Android原生和H5混合开发，要求用户退出登录后清空H5所有的缓存；
1、清空Cookie
CookieSyncManager.createInstance(context.getApplicationContext());
CookieManager cookieManager = CookieManager.getInstance();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
cookieManager.removeSessionCookies(null);
cookieManager.removeAllCookie();
cookieManager.flush();
} else {
cookieManager.removeSessionCookies(null);
cookieManager.removeAllCookie();
CookieSyncManager.getInstance().sync();
}
2、清空Localstorage；
清空H5保存在本地的所有内容；
WebStorage.getInstance().deleteAllData(); //清空WebView的localStorage
/questions/14653916/deleting-localstorage-but-still-persists
