1
我想在插入USB时启用该按钮,并在USB被移除时将其禁用。每次插入或拔出USB时,如何使用ajax更改按钮?如何在每次servlet发生更改时执行ajax函数?
阿贾克斯
function loadXML(){
var xmlhttp;
if (window.XMLHttpRequest)
{
xmlhttp = new XMLHttpRequest();
}
else
{
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
alert (xmlhttp.responseText);
if(xmlhttp.responseText == "true") {
document.getElementById('scan').disabled=false;
}
else {
document.getElementById('scan').disabled=true;
}
}
}
xmlhttp.open("GET", "ScanJobServlet", true);
xmlhttp.send();
}
Servlet-我怎样才能重新向JSP每次响应事件监听器被触发,并再次执行AJAX功能?
public static boolean status = false;
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(req, resp);
PrintWriter out = resp.getWriter();
RemovableStorageEventListener listener = new RemovableStorageEventListener()
{
public void inserted(Storage storage) {
status = true;
}
public void removed(Storage storage) {
status = false;
}
};
BundleContext bc = AppManager.getInstance().getBundleContext();
StorageManager sm = StorageManager.getInstance(KSFUtility.getInstance().getApplicationContext(bc));
sm.addListener(listener);
if (status==true)
{
out.print("true");
}
else
{
resp.reset();
}
}