android 客户端发送http访问服务器端，网络检测

public void CheckNetworkState(){
boolean flag = false;
ConnectivityManager manager = (ConnectivityManager)getSystemService(
Context.CONNECTIVITY_SERVICE);
State mobile = manager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();
State wifi = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();
//如果3G、wifi、2G等网络状态是连接的，则退出，否则显示提示信息进入网络设置界面
if(mobile == State.CONNECTED||mobile==State.CONNECTING)
return;
if(wifi == State.CONNECTED||wifi==State.CONNECTING)
return;
showTips();
}

private void showTips(){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(android.R.drawable.ic_dialog_alert);
builder.setTitle("没有可用网络");
builder.setMessage("当前网络不可用，是否设置网络？");
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// 如果没有网络连接，则进入网络设置界面
startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
LoginActivity.this.finish();
}
});
builder.create();
builder.show();
}