PhoneGap 中网络判断

<script language="javascript" type="text/javascript">
  function checkConnection() {
    var networkState = navigator.network.connection.type;
    var states = {};
    states[Connection.UNKNOWN]  = 'Unknown connection';
    states[Connection.ETHERNET] = 'Ethernet connection';
    states[Connection.WIFI]     = 'WiFi connection';
    states[Connection.CELL_2G]  = 'Cell 2G connection';
    states[Connection.CELL_3G]  = 'Cell 3G connection';
    states[Connection.CELL_4G]  = 'Cell 4G connection';
    states[Connection.NONE]     = 'No network connection';
    alert('Connection type: ' + states[networkState]);
  }
</script>