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Java denying access to property permissions

new to parallel/distributed computing and having issues with a client-server program I'm trying to write. What's supposed to happen is the server receives an integer from the client and sends back the sum all the numbers leading up to it (ex, user enters 5, server calculates 1+2+3+4+5, server sends back 15). I'm still trying to figure it out, so I've hard coded the input on the client side.
This is what I have on the server side:
import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
import java.net.*;
import java.util.*;
public class Server {
public static void main(String[]args) {
try{
int port = 16790;
String host = "localhost";
CalculateSumServerImpl export = new CalculateSumServerImpl();
LocateRegistry.createRegistry(port);
String registryURL = "rmi://" + host + ":" + port + "/sum";
Naming.rebind(registryURL, export);
System.out.println("Server ready");
} catch (Exception e) {
e.printStackTrace();
}
} }
//to calculate the sum
import java.rmi.*;
import java.rmi.server.*;
public class CalculateSumServerImpl extends UnicastRemoteObject implements CalServerInterface {
public int n; //value entered
public int sum; //sum
protected CalculateSumServerImpl() throws RemoteException {
super();
}
#Override
public int calculateSum(int n) throws RemoteException {
n = (n*(n+1))/2; //sum of 1 + 2 + 3 + .. + n
sum = n;
return sum;
} }
//interface
import java.rmi.Remote;
public interface CalServerInterface extends Remote {
public int calculateSum(int n ) throws java.rmi.RemoteException;
}
And on the client side:
import java.rmi.*;
import java.util.PropertyPermission;
public class Client {
public static void main(String[]args) {
System.setSecurityManager(new java.rmi.RMISecurityManager());
System.setProperty("java.net.preferIPv4Stack" , "true");
try {
int port = 16790;
String host = "localhost";
String registryURL = "rmi://" + host + ":" + port + "/sum";
Project4ServerInterface obj = (Project4ServerInterface)Naming.lookup(registryURL);
System.out.println("Lookup completed.");
int output = obj.calculateSum(3);
System.out.println("Sum is: " + output);
} catch (Exception e) {
e.printStackTrace();
}
System.setProperty("java.net.preferIPv4Stack","true");
} }
And I've implemented the Interface on the client side as well.
The error that I've been getting on the client side is:
Exception in thread "main" java.security.AccessControlException: access denied ("java.util.PropertyPermission" "java.net.preferIPv4Stack" "write")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:472)
at java.security.AccessController.checkPermission(AccessController.java:884)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at java.lang.System.setProperty(System.java:792)
at project04client.Client.main(Client.java:10)
with the error pointing to the line with this code:
System.setProperty("java.net.preferIPv4Stack" , "true");
Anyone have any experience trouble shooting this error?
Thanks!

The problem is that you have set a security manager for the entire (client) application that won't let you modify system properties.
The simple fix is to set the system properties you need to set before you set the RMI security manager.
Alternatively, you may be able to get rid of the System.setSecurityManager(...) call entirely. You (probably) only need it if you want the client to be able to download classes from your RMI service.
I tried setting the system property before the security manager and got an AccessControlException, denying socket permissions.
That doesn't make much sense. You would only get an AccessControlException if there was a security manager in place at that point. There shouldn't be ... unless this is applet code or similar launched in a web browser. Also, I don't know why a call to set a property would be denied saying that you don't have socket permissions.
When I took the security manager out completely, I got an UnmarshalException pointing to the interface.
You also need to add the classes / interfaces for the objects that tou will be unmarshalling to the client-side classpath.
Actually, I just noticed that the javadoc for RMISecurityManager says:
"RMISecurityManager implements a policy identical to the policy implemented by SecurityManager. RMI applications should use the SecurityManager class or another appropriate SecurityManager implementation instead of this class."

ZooKeeper for Java/Spring Config?

Are there any well documented use cases of Apache ZooKeeper being used to distribute configuration of Java applications, and in particular Spring services?
Like many users of cloud services I have a requirement to change the configuration of a variable amount of Java services, preferably at run-time without needing to restart the services.
UPDATE
Eventually I ended up writing something that would load a ZooKeeper node as a properties file, and create a ResourcePropertySource and insert it into a Spring context. Note that this will not reflect changes in the ZooKeeper node after the context has started.
public class ZooKeeperPropertiesApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
private static final Logger logger = LoggerFactory.getLogger(ZooKeeperPropertiesApplicationContextInitializer.class);
private final CuratorFramework curator;
private String projectName;
private String projectVersion;
public ZooKeeperPropertiesApplicationContextInitializer() throws IOException {
logger.trace("Attempting to construct CuratorFramework instance");
RetryPolicy retryPolicy = new ExponentialBackoffRetry(10, 100);
curator = CuratorFrameworkFactory.newClient("zookeeper", retryPolicy);
curator.start();
}
/**
* Add a primary property source to the application context, populated from
* a pre-existing ZooKeeper node.
*/
#Override
public void initialize(ConfigurableApplicationContext applicationContext) {
logger.trace("Attempting to add ZooKeeper-derived properties to ApplicationContext PropertySources");
try {
populateProjectProperties();
Properties properties = populatePropertiesFromZooKeeper();
PropertiesPropertySource propertySource = new PropertiesPropertySource("zookeeper", properties);
applicationContext.getEnvironment().getPropertySources().addFirst(propertySource);
logger.debug("Added ZooKeeper-derived properties to ApplicationContext PropertySources");
curator.close();
} catch (IOException e) {
logger.error("IO error attempting to load properties from ZooKeeper", e);
throw new IllegalStateException("Could not load ZooKeeper configuration");
} catch (Exception e) {
logger.error("IO error attempting to load properties from ZooKeeper", e);
throw new IllegalStateException("Could not load ZooKeeper configuration");
} finally {
if (curator != null && curator.isStarted()) {
curator.close();
}
}
}
/**
* Populate the Maven artifact name and version from a property file that
* should be on the classpath, with values entered via Maven filtering.
*
* There is a way of doing these with manifests, but it's a right faff when
* creating shaded uber-jars.
*
* #throws IOException
*/
private void populateProjectProperties() throws IOException {
logger.trace("Attempting to get project name and version from properties file");
try {
ResourcePropertySource projectProps = new ResourcePropertySource("project.properties");
this.projectName = (String) projectProps.getProperty("project.name");
this.projectVersion = (String) projectProps.getProperty("project.version");
} catch (IOException e) {
logger.error("IO error trying to find project name and version, in order to get properties from ZooKeeper");
}
}
/**
* Do the actual loading of properties.
*
* #return
* #throws Exception
* #throws IOException
*/
private Properties populatePropertiesFromZooKeeper() throws Exception, IOException {
logger.debug("Attempting to get properties from ZooKeeper");
try {
byte[] bytes = curator.getData().forPath("/distributed-config/" + projectName + "/" + projectVersion);
InputStream in = new ByteArrayInputStream(bytes);
Properties properties = new Properties();
properties.load(in);
return properties;
} catch (NoNodeException e) {
logger.error("Could not load application configuration from ZooKeeper as no node existed for project [{}]:[{}]", projectName, projectVersion);
throw e;
}
}
}

You should consider Spring Cloud Config:
http://projects.spring.io/spring-cloud/
Spring Cloud Config Centralized external configuration management
backed by a git repository. The configuration resources map directly
to Spring Environment but could be used by non-Spring applications
if desired.
Source code available here:
https://github.com/spring-cloud/spring-cloud-config
Sample application here:
https://github.com/spring-cloud/spring-cloud-config/blob/master/spring-cloud-config-sample/src/main/java/sample/Application.java

I created a set of spring beans integration zookeeper and springframework as propertyplaceholderconfigurer, in github: https://github.com/james-wu-shanghai/spring-zookeeper.git
you can take a look.

Not spring in particular but for java generally, there is a CXF implementation of the distributed OSGI standard that uses ZooKeeper as the discovery server to push updated bundles down to the container : http://cxf.apache.org/dosgi-discovery.html.

Zookeeper can be very nicely leveraged with higher abstraction using Curator APIs for configuration management in distributed applications. To get started just follow these two steps.
STEP 1 : Start zookeper server and then start zookeeper cli and create some znodes. Znodes are nothing but UNIX like files which contain values, and name of files depict property name.
To create/fetch/update properties use these commands on zookeeper cli.
create /system/dev/example/port 9091
get /system/dev/example/port
set /system/dev/example/port 9092
To fetch these properties in java program refer this code snippet.
import java.util.HashMap;
import java.util.Map;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
public class App
{
public static void main( String[] args ) throws Exception
{
final String ZK = "localhost:2181";
final Map<String, String> data = new HashMap<String, String>();
CuratorFramework client = CuratorFrameworkFactory.newClient(ZK, new ExponentialBackoffRetry(100, 3));
client.start();
System.out.println(new String(client.getData().forPath("/system/dev/example/port")));
}
}

I was at an Apache Camel talk from James Strachen last week and he mentioned using ZooKeeper under the covers for their Java-based server in the cloud as the source of configuration info.
I've seen a talk from Adrian Colyer (CTO of SpringSource) about runtime config change in Spring, but does Spring support this today?
In my opinion, if you're starting from a typically architected Spring application, I don't see you having an easy job retrofitting dynamic config changes on top of it.

After finding a suggestion to use a FactoryBean to populate a regular PropertyPlaceholderConfigurer I've built this:
package fms;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.config.AbstractFactoryBean;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.Properties;
public class ZkPropertiesFactoryBean extends AbstractFactoryBean<Properties> implements Watcher {
private Logger LOGGER = LoggerFactory.getLogger(ZkPropertiesFactoryBean.class);
private String zkConnect;
private String path;
private int timeout = 1000;
#Override protected Properties createInstance() throws Exception {
long start = System.currentTimeMillis();
Properties p = new Properties();
p.load(new ByteArrayInputStream(loadFromZk()));
double duration = (System.currentTimeMillis() - start)/1000d;
LOGGER.info(String.format("Loaded %d properties from %s:%s in %2.3f sec", p.size(), zkConnect, path, duration));
return p;
}
#Override public Class<Properties> getObjectType() {
return Properties.class;
}
private byte[] loadFromZk() throws IOException, KeeperException, InterruptedException {Stat stat = new Stat();
ZooKeeper zk = new ZooKeeper(zkConnect, timeout, this);
return zk.getData(path, false, stat);
}
#Override public void process(WatchedEvent event) {}
public void setPath(String path) {this.path = path;}
public void setZkConnect(String zkConnect) {this.zkConnect = zkConnect;}
}
In the spring-config.xml you create the beans as follows:
<bean id="zkProperties" class="fms.ZkPropertiesFactoryBean" p:zkConnect="localhost:2181" p:path="/app/zk-properties"/>
<context:property-placeholder properties-ref="zkProperties"/>

Jini/JavaSpaces discovery error

On this article: http://java.sun.com/developer/technicalArticles/tools/JavaSpaces/ is a tutorial how to run JavaSpaces client. I wrote these classes in Eclipse, started Launch-All script and Run example. It works.
After that I exported these classes into executable jar (JavaSpaceClient.jar) and tried that jar with following command:
java -jar JavaSpaceClient.jar
It works fine, gives me result:
Searching for a JavaSpace...
A JavaSpace has been discovered.
Writing a message into the space...
Reading a message from the space...
The message read is: Здраво JavaSpace свете!
My problem is when I move this jar file on my other LAN computer, it shows me error when I type same command. Here is error:
cica#cica-System-Name:~/Desktop$ java -jar JavaSpaceClient.jar
Searching for a JavaSpace...
Jul 27, 2011 11:20:54 PM net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask run
INFO: exception occurred during unicast discovery to biske-Inspiron-1525:4160 with constraints InvocationConstraints[reqs: {}, prefs: {}]
java.net.UnknownHostException: biske-Inspiron-1525
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:175)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384)
at java.net.Socket.connect(Socket.java:546)
at java.net.Socket.connect(Socket.java:495)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getSingleResponse(MultiIPDiscovery.java:134)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getResponse(MultiIPDiscovery.java:75)
at net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask.run(LookupDiscovery.java:1756)
at net.jini.discovery.LookupDiscovery$DecodeAnnouncementTask.run(LookupDiscovery.java:1599)
at com.sun.jini.thread.TaskManager$TaskThread.run(TaskManager.java:331)
I just writes "Searching for JavaSpace..." and after a while prints these error messages.
Can someone help me with this error?
EDIT:
For discovery I am using LookupDiscovery class I've found on Internet:
import java.io.IOException;
import java.rmi.RemoteException;
import net.jini.core.lookup.ServiceRegistrar;
import net.jini.core.lookup.ServiceTemplate;
import net.jini.discovery.LookupDiscovery;
import net.jini.discovery.DiscoveryListener;
import net.jini.discovery.DiscoveryEvent;
/**
A class which supports a simple JINI multicast lookup. It doesn't register
with any ServiceRegistrars it simply interrogates each one that's
discovered for a ServiceItem associated with the passed interface class.
i.e. The service needs to already have registered because we won't notice
new arrivals. [ServiceRegistrar is the interface implemented by JINI
lookup services].
#todo Be more dynamic in our lookups - see above
#author Dan Creswell (dan#dancres.org)
#version 1.00, 7/9/2003
*/
public class Lookup implements DiscoveryListener {
private ServiceTemplate theTemplate;
private LookupDiscovery theDiscoverer;
private Object theProxy;
/**
#param aServiceInterface the class of the type of service you are
looking for. Class is usually an interface class.
*/
public Lookup(Class aServiceInterface) {
Class[] myServiceTypes = new Class[] {aServiceInterface};
theTemplate = new ServiceTemplate(null, myServiceTypes, null);
}
/**
Having created a Lookup (which means it now knows what type of service
you require), invoke this method to attempt to locate a service
of that type. The result should be cast to the interface of the
service you originally specified to the constructor.
#return proxy for the service type you requested - could be an rmi
stub or an intelligent proxy.
*/
Object getService() {
synchronized(this) {
if (theDiscoverer == null) {
try {
theDiscoverer =
new LookupDiscovery(LookupDiscovery.ALL_GROUPS);
theDiscoverer.addDiscoveryListener(this);
} catch (IOException anIOE) {
System.err.println("Failed to init lookup");
anIOE.printStackTrace(System.err);
}
}
}
return waitForProxy();
}
/**
Location of a service causes the creation of some threads. Call this
method to shut those threads down either before exiting or after a
proxy has been returned from getService().
*/
void terminate() {
synchronized(this) {
if (theDiscoverer != null)
theDiscoverer.terminate();
}
}
/**
Caller of getService ends up here, blocked until we find a proxy.
#return the newly downloaded proxy
*/
private Object waitForProxy() {
synchronized(this) {
while (theProxy == null) {
try {
wait();
} catch (InterruptedException anIE) {
}
}
return theProxy;
}
}
/**
Invoked to inform a blocked client waiting in waitForProxy that
one is now available.
#param aProxy the newly downloaded proxy
*/
private void signalGotProxy(Object aProxy) {
synchronized(this) {
if (theProxy == null) {
theProxy = aProxy;
notify();
}
}
}
/**
Everytime a new ServiceRegistrar is found, we will be called back on
this interface with a reference to it. We then ask it for a service
instance of the type specified in our constructor.
*/
public void discovered(DiscoveryEvent anEvent) {
synchronized(this) {
if (theProxy != null)
return;
}
ServiceRegistrar[] myRegs = anEvent.getRegistrars();
for (int i = 0; i < myRegs.length; i++) {
ServiceRegistrar myReg = myRegs[i];
Object myProxy = null;
try {
myProxy = myReg.lookup(theTemplate);
if (myProxy != null) {
signalGotProxy(myProxy);
break;
}
} catch (RemoteException anRE) {
System.err.println("ServiceRegistrar barfed");
anRE.printStackTrace(System.err);
}
}
}
/**
When a ServiceRegistrar "disappears" due to network partition etc.
we will be advised via a call to this method - as we only care about
new ServiceRegistrars, we do nothing here.
*/
public void discarded(DiscoveryEvent anEvent) {
}
}
My client program tries simply to search for JavaSpaces service write MessageEntry into and then retrieves message and prints it out. Here is client program:
import net.jini.space.JavaSpace;
public class SpaceClient {
public static void main(String argv[]) {
try {
MessageEntry msg = new MessageEntry();
msg.content = "Hello JavaSpaces wordls!";
System.out.println("Searching for JavaSpaces...");
Lookup finder = new Lookup(JavaSpace.class);
JavaSpace space = (JavaSpace) finder.getService();
System.out.println("JavaSpaces discovered.");
System.out.println("Writing into JavaSpaces...");
space.write(msg, null, 60*60*1000);
MessageEntry template = new MessageEntry();
System.out.println("Reading message from JavaSpaces...");
MessageEntry result = (MessageEntry) space.read(template, null, Long.MAX_VALUE);
System.out.println("Message: "+result.content);
} catch(Exception e) {
e.printStackTrace();
}
}
}
And of course this is MessageEntry class:
import net.jini.core.entry.*;
public class MessageEntry implements Entry {
public String content;
public MessageEntry() {
}
public MessageEntry(String content) {
this.content = content;
}
public String toString() {
return "MessageContent: " + content;
}
}
EDIT2:
I did discovery on two Windows computers.
After that I tried Windows - Ubuntu combiantion and it doesn't work. Maybe there are some network problems? When I ping each another everything is ok. Maybe there are some DNS issues on Ubuntu..
EDIT3:
Windows - Ubuntu combination works if JavaSpaces service is started up on Windows and client program is on Ubuntu. When I try to do reverse, to run JavaSpaces service on Ubuntu and run client on Windows error occurs.
Obviously there is some problem with Ubuntu. Ubuntu has installed OpenJDK installed by default. I installed Oracle JDK, and set JAVA_HOME and put JAVA_HOME/bin into PATH variable. I wonder maybe there is some problem with different versions of Java, maybe I am not using right one.

It is possible that the service registrar that you are running (on host biske-Inspiron-1525 at port 4160), is discovering it's hostname incorrectly (without domain name) and is therefore sending out the announcements with a short hostname. Therefore, after discovering the service registrar, it is possible that subsequently the client is trying to make a connection to the service registrar it cannot resolve the hostname if it is on a different domain.
To ensure that the service registrar is running with the correct hostname, try starting it with the following command line attribute:
-Dcom.sun.jini.reggie.unicastDiscoveryHost="biske-Inspiron-1525.and.its.domain"

It appears that you are doing unicast discovery to a specific host and port and that you can't look up that host.
Assuming you can resolve the name biske-Inspiron-1525 with DNS try removing the ":4160" part and see if the unicast lookup succeeds then.
Here is an example of the code I use to look up a service. It's a bit more complicated because I implement ServiceDiscoveryListener and handle service discovery that way. I actually keep a list of services and dynamically switch between then when one fails but I stripped that part out of the example. I am also using the Configuration part of Jini which I'll explain afterwards. The service interface I am using here is called "TheService":
public class JiniClient implements ServiceDiscoveryListener {
private TheService service = null;
private Class[] serviceClasses;
private ServiceTemplate serviceTemplate;
public JiniClient(String[] configFiles) throws ConfigurationException {
Configuration config = ConfigurationProvider.getInstance(configFiles,
getClass().getClassLoader());
// Set the security manager
System.setSecurityManager(new RMISecurityManager());
// Define the service we are interested in.
serviceClasses = new Class[] {TheService.class};
serviceTemplate = new ServiceTemplate(null, serviceClasses, null);
// Build a cache of all discovered services and monitor changes
ServiceDiscoveryManager serviceMgr = null;
DiscoveryManagement mgr = null;
try {
mgr = (DiscoveryManagement)config.getEntry(
getClass().getName(), // component
"discoveryManager", // name
DiscoveryManagement.class); // type
if (null == mgr) {
throw new ConfigurationException("entry for component " +
getClass().getName() + " name " +
"discoveryManager must be non-null");
}
} catch (Exception e) {
/* This will catch both NoSuchEntryException and
* ConfigurationException. Putting them both
* below just to make that clear.
*/
if( (e instanceof NoSuchEntryException) ||
(e instanceof ConfigurationException)) {
// default value
try {
System.err.println("Warning, using default multicast discover.");
mgr = new LookupDiscoveryManager(LookupDiscovery.ALL_GROUPS,
null, // unicast locators
null); // DiscoveryListener
} catch(IOException ioe) {
e.printStackTrace();
throw new RuntimeException("Unable to create lookup discovery manager: " + e.toString());
}
}
}
try {
serviceMgr = new ServiceDiscoveryManager(mgr, new LeaseRenewalManager());
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Unable to create service discovery manager: " + e.toString());
}
try {
serviceMgr.createLookupCache(serviceTemplate,
null, // no filter
this); // listener
} catch(Exception e) {
e.printStackTrace();
throw new RuntimeException("Unable to create serviceCache: " + e.getMessage());
}
}
public void serviceAdded(ServiceDiscoveryEvent evt) {
/* Called when a service is discovered */
ServiceItem postItem = evt.getPostEventServiceItem();
//System.out.println("Service appeared: " +
// postItem.service.getClass().toString());
if(postItem.service instanceof TheService) {
/* You may be looking for multiple services.
* The serviceAdded method will be called for each
* so you can use instanceof to figure out if
* this is the one you want.
*/
service = (TheService)postItem.service;
}
}
public void serviceRemoved(ServiceDiscoveryEvent evt) {
/* This notifies you of when a service goes away.
* You could keep a list of services and then remove this
* service from the list.
*/
}
public void serviceChanged(ServiceDiscoveryEvent evt) {
/* Likewise, this is called when a service changes in some way. */
}
The Configuration system allows you to dynamically configure the discovery method so you can switch to discover specific unicast systems or multicast without changing the app. Here is an example of a unicast discovery configuration file that you could pass to the above objects constructor:
import net.jini.core.discovery.LookupLocator;
import net.jini.discovery.LookupDiscoveryManager;
import net.jini.discovery.LookupDiscovery;
com.company.JiniClient {
discoveryManager = new LookupDiscoveryManager(
LookupDiscovery.ALL_GROUPS,
new LookupLocator[] { new LookupLocator("jini://biske-Inspiron-1525.mycompany.com")},
null,
this); // the current config
}

I found solution! That was dns issue. On Ubuntu my /etc/hosts file was:
192.168.1.3 biske-Inspiron-1525 # Added by NetworkManager
127.0.0.1 localhost.localdomain localhost
::1 biske-Inspiron-1525 localhost6.localdomain6 localhost6
127.0.1.1 biske-Inspiron-1525
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
I've just removed line 127.0.1.1 biske-Inspiron-1525 and now it works fine.
Little thing was destroyed million of my nerves :)

Easy way to start a standalone JNDI server (and register some resources)

For testing purposes, I'm looking for a simple way to start a standalone JNDI server, and bind my javax.sql.DataSource to "java:/comp/env/jdbc/mydatasource" programmatically.
The server should bind itself to some URL, for example: "java.naming.provider.url=jnp://localhost:1099" (doesn't have to be JNP), so that I can look up my datasource from another process. I don't care about which JNDI server implementation I'll have to use (but I don't want to start a full-blown JavaEE server).
This should be so easy, but to my surprise, I couldn't find any (working) tutorial.

The JDK contains a JNDI provider for the RMI registry. That means you can use the RMI registry as a JNDI server. So, just start rmiregistry, set java.naming.factory.initial to com.sun.jndi.rmi.registry.RegistryContextFactory, and you're away.
The RMI registry has a flat namespace, so you won't be able to bind to java:/comp/env/jdbc/mydatasource, but you will be able to bind to something so it will accept java:/comp/env/jdbc/mydatasource, but will treat it as a single-component name (thanks, #EJP).
I've written a small application to demonstrate how to do this: https://bitbucket.org/twic/jndiserver/src
I still have no idea how the JNP server is supposed to work.

I worked on the John´s code and now is working good.
In this version I'm using libs of JBoss5.1.0.GA, see jar list below:
jboss-5.1.0.GA\client\jbossall-client.jar
jboss-5.1.0.GA\server\minimal\lib\jnpserver.jar
jboss-5.1.0.GA\server\minimal\lib\log4j.jar
jboss-remote-naming-1.0.1.Final.jar (downloaded from http://search.maven.com)
This is the new code:
import java.net.InetAddress;
import java.util.Hashtable;
import java.util.concurrent.Callable;
import javax.naming.Context;
import javax.naming.InitialContext;
import org.jnp.server.Main;
import org.jnp.server.NamingBeanImpl;
public class StandaloneJNDIServer implements Callable<Object> {
public Object call() throws Exception {
setup();
return null;
}
#SuppressWarnings("unchecked")
private void setup() throws Exception {
//configure the initial factory
//**in John´s code we did not have this**
System.setProperty(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
//start the naming info bean
final NamingBeanImpl _naming = new NamingBeanImpl();
_naming.start();
//start the jnp serve
final Main _server = new Main();
_server.setNamingInfo(_naming);
_server.setPort(5400);
_server.setBindAddress(InetAddress.getLocalHost().getHostName());
_server.start();
//configure the environment for initial context
final Hashtable _properties = new Hashtable();
_properties.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
_properties.put(Context.PROVIDER_URL, "jnp://10.10.10.200:5400");
//bind a name
final Context _context = new InitialContext(_properties);
_context.bind("jdbc", "myJDBC");
}
public static void main(String...args){
try{
new StandaloneJNDIServer().call();
}catch(Exception _e){
_e.printStackTrace();
}
}
}
To have good logging, use this log4j properties:
log4j.rootLogger=TRACE, A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
To consume the Standalone JNDI server, use this client class:
import java.util.Hashtable;
import javax.naming.Context;
import javax.naming.InitialContext;
/**
*
* #author fabiojm - Fábio José de Moraes
*
*/
public class Lookup {
public Lookup(){
}
#SuppressWarnings("unchecked")
public static void main(String[] args) {
final Hashtable _properties = new Hashtable();
_properties.put("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory");
_properties.put("java.naming.provider.url", "jnp://10.10.10.200:5400");
try{
final Context _context = new InitialContext(_properties);
System.out.println(_context);
System.out.println(_context.lookup("java:comp"));
System.out.println(_context.lookup("java:jdbc"));
}catch(Exception _e){
_e.printStackTrace();
}
}
}

Here's a code snippet adapted from JBoss remoting samples. The code that is
in the samples (version 2.5.4.SP2 ) no longer works. While the fix
is simple it took me more hours than I want to think about to figure it out.
Sigh. Anyway, maybe someone can benefit.
package org.jboss.remoting.samples.detection.jndi.custom;
import java.net.InetAddress;
import java.util.concurrent.Callable;
import org.jnp.server.Main;
import org.jnp.server.NamingBeanImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class StandaloneJNDIServer implements Callable<Object> {
private static Logger logger = LoggerFactory.getLogger( StandaloneJNDIServer.class );
// Default locator values - command line args can override transport and port
private static String transport = "socket";
private static String host = "localhost";
private static int port = 5400;
private int detectorPort = 5400;
public StandaloneJNDIServer() {}
#Override
public Object call() throws Exception {
StandaloneJNDIServer.println("Starting JNDI server... to stop this server, kill it manually via Control-C");
//StandaloneJNDIServer server = new StandaloneJNDIServer();
try {
this.setupJNDIServer();
// wait forever, let the user kill us at any point (at which point, the client will detect we went down)
while(true) {
Thread.sleep(1000);
}
}
catch(Exception e) {
e.printStackTrace();
}
StandaloneJNDIServer.println("Stopping JBoss/Remoting server");
return null;
}
private void setupJNDIServer() throws Exception
{
// start JNDI server
String detectorHost = InetAddress.getLocalHost().getHostName();
Main JNDIServer = new Main();
// Next two lines add a naming implemention into
// the server object that handles requests. Without this you get a nice NPE.
NamingBeanImpl namingInfo = new NamingBeanImpl();
namingInfo.start();
JNDIServer.setNamingInfo( namingInfo );
JNDIServer.setPort( detectorPort );
JNDIServer.setBindAddress(detectorHost);
JNDIServer.start();
System.out.println("Started JNDI server on " + detectorHost + ":" + detectorPort );
}
/**
* Outputs a message to stdout.
*
* #param msg the message to output
*/
public static void println(String msg)
{
System.out.println(new java.util.Date() + ": [SERVER]: " + msg);
}
}

I know I'm late to the party, but I ended up hacking this together like so
InitialContext ctx = new InitialContext();
// check if we have a JNDI binding for "jdbc". If we do not, we are
// running locally (i.e. through JUnit, etc)
boolean isJndiBound = true;
try {
ctx.lookup("jdbc");
} catch(NameNotFoundException ex) {
isJndiBound = false;
}
if(!isJndiBound) {
// Create the "jdbc" sub-context (i.e. the directory)
ctx.createSubcontext("jdbc");
//parse the jetty-web.xml file
Map<String, DataSource> dataSourceProperties = JettyWebParser.parse();
//add the data sources to the sub-context
for(String key : dataSourceProperties.keySet()) {
DataSource ds = dataSourceProperties.get(key);
ctx.bind(key, ds);
}
}

Have you considered using Mocks? If I recall correctly you use Interfaces to interact with JNDI. I know I've mocked them out at least once before.
As a fallback, you could probably use Tomcat. It's not a full blown J2EE impl, it starts fast, and is fairly easy to configure JNDI resources for. DataSource setup is well documented. It's sub-optimal, but should work.

You imply you've found non-working tutorials; that may mean you've already seen these:
J2EE or J2SE? JNDI works with both
Standalone JNDI server using jnpserver.jar
I had a quick go, but couldn't get this working. A little more perseverance might do it, though.

For local, one process standalone jar purpouses I would use spring-test package:
SimpleNamingContextBuilder builder = new SimpleNamingContextBuilder();
SQLServerConnectionPoolDataSource myDS = new SQLServerConnectionPoolDataSource();
//setup...
builder.bind("java:comp/env/jdbc/myDS", myDS);
builder.activate();
startup log:
22:33:41.607 [main] INFO org.springframework.mock.jndi.SimpleNamingContextBuilder - Static JNDI binding: [java:comp/env/jdbc/myDS] = [SQLServerConnectionPoolDataSource:1]
22:33:41.615 [main] INFO org.springframework.mock.jndi.SimpleNamingContextBuilder - Activating simple JNDI environment

I have been looking for a similar simple starter solution recently. The "file system service provider from Sun Microsystems" has worked for me well. See https://docs.oracle.com/javase/jndi/tutorial/basics/prepare/initial.html.
The problem with the RMI registry is that you need a viewer - here you just need to look at file contents.
You may need fscontext-4.2.jar - I obtained it from http://www.java2s.com/Code/Jar/f/Downloadfscontext42jar.htm

Simple Remote Shared Object with Red5 Flash Server

I am trying to create a simple chat client using the red5 media server, but I seem to be having a slight hiccup. I am creating a shared object on the server side, and it seems to be creating it successfully. However, when I make changes to the object via the client (type a message), the SYNC event fires, but the content within the shared object remains empty. I suspect I am doing something wrong on the java end, any advice?
Console Results:
Success!
Server Message: clear
Server Message: [object Object]
Local message: asdf
Server Message: change
Server Message: [object Object]
Local message: fdsa
Server Message: change
Server Message: [object Object]
Local message: fewa
Server Message: change
Server Message: [object Object]
Server Side:
package org.red5.core;
import java.util.List;
import org.red5.server.adapter.ApplicationAdapter;
import org.red5.server.api.IConnection;
import org.red5.server.api.IScope;
import org.red5.server.api.service.ServiceUtils;
import org.red5.server.api.so.ISharedObject;
// import org.apache.commons.logging.Log;
// import org.apache.commons.logging.LogFactory;
public class Application extends ApplicationAdapter {
private IScope appScope;
// private static final Log log = LogFactory.getLog( Application.class );
/** {#inheritDoc} */
#Override
public boolean connect(IConnection conn, IScope scope, Object[] params) {
appScope = scope;
createSharedObject(appScope, "generalChat", false); // Creates general chat shared object
return true;
}
/** {#inheritDoc} */
#Override
public void disconnect(IConnection conn, IScope scope) {
super.disconnect(conn, scope);
}
public void updateChat(Object[] params)
{
ISharedObject so = getSharedObject(appScope, "generalChat"); // Declares and stores general chat data in general chat shared object
so.setAttribute("point", params[0].toString());
}
}
Client Side:
package
{
import flash.display.MovieClip;
import flash.events.*;
import flash.net.*;
// This class is going to handle all data to and from from media server
public class SOConnect extends MovieClip
{
// Variables
var nc:NetConnection = null;
var so:SharedObject;
public function SOConnect():void
{
}
public function connect():void
{
// Create a NetConnection and connect to red5
nc = new NetConnection();
nc.addEventListener(NetStatusEvent.NET_STATUS, netStatusHandler);
nc.connect("rtmp://localhost/testChat");
// Create a StoredObject for general chat
so = SharedObject.getRemote("generalChat", nc.uri, false);
so.connect(nc);
so.addEventListener(SyncEvent.SYNC, receiveChat)
}
public function sendChat(msg:String)
{
trace ("Local message: " + msg);
nc.call("updateChat", null, msg)
}
public function receiveChat(e:SyncEvent):void
{
for (var i in e.changeList)
{
trace ("Server Message: " + e.changeList[i].code)
trace ("Server Message: " + e.changeList[i])
}
}
// Given result, determine successful connection
private function netStatusHandler(e:NetStatusEvent):void
{
if (e.info.code == "NetConnection.Connect.Success")
{
trace("Success!");
}
else
{
trace("Failure!\n");
trace(e.info.code);
}
}
}
}

you don't need to write anything on the server side in order to do a chat in as3 and red5;
here is an example for you the chat that it is working and it is written in as3/flex3

Yes its posible to create a chat without writing server side code but i dont see how someone could control users disconnections or use lists of users on sync, anyway back to the subject maybe you have a problem with dir permissions so try running red5 as root/admin once , just to check if it works, if it does you should create a user (with the correct writing permissions) in your system and then run red5 using that user.