webview 缓存问题

因项目需要，需要在app中获取客户的内网IP地址，使用js实现，经测试发现，在hbulider上的app获取ip地址时，如果切换无线网络，再获取不生效，还是上次连接的无线网ip，必须关闭软件清除手机缓存后才生效，同理，在手机谷歌浏览器下测试就没有问题，现在贴出代码，给大家试一下，不知道是不是bug问题，还是我没有找到正确的方法：

<script>  
    getIPs(function(ip) {  

        if (ip.match(/^(192\.168\.|169\.254\.|10\.|172\.(1[6-9]|2\d|3[01]))/)) {  
            alert(ip);  
        }  
    });  

    function getIPs(callback) {  
        var ip_dups = {};  

        //compatibility for firefox and chrome     
        var RTCPeerConnection = window.RTCPeerConnection  
                || window.mozRTCPeerConnection  
                || window.webkitRTCPeerConnection;  
        var mediaConstraints = {  
            optional: [{RtpDataChannels: true}]  
        };  

        //firefox already has a default stun server in about:config     
        //    media.peerconnection.default_iceservers =     

        var servers = undefined;  

        //add same stun server for chrome     
        if (window.webkitRTCPeerConnection)  
            servers = {iceServers: [{urls: "stun:stun.services.mozilla.com"}]};  

        //construct a new RTCPeerConnection     
        var pc = new RTCPeerConnection(servers, mediaConstraints);  

        //listen for candidate events     
        pc.onicecandidate = function(ice) {  

            //skip non-candidate events     
            if (ice.candidate) {  

                //match just the IP address     
                var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/;  
                var ip_addr = ip_regex.exec(ice.candidate.candidate)[1];  

                //remove duplicates     
                if (ip_dups[ip_addr] === undefined)  
                    callback(ip_addr);  

                ip_dups[ip_addr] = true;  
            }  
        };  

        //create a bogus data channel     
        pc.createDataChannel("");  

        //create an offer sdp     
        pc.createOffer(function(result) {  

            //trigger the stun server request     
            pc.setLocalDescription(result, function() {  
            });  

        }, function() {  
        });  
    }  

</script>