Java RMI or Servers

I want to have a server process running on a Windows computer as long as the computer is on, but a user is not necessarily logged in. I don't want to have someone have to go physically to the computer, but I want this to run automatically. How can this be done? Is there something like a "cron" job (Unix) for Windows?
Also, I want a Java process on Unix to connect to this Windows computer and run commands. How can the Windows process be sure that the authorized user is connecting to the environment? The thing is we are already inside a company within a firewall , protected from the outside world. However, within this project only 4-5 people should be able to run commands on the Windows computer, so how can I secure it in that manner?

On the Page: Making a UnicastRemoteObject Activatable
"This page is just for developers who wish to change an existing class from being a sub-class of UnicastRemoteObject to being a sub-class of java.rmi.activation.Activatable."
But then the second paragraph:
"Now with the introduction of the class java.rmi.activation.Activatable and the RMI daemon, rmid, programs can be written to register information about remote object implementations that should be created and execute "on demand," rather than running all the time. "
The second paragraph states that Activatable is for running on demand and this page says this page is for changing the class to a sub-class of Activatable.
I don't want something that can run on demand, I want it to run all the time.
Also, I have never written an RMI program before. I know basic Socket's to do a server/client program that way but never done RMI so maybe I'm lost with this Activatable stuff.

Similar Messages

Java.rmi.ConnectException

hi I am trying to connect to a remote server from my client as follows
$ java TestRcf -Djava.security.policy=policy
and my policy file is as follows....
grant {
permission java.net.SocketPermission "*:1024-65535", "connect";
I get the following error when i try to connect it...
Do i have to include anything else in the policy file or what is that i am missing?
the error is as follows......
lookup host: //10.1.129.3/RCFSearch10.1.129.3
java.rmi.ConnectException: Connection refused to host: 10.1.129.3; nested exception is:
java.net.ConnectException: Connection timed out
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:574)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:185)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:171)
at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:306)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Naming.java:84)
at com.lt.rcf.RemoteRCF.<init>(RemoteRCF.java:48)
at com.lt.rcf.RCFMediator.init(RCFMediator.java:405)
at com.lt.rcf.RCFMediator.<init>(RCFMediator.java:60)
at com.lt.rcf.RCFClient.<init>(RCFClient.java:59)
at com.lt.rcf.RCFAppBuilder.create(RCFAppBuilder.java:50)
at TestRcf.test0(TestRcf.java:55)
at TestRcf.main(TestRcf.java:88)
Caused by: java.net.ConnectException: Connection timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:364)
at java.net.Socket.connect(Socket.java:507)
at java.net.Socket.connect(Socket.java:457)
at java.net.Socket.<init>(Socket.java:365)
at java.net.Socket.<init>(Socket.java:178)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(RMIDirectSocketFactory.java:22)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(RMIMasterSocketFactory.java:128)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:569)
... 12 more
com.lt.rcf.RCFException: RCF Server connection not available: Connection refused to host: 10.1.129.3; nested exception is:
java.net.ConnectException: Connection timed out

first of all, which OS are you working on? This
question might sound wierd, but I have noticed a
lotta people working on Linux boxes havecomplained
about this. There is another mail thread about it:
>
http://forum.java.sun.com/thread.jspa?threadID=570065&
tstart=0
is your client able to look up the reference tothe
server ? If so, can you print that reference andfind
out which port the remote server is listening on ?
here did u mean Naming.LookUp("rmi://10.1.129.3") in the client.thats where i get connection refused while doing naming.lookup.
Then use the netstat command to see if the serveris
indeed listenign on that port when the connectionis
refused !
netstat -anp - p | grep <port_of_server>
let me know how it goes.
when i did netstat -anp - p | grep <port_of_server> on my client this is what i get ...
Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
tcp 0 0 0.0.0.0:1099 0.0.0.0:* LISTEN
6435/rmiregistry
tcp 0 0 10.1.129.3:51983 10.1.129.3:1099 ESTABLISHED
6492/java
tcp 0 0 10.1.129.3:1099 10.1.129.3:51983 ESTABLISHED
6435/rmiregistry

[b]Strange Java.rmi.ServerError[/b] (very Urgent)

I have a rmi application runninfg on one server (called 1), and web application accessing that application (running on JRUN 3.0) from onother server (called 2).
[ I am newly setting up this structure on another servers (fallback server).
Its working file in the existing servers (live server) ]
There is a perticular methode in a class for which i get the java.rmi.servererror nosuchmethodefound error. If i try any other methode it works fine. the erro only comes for that perticular methode.
I have check the class files (interface, implementation etc.) the methode is perfect and working on the other server.
There is no flow found in any code on any server (1 or 2).the code is perferct.
I can not fild the flaw so please help me its very urgent and criticle.
please help me on this

will the out of date interface or stub process other methodes and gives problem to perticular methode.
all other methodes in the class works fine its only that perticular methode gives me the problem.
I actualy recomplied every file and still the error is still there

Java.rmi.NoSuchObjectException problems

Hello,
After calling home.create() in my code, passing in primary key and
additional column data, when I call home.findByPrimaryKey (primkey)
followed by a call to one of the methods in the bean, I immediately get
a a java.rmi.NoSuchObjectException.
An exception is not thrown when calling home.findByPrimaryKey (primkey)
so it is safe to assume that a reference has been obtained to the bean
with the data I am looking for, correct? If so, why am I getting this
exception:
java.rmi.NoSuchObjectException: Bean with primary key: 'Pat Hardy' not
found in
home: 'Student'
at
weblogic.ejb.internal.EntityEJBContext.load(EntityEJBContext.java:153
at
weblogic.ejb.internal.EntityEJBContext.afterBegin(EntityEJBContext.ja
va:212)
at
weblogic.ejb.internal.StatefulEJBObject.getContextForInvoke(StatefulE
JBObject.java:162)
etc.
etc.
etc.
Any ideas of what I might be doing wrong?
Thanks for your help in advance.

We had a similar problem, although I don't know if it was the same
thing. We are using WL 5.1, sp5, with Oracle 8.1.6.
I have a stateless session bean, which had a transactional attribute
of 'Supports'. It would call an entity bean with transactional attribute
of 'RequiresNew' for all methods. The session bean would do a finder
on the entity bean, and if it got an ObjectNotFoundException, it would
then create the entity bean with a call to home.create(id). Then, it would
call a business method on the entity bean.
For some reason, in the case where the session bean is called from within
a thread that already had a transaction started, the call to the entity
bean business method would hang, if an only if it had to create a new
bean first. If the finder of the bean succeeded, there would be no hang.
Sometimes, instead of hanging, it would return a NoSuchObjectException.
If the stateless bean were called outside of a transaction, would always
succeed, regardless.
So, my fix, was to set the transactional attribute for the stateless bean to
'NotSupported' for all methods. It now seems to work in all cases,
no more hangs or NoSuchObjectExceptions....
Is this expected behavior? Is this related to the same problem?
The BEA recomendations to use READ-COMMITTED are useless for
the case where you are running a clustered environment, and where you
need to have the bean deployed on all servers in the cluster for
fail-over reliability.....
Jason
"Korey Shronts" <[email protected]> wrote in message
news:[email protected]...
I dont' know about the mapping to CHAR but we've managed to fix our nosuch
object problem.
BEA sent me this snippet:
The bug is as follows
In Oracle (8.0.5), if there is a primary key constraint AND you use an
isolation
level of SERIALIZABLE, an insert followed by an update in the same
transaction
fails. Specifically, the insert succeeds (to all outward indications),
but the update fails (the returned count is 0) after some number of
iterations.
What's the workaround? If the customer is not sharing the database with
any
other app or running it under a cluster, tell them to set the isolation
level to
read_committed. Serializable only slows them down without any added
benefit.
If clustering is on, and serializable behavior is deemed essential for
this
particular bean, maybe they can deploy the bean on only one of the
servers
to reduce it to the case above.
I set the isolation level on our beans to read_commited. Fixed theproblem
although we're using Oracle 8i not 8.0.5.
<[email protected]> wrote in message
news:[email protected]...
Well, it appears, that you cannot map a java.lang.String to a CHAR inOracle.
A java.lang.String can be mapped to a VARCHAR2.
Is this a bug?
[email protected] wrote:
I just install WebLogic server 5.1.0 and SP5 on a new machine.
Still have the same problems.
Will keep you posted.
Korey Shronts wrote:
We're having the same problem. I've opened a case with BEA but
haven't
heard anything yet. If you find the solution let me know!
[email protected]
<[email protected]> wrote in message
news:[email protected]...
I accidently omitted the first line in the exception. Sorry aboutthat.
Here it is again from the beginning:
Thu Sep 21 08:52:12 EDT 2000:<I> <EJB JAR deploymentC:/wlogic/lib/S.jar>
Transa
ction: '969540638993_1' rolled back due to EJB exception:
java.rmi.NoSuchObjectException: Bean with primary key: 'Pat Hardy'not
found in
home: 'Student'
at
weblogic.ejb.internal.EntityEJBContext.load(EntityEJBContext.java:153
at
weblogic.ejb.internal.EntityEJBContext.afterBegin(EntityEJBContext.ja
va:212)
at
weblogic.ejb.internal.StatefulEJBObject.getContextForInvoke(StatefulE
JBObject.java:162)
etc.
etc.
etc.
Any ideas of what I might be doing wrong?
Thanks for your help in advance.
[email protected] wrote:
Hello,
After calling home.create() in my code, passing in primary key
and
additional column data, when I call home.findByPrimaryKey(primkey)
followed by a call to one of the methods in the bean, Iimmediately get
a a java.rmi.NoSuchObjectException.
An exception is not thrown when calling home.findByPrimaryKey(primkey)
so it is safe to assume that a reference has been obtained to
the
bean
with the data I am looking for, correct? If so, why am I gettingthis
exception:
java.rmi.NoSuchObjectException: Bean with primary key: 'Pat
Hardy'
not
found in
home: 'Student'
at
weblogic.ejb.internal.EntityEJBContext.load(EntityEJBContext.java:153
at
weblogic.ejb.internal.EntityEJBContext.afterBegin(EntityEJBContext.ja
va:212)
at
weblogic.ejb.internal.StatefulEJBObject.getContextForInvoke(StatefulE
JBObject.java:162)
etc.
etc.
etc.
Any ideas of what I might be doing wrong?
Thanks for your help in advance.

Problem using CORBA clients with RMI/EJB servers..!!!???

Hi,
I have a question on using EJB / or RMI servers with CORBA clients using
RMI-IIOP transport, which in theory should work, but in practice has few
glitches.
Basically, I have implemented a very simple server, StockTreader, which
looks up for a symbol and returns a 'Stock' object. In the first example, I
simplified the 'Stock' object to be a mere java.lang.String, so that lookup
would simply return the 'synbol'.
Then I have implemented the above, as an RMI-IIOP server (case 1) and a
CORBA server (case 2) with respective clients, and the pair of
client-servers work fine as long as they are CORBA-to-CORBA and RMI-to-RMI.
But the problem arises when I tried using the RMI server (via IIOP) with the
CORBA client, when the client tries to narrow the object ref obtained from
the naming service into the CORBA idl defined type (StockTrader) it ends up
with a class cast exception.
This is what I did to achieve the above results:
[1] Define an RMI interface StockTrader.java (extending java.rmi.Remote)
with the method,
public String lookup( String symbol) throws RMIException;
[2] Implement the StorckTrader interface (on a PortableRemoteObject derived
class, to make it IIOP compliant), and then the server to register the stock
trader with COS Naming service as follows:
String homeName =....
StockTraderImpl trader =new StockTraderImpl();
System.out.println("binding obj <" homeName ">...");
java.util.Hashtable ht =new java.util.Hashtable();
ht.put("java.naming.factory.initial", args[2]);
ht.put("java.naming.provider.url", args[3]);
Context ctx =new InitialContext(ht);
ctx.rebind(homeName, trader);
[3] Generate the RMI-IIOP skeletons for the Implementation class,
rmic -iiop stock.StockTraderImpl
[4] generate the IDL for the RMI interface,
rmic -idl stock.StockTraderImpl
[5] Generate IDL stubs for the CORBA client,
idlj -v -fclient -emitAll StockTraderImpl.idl
[6] Write the client to use the IDL-defined stock trader,
String serverName =args[0];
String symList =args[1];
StockClient client =new StockClient();
System.out.println("init orb...");
ORB orb =ORB.init(args, null);
System.out.println("resolve init name service...");
org.omg.CORBA.Object objRef
=orb.resolve_initial_references("NameService");
NamingContext naming =NamingContextHelper.narrow(objRef);
... define a naming component etc...
org.omg.CORBA.Object obj =naming.resolve(...);
System.out.println("narrow objRef: " obj.getClass() ": " +obj);
StockTrader trader =StockTraderHelper.narrow(obj);
[7] Compile all the classes using Java 1.2.2
[8] start tnameserv (naming service), then the server to register the RMI
server obj
[9] Run the CORBA client, passing it the COSNaming service ref name (with
which the server obj is registered)
The CORBA client successfully finds the server obj ref in the naming
service, the operation StockTraderHelper.narrow() fails in the segment
below, with a class cast exception:
org.omg.CORBA.Object obj =naming.resolve(...);
StockTrader trader =StockTraderHelper.narrow(obj);
The <obj> returned by naming service turns out to be of the type;
class com.sun.rmi.iiop.CDRInputStream$1
This is of the same type when stock trader object is registered in a CORBA
server (as opposed to an RMI server), but works correctly with no casting
excpetions..
Any ideas / hints very welcome.
thanks in advance,
-hari

On the contrary... all that is being said is that we needed to provide clearer examples/documentation in the 5.1.0 release. There will be no difference between the product as found in the service pack and the product found in the 5.1.1. That is, the only substantive will be that 5.1.1 will also
include the examples.
"<=one way=>" wrote:
With reference to your and other messages, it appears that one should not
expect that WLS RMI-IIOP will work in a complex real-life system, at least
not now. In other words, support for real-life CORBA clients is not an
option in the current release of WLS.
TIA
"Eduardo Ceballos" <[email protected]> wrote in message
news:[email protected]...
We currently publish an IDL example, even though the IDL programmingmodel in Java is completely non-functional, in anticipation of the support
needs for uses who need to use IDL to talk to the Weblogic server,
generically. This example illustrates the simplest connectivity; it does not
address how
to integrate CORBA and EJB, a broad topic, fraught with peril, imo. I'llnote in passing that, to my knowledge, none of the other vendors attempt
this topic either, a point which is telling if all the less happy to hear.
For the record then, what is missing from our distribution wrt RMI-IIOPare a RMI-IIOP example, an EJB-IIOP example, an EJB-C++. In this you are
correct; better examples are forth coming.
Still, I would not call our RMI-IIOP implementation fragile. I would saythat customers have an understandably hard time accepting that the IDL
programming model is busted; busted in the sense that there are no C++
libraries to support the EJB model, and busted in the sense that there is
simply no
support in Java for an IDL interface to an EJB. Weblogic has nothing to doit being busted, although we are trying to help our customers deal with it
in productive ways.
For the moment, what there is is a RMI (over IIOP) programming model, aninherently Java to Java programming model, and true to that, we accept and
dispatch IIOP request into RMI server objects. The way I look at it is this:
it's just a protocol, like HTTP, or JRMP; it's not IDL and it has
practically nothing to do with CORBA.
ST wrote:
Eduardo,
Can you give us more details about the comment below:
I fear that as soon as the call to narrow succeeds, the remainingapplication will fail to work correctly because it is too difficult ot
use an idl client in java to work.It seems to me that Weblogic's RMI-IIOP is a very fragile
implementation. We
don't need a "HelloWorld" example, we need a concrete serious example(fully
tested and seriously documented) that works so that we can get a betteridea
on how to integrate CORBA and EJB.
Thanks,
Said
"Eduardo Ceballos" <[email protected]> wrote in message
news:[email protected]...
Please post request to the news group...
As I said, you must separate the idl related classes (class files and
java
files) from the rmi classes... in the rmic step, you must set a newtarget
(as you did), emit the java files into that directory (it's not clearyou
did this), then remove all the rmi class files from the class path... ifyou
need to compile more classes at that point, copy the java files to theidl
directly is you must, but you can not share the types in any way.
I fear that as soon as the call to narrow succeeds, the remainingapplication will fail to work correctly because it is too difficult otuse
an idl client in java to work.
Harindra Rajapakshe wrote:
Hi Eduardo,
Thanks for the help. That is the way I compiled my CORBA client, by
separating the IDL-generated stubs from the RMI ones, but still I
get a
CORBA.BAD_PARAM upon narrowing the client proxy to the interfacetype.
Here's what I did;
+ Define the RMI interfaces, in this case a StockTrader interface.
+ Implement RMI interface by extendingjavax.rmi.PortableRemoteObject
making
it IIOP compliant
+ Implemnnt an RMI server, and compile using JDK1.2.2
+ use the RMI implementation to generate CORBA idl, using RMI-IIOPplugin
utility rmic;
rmic -idl -noValueMethods -always -d idl stock.StockTraderImpl
+ generate Java mappings to the IDL generated above, using RMI-IIOPplugin
util,
idlj -v -fclient -emitAll -tf src stocks\StockTrader.idl
This creates source for the package stock and also
org.omg.CORBA.*
package, presumably IIOP type marshalling
+ compile all classes generated above using JDK1.2.2
+ Implement client (CORBA) using the classes generated above, NOTthe
RMI
proxies.
+ start RMI server, with stockTrader server obj
+ start tnameserv
+ start CORBA client
Then the client errors when trying to narrow the obj ref from the
naming
service, into the CORBA IDL defined interface using,
org.omg.CORBA.Object obj =naming.resolve(nn);
StockTrader trader =StockTraderHelper.narrow(obj); // THIS
ERRORS..!!!
throwing a CORBA.BAD_PARAM exception.
any ideas..?
Thanks in advance,
-hari
----- Original Message -----
From: Eduardo Ceballos <[email protected]>
Newsgroups: weblogic.developer.interest.rmi-iiop
To: Hari Rajapakshe <[email protected]>
Sent: Wednesday, July 26, 2000 4:38 AM
Subject: Re: problem using CORBA clients with RMI/EJBservers..!!!???
Please see the post on june 26, re Errors compiling... somewherein
there,
I suspect, you are referring to the rmi class file when you are
obliged
to
completely segregate these from the idl class files.
Hari Rajapakshe wrote:
Hi,
I have a question on using EJB / or RMI servers with CORBA
clients
using
RMI-IIOP transport, which in theory should work, but in practice
has
few
glitches.
Basically, I have implemented a very simple server,
StockTreader,
which
looks up for a symbol and returns a 'Stock' object. In the firstexample, I
simplified the 'Stock' object to be a mere java.lang.String, so
that
lookup
would simply return the 'synbol'.
Then I have implemented the above, as an RMI-IIOP server (case
1)
and a
CORBA server (case 2) with respective clients, and the pair of
client-servers work fine as long as they are CORBA-to-CORBA andRMI-to-RMI.
But the problem arises when I tried using the RMI server (via
IIOP)
with
the
CORBA client, when the client tries to narrow the object ref
obtained
from
the naming service into the CORBA idl defined type (StockTrader)
it
ends
up
with a class cast exception.
This is what I did to achieve the above results:
[1] Define an RMI interface StockTrader.java (extending
java.rmi.Remote)
with the method,
public String lookup( String symbol) throws RMIException;
[2] Implement the StorckTrader interface (on a
PortableRemoteObject
derived
class, to make it IIOP compliant), and then the server to
register
the
stock
trader with COS Naming service as follows:
String homeName =....
StockTraderImpl trader =new StockTraderImpl();
System.out.println("binding obj <" homeName ">...");
java.util.Hashtable ht =new java.util.Hashtable();
ht.put("java.naming.factory.initial", args[2]);
ht.put("java.naming.provider.url", args[3]);
Context ctx =new InitialContext(ht);
ctx.rebind(homeName, trader);
[3] Generate the RMI-IIOP skeletons for the Implementation
class,
rmic -iiop stock.StockTraderImpl
[4] generate the IDL for the RMI interface,
rmic -idl stock.StockTraderImpl
[5] Generate IDL stubs for the CORBA client,
idlj -v -fclient -emitAll StockTraderImpl.idl
[6] Write the client to use the IDL-defined stock trader,
String serverName =args[0];
String symList =args[1];
StockClient client =new StockClient();
System.out.println("init orb...");
ORB orb =ORB.init(args, null);
System.out.println("resolve init name service...");
org.omg.CORBA.Object objRef
=orb.resolve_initial_references("NameService");
NamingContext naming=NamingContextHelper.narrow(objRef);
... define a naming component etc...
org.omg.CORBA.Object obj =naming.resolve(...);
System.out.println("narrow objRef: " obj.getClass() ":"
+obj);
StockTrader trader =StockTraderHelper.narrow(obj);
[7] Compile all the classes using Java 1.2.2
[8] start tnameserv (naming service), then the server to
register
the
RMI
server obj
[9] Run the CORBA client, passing it the COSNaming service ref
name
(with
which the server obj is registered)
The CORBA client successfully finds the server obj ref in the
naming
service, the operation StockTraderHelper.narrow() fails in thesegment
below, with a class cast exception:
org.omg.CORBA.Object obj =naming.resolve(...);
StockTrader trader =StockTraderHelper.narrow(obj);
The <obj> returned by naming service turns out to be of the
type;
class com.sun.rmi.iiop.CDRInputStream$1
This is of the same type when stock trader object is registeredin a
CORBA
server (as opposed to an RMI server), but works correctly with
no
casting
excpetions..
Any ideas / hints very welcome.
thanks in advance,
-hari

Java.rmi.MarshalException: Exception

hi,
i am getting the below error while displaying the data from a servlet. Here in servlet i had written the code to store values. And then i had written a function "getDetails()" which will give result set object. At that time i am getting this error. This method code is in bena class.
In servlet this is the code i had wriiten
InitialContext initContext=new InitialContext();
                    home=(InsuranceHome)initContext.lookup(ejbJndiName);
                    remote=home.create();
                    int n=remote.insertDetails(cname,frm_date,to_date,type,ppaid,rmks);
                    ResultSet rs=remote.getResults();
                    while(rs.next())
                         System.out.print(rs.getString(1));
                         System.out.print(rs.getString(2));
                         System.out.print(rs.getString(3));
                         System.out.println(rs.getString(4));
                    System.out.println(n);
[10/Apr/2008:11:34:06] INFO ( 3108): CORE3282: stdout:      java.rmi.MarshalException: Exception occurred in server thread; nested exception is:
[10/Apr/2008:11:34:06] INFO ( 3108): CORE3282: stdout:      java.io.NotSerializableException

the NEVER used here, is it an EJB specification issue or design issue. If EJB specification issue then you should be right of which i am not sure. Please quote reference.
If design issue then NEVER is wrong. Its depends on task to be addressed. Data Transfer Pattern allows the use of Rowset to exchange data between clients and servers.These options are either DTOs, containers, RowSets all are serializabel.How will you managed bandwidth and memory issues in a critical application where by clients needs to get a copy of data store in their memory(delete,update, insert) and after finished with their task they simply click synchronized.
this copy(rowset) in client is simply sent to sever for updates rather than doing update, insert, delete request to server for every operation.
This is a pattern design issue and the choice of Data Transfer Object depends on the task and type of communication between clients and server.
A RowSet in the situation whereby 1. number of request to server has to be reduced, 2. connection to server has to be minimal. 3. each client gets a copy of his data as a snapshot of server contents processed it an then do synchronization when needed(bulk).Also this is issued when memory of client is a big issue like mobiles so installing a DB on the mobile is not possible. The rowset sent to client must not hold a connection to DB.
Ivo Sumelong

Help urgently needed with Java RMI task.

Hello All. Please I need help urgently with this task. I cant seem to be able to do this. Here is the task:
There are m squares with side lengths a1, a2, ..., am and a rectangle with the height and width equal to h and w respectively. Find a subset of the squares, which must be placed within the rectangle in such a way that they do not overlap, and cover the maximum area of a rectangle.*
Please all help me solve this task using Java RMI. I would be very grateful for your help. Thanks in advance.

Here is my client.java.
import compute.;*
import java.lang.Math.;*
import java.lang.Long;
*public class Hypothesis implements Task {*
private long start;
private long end;
private int number;
private int count;
public Hypothesis(long start, long end, int number,int
*count) {*
this.start = start;
this.end = end;
this.number = number;
this.count = count;
*public Object execute() {*
return findSolution();
*public String findSolution() {*
long i,j,k,l,m=1,i_max,j_max,k_max,l_max,l_start;
System.out.println(start);
System.out.println(end);
System.out.println(number);
System.out.println(count);
for(m=start+number;m<end;m+=count)
i_max=(long)java.lang.Math.pow((double)(min(p5(m)-3)),0.2d)+1;
for(i=i_max;i>0;i--)
j_max=(long)java.lang.Math.pow((double)(min(p5(m)-p5(i)-2)),0.2d)+1;
if (j_max>i) j_max=i;
for(j=j_max;j>0;j--)
k_max=(long)java.lang.Math.pow((double)(min(p5(m)-p5(i)-p5(j)-1)),0.2d)+1;
if (k_max>j) k_max=j;
for(k=k_max;k>0;k--)
l_max=(long)java.lang.Math.pow((double)(min(p5(m)-p5(i)-p5(j)-p5k))),0.2d)+1;
if (l_max>k) l_max=k;
if (l_max>2) l_start=l_max-2;
else l_start=1;
for(l=l_max;l>l_start-1;l--)
if(p5(i)+p5(j)+p5(k)+p5(l)==p5(m))
Long[] solution=new Long[5];
solution[0]=i;
solution[1]=j;
solution[2]=k;
solution[3]=l;
solution[4]=m;
*return "" solution[0]"^5+"*
solution[1]"^5+"*
solution[2]"^5+"*
solution[3]"^5="*
solution[4]"^5";*
return null;
*private long p5(long n){*
return nn*n*n*n;*
*private long min(long n){*
return n>0?n:0;
I just can't seem to get the whole thing work correctly on the server side. I need it to run from 1 client on atleast 3 servers. Please any explanations will be appreciated.

Distributed architecture using JAVA RMI

Hi!
I want to implement a distributed architecture, in which clients invoke any of several servers, depending on their availability. The clients are not browsers, so web-server (e.g. Tomcat) clustering is not relevant here. It's a cluster of servers, each capable of providing the same functionality, but clients should be able to "find" the less loaded one and invoke it. Now, with EJB's I believe this is provided out-of-the-box, but what about using RMI? How do two processes find each other via RMI, and is it possible to put a load-balancer in the middle?
Is it possible to setup a load-balancer IP as RMI host endpoint?
Thanks a lot
A.

They find one another using the rmiregistry tool from the JDK bin, which servers register with and clients use as a lookup. AFAIK this doesn't provide provision for anything resembling load balancing. Java RMI is a fairly basic facility.
You should probably take a look at a framework like osgi.

Java.rmi.ConnectException: Could not establish...

          I have realized a Cluster on WLS 6.1 sp4 but failover doesn't works fine.
          After the fail of the first node , the application goes on the secondary and works
          fine ... when the second node fails the http session goes on the third node but
          my application crash with this stack trace : <7-mar-03 19.30.03 CET> <Info> <Cluster>
          <Removing
          5110730417871414485S:192.168.120.35:[7009,7009,7010,7010,7009,7010,-1]:192.1
          68.12
          0.35,192.168.120.39,192.168.120.222,192.168.120.223:mydomain:nodo1 to the
          cluster>
          <7-mar-03 19.30.14 CET> <Info> <HTTP>
          <[WebAppServletContext(4776087,portale,/portale)] Localita: init>
          [PrimarySecondaryReplicaHandler] :
          weblogic.rmi.internal.LeasedRemoteRef@159 - jvmid:
          '5110730417871414485S:192.168.120.35:[7009,700
          9,7010,7010,7009,7010,-1]:192.168.120.35,192.168.120.39,192.168.120.222,192.
          168.120.223:mydomain:nodo1', oid: '345'
          java.rmi.ConnectException: Could not establish a connection with
          5110730417871414485S:192.168.120.35:[7009,7009,7010,7010,7009,7010,
          -1]:192.168.120.35,192.168.120.39,192.168.120.222,192.168.120.223:mydomain:n
          odo1, java.rmi.ConnectException: Destination unreachable
          ; nested exception is:
          java.net.ConnectException: Connection refused; No available router
          to destination
          at weblogic.rjvm.RJVMImpl.getOutputStream(RJVMImpl.java:275)
          at weblogic.rjvm.RJVMImpl.getRequestStream(RJVMImpl.java:408)
          at
          weblogic.rmi.internal.BasicRemoteRef.getOutboundRequest(BasicRemoteRef.java:
          97)
          at
          weblogic.rmi.cluster.ReplicaAwareRemoteRef.invoke(ReplicaAwareRemoteRef.java
          :255)
          at
          weblogic.rmi.cluster.ReplicaAwareRemoteRef.invoke(ReplicaAwareRemoteRef.java
          :230)
          at weblogic.rmi.internal.ProxyStub.invoke(ProxyStub.java:35)
          at $Proxy165.getFunzioneCorrente(Unknown Source)
          at dbr.servlet.FunzioneServlet.doGetOrPost(FunzioneServlet.java:126)
          at dbr.servlet.FunzioneServlet.doPost(FunzioneServlet.java:49)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
          at
          weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java
          :262)
          at
          weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java
          :198)
          at
          weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletCo
          ntext.java:2637)
          at
          weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java
          :2359)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:139)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:120)
          <7-mar-03 19.30.15 CET> <Debug> <DBR-TIM> <Could not establish a connection
          with 5110730417871414485S:192.168.120.35:[7009,7009,7010
          ,7010,7009,7010,-1]:192.168.120.35,192.168.120.39,192.168.120.222,192.168.12
          0.223:mydomain:nodo1, java.rmi.ConnectException: Destina
          tion unreachable; nested exception is:
          java.net.ConnectException: Connection refused; No available router
          to destination>
          it looks like the secondary don't trasform himself in a primary , looking for
          ejb stub on the node died.
          Thanks for any help.


Hi, I got the solution. Now it is working. Need to set the 'Listen Address:' environment parameter of the weblogic Admin server with the IP address of the machine on which the EJBs' are deployed. The path to this parameter on the console is - 'base_domain/Environment/Servers/'. Under this select your server and under configuration tab and General sub tab.

Error: while generating SQL.java.rmi.ServerException:

Hi:
I tried the JGuru's "MusicStore" example. HOwever at Task 6 and 7 I am getting the following error:
Error: while generating SQL.java.rmi.ServerException:
RemoteException occured in server thread; nested exception is:
* java.rmi.RemoteException: Error connecting to database;
nested exception is:
* SQL Exception: Failed to start database 'MusicStoreDB', see
the next exception for details.
Please make sure the database name/user/password is valid
and the J2ee server and database are running.
However when i check my database it is running perfectly:
E:\>%j2ee_home%\bin\cloudscape -start
Sun Feb 16 12:48:11 PST 2003: [RmiJdbc] Starting Cloudscape RmiJdbc Server Version
Sun Feb 16 12:48:14 PST 2003: [RmiJdbc] COM.cloudscape.core.JDBCDriver registered i
Sun Feb 16 12:48:14 PST 2003: [RmiJdbc] Binding RmiJdbcServer...
Sun Feb 16 12:48:14 PST 2003: [RmiJdbc] No installation of RMI Security Manager...
Sun Feb 16 12:48:14 PST 2003: [RmiJdbc] RmiJdbcServer bound in rmi registry
Server:
J2EE server listen port: 1050
Naming service started:1050
Binding DataSource, name = jdbc/DB2, url = jdbc:cloudscape:rmi:CloudscapeDB;crea
te=true
Binding DataSource, name = jdbc/Cloudscape, url = jdbc:cloudscape:rmi:Cloudscape
DB;create=true
Binding DataSource, name = jdbc/InventoryDB, url = jdbc:cloudscape:rmi:Cloudscap
eDB;create=true
Binding DataSource, name = jdbc/DB1, url = jdbc:cloudscape:rmi:CloudscapeDB;crea
te=true
Binding DataSource, name = jdbc/MusicStore, url = jdbc:cloudscape:rmi:MusicStore
DB;create=false
Binding DataSource, name = jdbc/XACloudscape, url = jdbc/XACloudscape__xa
Binding DataSource, name = jdbc/XACloudscape__xa, dataSource = COM.cloudscape.co
re.RemoteXaDataSource@1d88db7
Starting JMS service...
Initialization complete - waiting for client requests
Binding: < JMS Destination : jms/Topic , javax.jms.Topic >
Binding: < JMS Destination : jms/Queue , javax.jms.Queue >
Binding: < JMS Cnx Factory : TopicConnectionFactory , Topic , No properties >
Binding: < JMS Cnx Factory : QueueConnectionFactory , Queue , No properties >
Binding: < JMS Cnx Factory : jms/QueueConnectionFactory , Queue , No properties
>
Binding: < JMS Cnx Factory : jms/TopicConnectionFactory , Topic , No properties
>
Starting web service at port: 8000
Starting secure web service at port: 7000
J2EE SDK/1.3.1
Starting web service at port: 9191
J2EE SDK/1.3.1
J2EE server startup complete.
Can anyone suggest me a way out..plz

what type of persistent u r using also post ur query if bmp and check with another example with cmp.

Java.rmi.RemoteException: EJB Exception: while calling an EJB method,

Hi
I am getting below error while calling a stateless EJB method. There is some validation checks while performing ejb's modify() method and a RuntimeException is thrown in case of validation failure.The modify() method internally calls other stateless ejb as well.
The problem I'm facing is, instead of getting the expected RuntimeException in the Servlet, i am getting RemoteException. I am using WLS 9 MP1, all participating ejbs are stateless and i am using default transaction attributes(Supports) for these ejbs.
The interesting part is, at the ejb layer RuntimeException is thrown as expected, but this exception changed to RemoteException at the servlet's end where i am catching the ejb call exceptions.
I am new to WLS, please suggest/help me out of this exception.
Any help is truly appreciated.
java.rmi.RemoteException: EJB Exception: ; nested exception is: java.lang.RuntimeException:
     at weblogic.ejb.container.internal.EJBRuntimeUtils.throwRemoteException(EJBRuntimeUtils.java:95)
     at weblogic.ejb.container.internal.BaseEJBObject.handleSystemException(BaseEJBObject.java:713)
     at weblogic.ejb.container.internal.BaseEJBObject.handleSystemException(BaseEJBObject.java:681)
     at weblogic.ejb.container.internal.BaseEJBObject.postInvoke1(BaseEJBObject.java:447)
     at weblogic.ejb.container.internal.StatelessEJBObject.postInvoke1(StatelessEJBObject.java:72)
     at weblogic.ejb.container.internal.BaseEJBObject.postInvokeTxRetry(BaseEJBObject.java:374)
     at com.mycomp.base.BaseController_8x2e52_EOImpl.modify(BaseController_8x2e52_EOImpl.java:149)
     at com.mycomp.webgui.servlet.FrontComponent.service(FrontComponent.java:207)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
     at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:223)
     at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:283)
     at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:175)
     at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3245)
     at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
     at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:121)
     at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2003)
     at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:1909)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1359)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:209)
     at weblogic.work.ExecuteThread.run(ExecuteThread.java:181)
Thanks!
Edited by: user10721298 on Feb 23, 2009 4:16 AM

Hi,
If i don't misunderstand, you are using the RuntimeException as an application exception, right?
Have you annotated it or denoted it in deployment descriptor?
Thanks,
Amy

Java.rmi.RemoteException: SOAP Fault:javax.xml.rpc.soap.SOAPFaultException

Hi, I created a webservice using weblogic8.1 sp3 workshop. On my desktop, I tested the webservice with a java client and it worked fine. When I deployed webservice application on UNIX production server, it deployed successfully and it displayed WSDL file too. But, when I run java client from desktop to access this webservice on UNIX server, it is throwing the following exception.
java.rmi.RemoteException: SOAP Fault:javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
Detail:
<detail>
null </detail>; nested exception is:
javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
at weblogic.jws.proxies.MyServiceSoap_Stub.getInfo(MyServiceSoap_Stub.java:31)
at SoapClient.main(SoapClient.java:17)
Caused by: javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
at weblogic.webservice.core.ClientDispather.receive(ClientDispatcher.java:313)
at weblogic.webservice.core.ClientDispatcher.dispatch(ClientDispatcher.java:144)
at weblogic.webservice.core.DefaultOperation.invoke(DefaultOperation.java:457)
at weblogic.webservice.core.DefaultOperation.invoke(DefaultOperation.java:443)
at weblogic.webservice.core.rpc.StubImpl._invoke(StubImpl.java:290)
at weblogic.jws.proxies.MyServiceSoap_Stub.getInfo(MyServiceSoap_Stub.java:26)
can somebody please help me. This is very critical for me.
Thanks in advance.

Hi, I created a webservice using weblogic8.1 sp3 workshop. On my desktop, I tested the webservice with a java client and it worked fine. When I deployed webservice application on UNIX production server, it deployed successfully and it displayed WSDL file too. But, when I run java client from desktop to access this webservice on UNIX server, it is throwing the following exception.
java.rmi.RemoteException: SOAP Fault:javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
Detail:
<detail>
null </detail>; nested exception is:
javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
at weblogic.jws.proxies.MyServiceSoap_Stub.getInfo(MyServiceSoap_Stub.java:31)
at SoapClient.main(SoapClient.java:17)
Caused by: javax.xml.rpc.soap.SOAPFaultException: EXCEPTION: java.lang.NoClassDefFoundError [ServiceException]
at weblogic.webservice.core.ClientDispather.receive(ClientDispatcher.java:313)
at weblogic.webservice.core.ClientDispatcher.dispatch(ClientDispatcher.java:144)
at weblogic.webservice.core.DefaultOperation.invoke(DefaultOperation.java:457)
at weblogic.webservice.core.DefaultOperation.invoke(DefaultOperation.java:443)
at weblogic.webservice.core.rpc.StubImpl._invoke(StubImpl.java:290)
at weblogic.jws.proxies.MyServiceSoap_Stub.getInfo(MyServiceSoap_Stub.java:26)
can somebody please help me. This is very critical for me.
Thanks in advance.

Problem while Deploying WebDynpro application-error:java.rmi.RemoteExceptio

Hi All,
i installed WAS 6.40 sp 16 on my system its working fine. I can able to log in to the SDM as remoteGUI.bat using my sdm password.But while deploying the webdynpro appliation i am getting error like "java.rmi.RemoteException: Only Administrators have the right to perform this operation".
Using my administrator PWD i can log in to all the systems like Useradmin, SDM, J2E engine.
can any one help me....thanks in advance

hi all
i also had the same problem, i am able to log into SDM GUI through Remotegui.bat
but even though i had changed the password i am not able to deploy the applicaton to j2ee sever, through the NWDS. I tried deploying the applicaton in the
GUI of SDM there also it is giving like "Only Administrators have the right to perform this operation".
How to go to User Administration and where?is it in OS level or in Web AS Admin console?
Adding user admin (default password is also admin) to the Administrators group,
Go to: User Administration --> Groups and search for Administrators.
Then add user with ID admin in this group

Java.rmi.ServerException: Server unavailable, please try later

I'm testing a service proxy in JDeveloper 10.1.3.1.
I'm using encryption and signing.
Now that I have the encryption/signing key loading, I get the following error:
WARNING: Subject Key ID extension not found.Using BST Referencing scheme
java.rmi.ServerException:
start fault message:
Server unavailable, please try later
:end fault message
     at oracle.j2ee.ws.client.StreamingSender._raiseFault(StreamingSender.java:560)
     at oracle.j2ee.ws.client.StreamingSender._sendImpl(StreamingSender.java:396)
     at oracle.j2ee.ws.client.StreamingSender._send(StreamingSender.java:112)
     at pkg.service.client.runtime.RequestSoap_Stub.execute(RequestSoap_Stub.java:84)
     at pkg.service.client.RequestSoapClient.execute(RequestSoapClient.java:48)
     at pkg.service.client.RequestSoapClient.main(RequestSoapClient.java:34)
Process exited.
Debugger disconnected from local process.
Is this a failure of the RMI server on my side or is it a failure to connect to the service? Is the destination service sending this to me or just the transmission code?
It looks to me from the trace and the vagueness of the message that this is from the Oracle transmission code in the StreamingSender class, not a message received from the destination webservice. Would love some confirmation, though.
Thanks for any help.

This error generally means there is trouble in the host file, or there is trouble with anti-virus software. Check this section of the support document that you came here from.
Unable to contact the iOS software update server gs.apple.com
Error 1004, 1013, 1638, 3014, 3194: These errors may be the result of the connection to gs.apple.com being redirected or blocked. Follow these steps to resolve these errors:
Install the latest version of iTunes.
Check security software. Ensure that communication to gs.apple.com is allowed. Follow this article for assistance with security software. iTunes for Windows: Troubleshooting security software issues.
Check the hosts file. The restore will fail if there is an active entry to redirect gs.apple.com. Follow iTunes: Advanced iTunes Store troubleshooting to edit the hosts file or revert to a default hosts file. See section "Blocked by configuration: (Mac OS X/Windows) > Rebuild network information".
Try to restore from another known-good computer and network.
If the errors persist on another computer, the device may need service.

Java.rmi.ServerException:

I am new to RMI concept
i stuck with the below problem
when i execute
E:\MyProjects\StockRMI>java -Djava.security.policy=policy.all StockMarketServerStockMarketServer is as shown below
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject;
import SimpleStocks.*;
public class StockMarketServer {
public static void main(String[] args) throws Exception {
    if(System.getSecurityManager() == null) {
      System.setSecurityManager( new RMISecurityManager() );
    StockMarketImpl myObject = new StockMarketImpl( "NASDAQ" );
    System.out.println( "RMI StockMarketServer ready..." );
} i got the following error
java.rmi.ServerException: RemoteException occurred in server thread; nested exce
ption is:
        java.rmi.UnmarshalException: error unmarshalling arguments; nested excep
tion is:
        java.lang.ClassNotFoundException: SimpleStocks.StockMarketImpl_Stub
RMI StockMarketServer ready...Interface class, Interface implementation class and stub all reside in MyProjects\StockRMI\SimpleStocks directory
where as Server class(StockMarkerServer) is in MyProjects\StockRMI
even i place the stub in MyProjects\StockRMI directory i got the same error.
Can any one please save me out of this problem

hurry!
Thank u First of all
I got it.. finally after 2 days
The error is in CLASSPATH only , i set it
Thanks once again

Java RMI or Servers

Similar Messages

Maybe you are looking for