java - can applet load jar dynamically? -

i load jar when specific button on applet clicked.

i want avoid user prompted security warning against jar when applet loaded, warning should appeared when button clicked.

i using webstart.

the code , errors follows.

    policy.setpolicy(new policy() {         public permissioncollection getpermissions(codesource codesource) {             permissions perms = new permissions();             perms.add(new allpermission());             return (perms);         }          public void refresh() {         }     });      system.setsecuritymanager(null);      classloader wcl = mainapplet.class.getclassloader();      url[] urls = new url[1];     string protocol="http";     string host="localhost";     int port = 8080;     string file = "mb/download/ubikey-1.0.2.5.jar";     //      string url = urlencoder("http://localhost:11090/multitoolkitdemo/download/ubikey-1.0.2.5.jar");     urls[0] = new url(protocol, host, port, file);       try {         ds = (downloadservice) servicemanager                 .lookup("javax.jnlp.downloadservice");          // determine if particular resource cached         url url = new url(                 "http://localhost:8080/mb/download/ubikey-1.0.2.5.jar");         boolean cached = ds.isresourcecached(url, "1.0");         // remove resource cache         if (cached) {             ds.removeresource(url, "1.0");         }         // reload resource cache         downloadservicelistener dsl = ds.getdefaultprogresswindow();         ds.loadresource(url, "1.0", dsl);     } catch (exception e) {         e.printstacktrace();     }     urlclassloader cl = new urlclassloader(urls, wcl);     try {         cl.loadclass("kr.co.jubikey.jubikeymanager");     } catch (classnotfoundexception e1) {         // todo auto-generated catch block         e1.printstacktrace();     } 

error follows.

cache: memorycache replacing http://localhost:8080/mb/download/ubikey-1.0.2.5.jar (refcnt=2). was: url: http://localhost:8080/mb/download/ubikey-1.0.2.5.jar | /users/rnd/library/application support/oracle/java/deployment/cache/6.0/14/2e04ea0e-6e999798-1.0-.idx now: url: http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz | /users/rnd/library/application support/oracle/java/deployment/cache/6.0/32/5c664da0-4e2b1d6e.idx cache: reading signers 3607 http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz | /users/rnd/library/application support/oracle/java/deployment/cache/6.0/32/5c664da0-4e2b1d6e.idx cache: done readsigners(http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz) cache:  read manifest http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz: read=130 full=7460 basic: plugin2classloader.istrustedbypolicy called  basic: plugin2classloader.istrustedbypolicy returns false  security: resource name "kr/co/jubikey/jubikeymanager.class" in http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz : java.lang.securityexception: attempted open sandboxed jar http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz trusted-library exception in thread "awt-eventqueue-2" java.lang.securityexception: attempted open sandboxed jar http://localhost:8080/mb/download/ubikey-1.0.2.5.jar.pack.gz trusted-library     @ com.sun.deploy.security.cpcallbackhandler$parentelement.checkresource(unknown source)     @ com.sun.deploy.security.deployurlclasspath$jarloader.checkresource(unknown source)     @ com.sun.deploy.security.deployurlclasspath$jarloader.getresource(unknown source)     @ com.sun.deploy.security.deployurlclasspath.getresource(unknown source)     @ sun.plugin2.applet.plugin2classloader$2.run(unknown source)     @ java.security.accesscontroller.doprivileged(native method)     @ sun.plugin2.applet.plugin2classloader.findclasshelper(unknown source)     @ sun.plugin2.applet.jnlp2classloader.findclass(unknown source)     @ sun.plugin2.applet.plugin2classloader.loadclass0(unknown source)     @ sun.plugin2.applet.plugin2classloader.loadclass(unknown source)     @ sun.plugin2.applet.plugin2classloader.loadclass(unknown source)     @ java.lang.classloader.loadclass(classloader.java:411)     @ java.lang.classloader.loadclass(classloader.java:357)     @ com.ktnet.pki.multibrowser.util.jnlputil.loadjar(jnlputil.java:69)     @ com.ktnet.pki.multibrowser.dialog.selectcertificatedlg$10.run(selectcertificatedlg.java:1945)     @ java.awt.event.invocationevent.dispatch(invocationevent.java:251)     @ java.awt.eventqueue.dispatcheventimpl(eventqueue.java:733)     @ java.awt.eventqueue.access$200(eventqueue.java:103)     @ java.awt.eventqueue$3.run(eventqueue.java:694)     @ java.awt.eventqueue$3.run(eventqueue.java:692)     @ java.security.accesscontroller.doprivileged(native method)     @ java.security.protectiondomain$1.dointersectionprivilege(protectiondomain.java:76)     @ java.awt.eventqueue.dispatchevent(eventqueue.java:703)     @ java.awt.eventdispatchthread.pumponeeventforfilters(eventdispatchthread.java:242)     @ java.awt.eventdispatchthread.pumpeventsforfilter(eventdispatchthread.java:161)     @ java.awt.eventdispatchthread.pumpeventsforhierarchy(eventdispatchthread.java:150)     @ java.awt.eventdispatchthread.pumpevents(eventdispatchthread.java:146)     @ java.awt.eventdispatchthread.pumpevents(eventdispatchthread.java:138)     @ java.awt.eventdispatchthread.run(eventdispatchthread.java:91) 

i want avoid user prompted security warning against jar when applet loaded, warning should appeared when button clicked.

nope. not option. security checks performed before app. makes on screen.