WebView預加載，解析網頁

//url確保是以http開頭

 private void init(String link) {
        setWebViewClient(new WebViewClient() {
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                mHasPageStarted = true;
                mPageUrl = url;
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
                mHasPageFinished = true;
                mPageUrl = url;
            }

            @Override
            public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
                super.doUpdateVisitedHistory(view, url, isReload);
            }

            @Override
            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
                super.onReceivedError(view, request, error);
            }

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (!url.startsWith("http")) {
                    return true;
                }

                for (int i = 0; i < mOnWebViewListeners.size(); i++) {
                    if (mOnWebViewListeners.get(i).shouldOverrideUrlLoading(CrawlWebView.this, url)) {
                        return true;
                    }
                }

                return super.shouldOverrideUrlLoading(view, url);
            }
        });

        setWebChromeClient(new WebChromeClient() {

            @Override
            public void onReceivedTitle(WebView view, String title) {
                super.onReceivedTitle(view, title);
                mHasLoadedWebViewTitle = true;
                mWebViewTitle = title;
                notifyOnReceivedTitle();
            }

            @Override
            public void onProgressChanged(WebView view, int newProgress) {
            }

            @Override
            public void onReceivedIcon(WebView view, Bitmap icon) {
                super.onReceivedIcon(view, icon);
                mHasLoadedWebViewIcon = true;
                mWebViewIcon = icon;
            }

            @Override
            public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                result.cancel();
                return true;
            }
        });
        getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        getSettings().setJavaScriptEnabled(true);
        getSettings().setDomStorageEnabled(true);
    }