Why this applet not work ?
Please, someone can tell me why this applet not work ? I already signed it.
I realy need run this applet in IE4 with Microsoft JVM. I know all about the problem with JVM Microsoft but my client only have this platform !
--
import java.applet.Applet;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import com.ms.security.*;
public class Sec extends Applet {
public void init() {
PolicyEngine.assertPermission(PermissionID.NETIO);
byte[] buf = new byte[500];
try {
System.out.println("I will execute datagram socket.");
DatagramSocket ds = new DatagramSocket(6644);
DatagramPacket dp = new DatagramPacket(buf, 500);
ds.receive(dp);
System.err.println("Recebido:" + new String(buf));
} catch (Exception e) {
e.printStackTrace();
}
}
}
When the applet execute i take this message in Java console :
Microsoft (R) VM for Java, 5.0 Release 5.0.0.3805
==============================================
? ajuda
c limpar
f executar finalizadores
g coleta de lixo
m uso de mem髍ia
q fechar
t lista de segmentos
==============================================
I will execute datagram socket.
com.ms.security.SecurityExceptionEx[com/ibm/toolbar/Sec.init]: cannot access 6644
at com/ms/security/permissions/NetIOPermission.check
at com/ms/security/PolicyEngine.deepCheck
at com/ms/security/PolicyEngine.checkPermission
at com/ms/security/StandardSecurityManager.chk
at com/ms/security/StandardSecurityManager.checkListen
at java/net/DatagramSocket.create
at java/net/DatagramSocket.<init>
at java/net/DatagramSocket.<init>
at com/ibm/toolbar/Sec.init
at com/ms/applet/AppletPanel.securedCall0
at com/ms/applet/AppletPanel.securedCall
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.run
at java/lang/Thread.run
com.ms.security.SecurityExceptionEx[com/ibm/toolbar/Sec.init]: cannot access 6644
at java/net/DatagramSocket.CheckCanReceive
at java/net/DatagramSocket.receive
at com/ibm/toolbar/Sec.init
at com/ms/applet/AppletPanel.securedCall0
at com/ms/applet/AppletPanel.securedCall
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.run
at java/lang/Thread.run
com.ms.security.SecurityExceptionEx[com/ibm/toolbar/Sec.init]: cannot access 6644
at java/net/DatagramSocket.CheckCanReceive
at java/net/DatagramSocket.receive
at com/ibm/toolbar/Sec.init
at com/ms/applet/AppletPanel.securedCall0
at com/ms/applet/AppletPanel.securedCall
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.processSentEvent
at com/ms/applet/AppletPanel.run
at java/lang/Thread.run
Thanks...
[3070 byte] By [
jimmycw74a] at [2007-9-29 19:33:23]
i've been playing with applets and UDP, and have found that I do not need a signed applet :)
The applet will make a connection to the server the applet came from.
Here is sample code,
Sorry I do not know about MS jvm, but this does work with the latest java plugin.
public void start() {
try {
byte[] buffer = new byte[256];
URL url = getDocumentBase();
String host = url.getHost();
Socket socket = new Socket(host, 80);
InetAddress addr = socket.getLocalAddress();
DatagramSocket dsocket = null;
DatagramSocket dsocket1 = null;
DatagramPacket dpacket;
dsocket = new DatagramSocket(22222);
dsocket1 = new DatagramSocket(22223);
dpacket = new DatagramPacket(buffer,buffer.length, InetAddress.getByName("SERVER NAME HERE or IP"),8888); //i used ip
try{
dsocket.send(dpacket);
dsocket1.send(dpacket);
dsocket.receive(dpacket);
dsocket.close();
dsocket1.receive(dpacket);
dsocket1.close();
} catch (IOException ex){
addItem(ex.toString());
}
I ran a simple server code that would just relay packets back to where they came from.
Hi Jim,
I got the solution for the problem in the MSJVM environment. The fix is:
Regarding com.ms.security.SecurityExceptionEx you may find more information at the following link:
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q175/6/22.asp&NoWebContent=1
The exception may occur if an applet tries to do some forbidden action in
one of following places:
- default constructor, init(), start(), stop() or destroy() method. Proposed
work around is " start a thread and write the critical code in its run() method:"
So your code becomes;
import java.applet.Applet;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import com.ms.security.*;
public class Sec extends Applet {
public void init() {
Thread providerThread = new Thread(){
public void run(){
myFunction();
}
};
providerThread.start();
try {
providerThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
System.exit(-1);
}
}
private void myFunction() {
PolicyEngine.assertPermission(PermissionID.NETIO);
byte[] buf = new byte[500];
try {
System.out.println("I will execute datagram socket.");
DatagramSocket ds = new DatagramSocket(6644);
DatagramPacket dp = new DatagramPacket(buf, 500);
ds.receive(dp);
System.err.println("Recebido:" + new String(buf));
} catch (Exception e) {
e.printStackTrace();
}
}
}
Surely this will work:)
Thanks
Arun Govindan
Hello !
I followed your example and I tried the code below, but is not working. It gives the following exception :
Exception: com.ms.security.SecurityExceptionEx[Win32Cim_Threaded.myFunction]
Could you please advice me ?
Thank you in advance.
import java.sql.Connection;
//package WmiQueryInterface;
import com.ms.activeX.ActiveXComponent;
import com.ms.com.Dispatch;
import com.ms.com.Variant;
import java.applet.*;
import java.awt.*;
/**
* @author SPetit
*
* To change the template for this generated type comment go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
public class Win32Cim_Threaded extends Applet {
public static String text;
public void init() {
Thread providerThread = new Thread(){
public void run(){
myFunction();
}
};
providerThread.start();
try {
providerThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
System.exit(-1);
}
}
private void myFunction() {
try {
ActiveXComponent wmi = new ActiveXComponent ("WbemScripting.SWbemLocator");
//ActiveXComponent wmi = new ActiveXComponent("winmgmts:{impersonationLevel=impersonate}!\\\\127.0.0.1\\root\\cimv2");
text = "1234";
//this.showStatus("aaa");
//Object query = wmi.getObject();
//Object test = Dispatch.call(query,"ExecQuery","Select * From win32_process");
//Variant variant = new Variant(false);
//variant = Dispatch.get(test,"name");
//String text = variant.getString();
//this.showStatus(text);
//this.showStatus("aaa");
//new Win32Cim().paint1(g);
//System.out.println(variant);
}
catch (Exception e) {
System.out.println("Exception: "+e);
//this.showStatus("Exception: "+e);
}
}
}
