WebView  wv_clock = findViewById(R.id.wv_clock);
WebSettings webSettings = wv_clock.getSettings();
wv_clock.getSettings().setJavaScriptEnabled(true);
// 设置可以访问文件
webSettings.setAllowFileAccess(true);
webSettings.setAllowFileAccessFromFileURLs(true);
webSettings.setAllowContentAccess(true);
webSettings.setDomStorageEnabled(true);
wv_clock.getSettings().setAllowFileAccessFromFileURLs(true);
//js与android调用
wv_clock.loadUrl("file:///android_asset/clock/clock_local.html");