInstance(){          return instance;      }}

public static final int NETTYPE_WIFI = 0x01;public static final int NETTYPE_CMWAP = 0x02;public static final int NETTYPE_CMNET = 0x03;

/**     * 检测网络是否可用     * @return     */    public boolean isNetworkConnected(){        ConnectivityManager cm=(ConnectivityManager)JajaMenu.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);        NetworkInfo networkInfo=cm.getActiveNetworkInfo();        return networkInfo !=null && networkInfo.isConnectedOrConnecting();    }        /**     * 获取网络类型     * @return 0：没有网络   1：WIFI网络   2：WAP网络    3：NET网络     * */    public int getNetworkType(){        int netType=0;        ConnectivityManager cm=(ConnectivityManager)JajaMenu.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);        NetworkInfo networkInfo=cm.getActiveNetworkInfo();        if(networkInfo == null){            return netType;        }        int nType=networkInfo.getType();        if(nType ==ConnectivityManager.TYPE_MOBILE){            String extraInfo=networkInfo.getExtraInfo();            if(!extraInfo.isEmpty()){                String strInfo=extraInfo.toLowerCase();                if(strInfo.equals("cmnet")){                    netType=NETTYPE_CMNET;                }                else{                    netType=NETTYPE_CMWAP;                }            }        }        else if(nType ==ConnectivityManager.TYPE_WIFI){            netType=NETTYPE_WIFI;        }        return netType;    }