Android原生和H5混合開發，要求使用者退出登入後清空H5所有的快取；

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儲存在本地的所有內容；

WebStorage.getInstance().deleteAllData(); //清空WebView的localStorage

https://stackoverflow.com/questions/14653916/deleting-localstorage-but-still-persists