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Apache OODT Common Utilities Project
// Licensed to the Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE.txt file distributed with this work for
// additional information regarding copyright ownership. The ASF licenses this
// file to you under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
package org.apache.oodt.commons.object.jndi;
import java.rmi.AlreadyBoundException;
import java.rmi.NotBoundException;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.Arrays;
import java.util.Collections;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import javax.naming.CommunicationException;
import javax.naming.CompositeName;
import javax.naming.Context;
import javax.naming.InvalidNameException;
import javax.naming.Name;
import javax.naming.NameAlreadyBoundException;
import javax.naming.NameClassPair;
import javax.naming.NameNotFoundException;
import javax.naming.NameParser;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.NotContextException;
import javax.naming.OperationNotSupportedException;
/**
* Context for binding and looking up distributed objects in RMI.
*
* @author Kelly
* @version $Revision: 1.1 $
*/
public class RMIContext implements Context {
/*
* Construct the RMI object context.
*
* @param host Host name.
* @param port Port number.
*/
public RMIContext(String host, int port) {
Hashtable environment = new Hashtable();
environment.put("host", host);
environment.put("port", port);
initEnv(environment);
}
/**
* Construct the RMI object context.
*
* @param environment Its environment, currently unused.
*/
public RMIContext(Hashtable environment) {
initEnv(environment);
}
/* Initializes environment
*
* @param environment Its environment, currently unused.
*/
private void initEnv(Hashtable environment) {
if (environment == null) {
throw new IllegalArgumentException("Nonnull environment required");
}
this.environment = (Hashtable) environment.clone();
}
public Object lookup(String name) throws NamingException {
checkName(name);
name = toRMIName(name);
if (name.length() == 0) {
return new RMIContext(environment);
}
Registry registry = getRegistry();
try {
return registry.lookup(name);
} catch (NotBoundException ex) {
throw new NameNotFoundException(name + " not found in RMI registry " + registry);
} catch (RemoteException ex) {
throw new NamingException("Remote exception: " + ex.getMessage());
}
}
public Object lookup(Name name) throws NamingException {
return lookup(name.toString());
}
public void bind(String name, Object obj) throws NamingException {
checkName(name);
Registry registry = getRegistry();
try {
registry.bind(toRMIName(name), (Remote) obj);
} catch (AlreadyBoundException ex) {
throw new NameAlreadyBoundException(name + " already bound in RMI registry " + registry);
} catch (RemoteException ex) {
throw new NamingException("Remote exception: " + ex.getMessage());
}
}
public void bind(Name name, Object obj) throws NamingException {
bind(name.toString(), obj);
}
public void rebind(String name, Object obj) throws NamingException {
checkName(name);
try {
Registry registry = getRegistry();
registry.rebind(toRMIName(name), (Remote) obj);
} catch (RemoteException ex) {
ex.printStackTrace();
throw new NamingException("Remote exception: " + ex.getMessage());
}
}
public void rebind(Name name, Object obj) throws NamingException {
rebind(name.toString(), obj);
}
public void unbind(String name) throws NamingException {
checkName(name);
Registry registry = getRegistry();
try {
registry.unbind(toRMIName(name));
} catch (NotBoundException ex) {
throw new NameNotFoundException(name + " not found in RMI registry " + registry);
} catch (RemoteException ex) {
throw new NamingException("Remote exception: " + ex.getMessage());
}
}
public void unbind(Name name) throws NamingException {
unbind(name.toString());
}
public void rename(String oldName, String newName) throws NamingException {
checkName(newName);
throw new OperationNotSupportedException("Not yet implemented");
}
public void rename(Name oldName, Name newName) throws NamingException {
rename(oldName.toString(), newName.toString());
}
public NamingEnumeration list(String name) throws NamingException {
if (name.length() > 0) {
throw new NotContextException("Subcontexts not supported");
}
final Iterator i = getCurrentBindings().iterator();
return new NamingEnumeration() {
public void close() {}
public boolean hasMore() {
return i.hasNext();
}
public Object next() throws NamingException {
String n = "urn:eda:rmi:" + (String) i.next();
org.apache.oodt.commons.Service server = (org.apache.oodt.commons.Service) lookup(n);
try {
return new NameClassPair(n, server.getServerInterfaceName());
} catch (RemoteException ex) {
throw new CommunicationException(ex.getMessage());
}
}
public boolean hasMoreElements() {
return hasMore();
}
public Object nextElement() {
Object next = null;
try {
next = next();
} catch (RuntimeException ex) {
throw ex;
} catch (Exception ignore) {}
return next;
}
};
}
public NamingEnumeration list(Name name) throws NamingException {
return list(name.toString());
}
public NamingEnumeration listBindings(String name) throws NamingException {
if (name.length() > 0) {
throw new NotContextException("Subcontexts not supported");
}
final Iterator i = getCurrentBindings().iterator();
return new NamingEnumeration() {
public void close() {}
public boolean hasMore() {
return i.hasNext();
}
public Object next() throws NamingException {
String n = "urn:eda:rmi:" + (String) i.next();
return new javax.naming.Binding(n, lookup(n));
}
public boolean hasMoreElements() {
return hasMore();
}
public Object nextElement() {
Object next = null;
try {
next = next();
} catch (RuntimeException ex) {
throw ex;
} catch (Exception ignore) {}
return next;
}
};
}
public NamingEnumeration listBindings(Name name) throws NamingException {
return listBindings(name.toString());
}
public void destroySubcontext(String name) throws NamingException {
throw new OperationNotSupportedException("Not yet implemented");
}
public void destroySubcontext(Name name) throws NamingException {
destroySubcontext(name.toString());
}
public Context createSubcontext(String name) throws NamingException {
throw new OperationNotSupportedException("Subcontexts not supported");
}
public Context createSubcontext(Name name) throws NamingException {
return createSubcontext(name.toString());
}
public Object lookupLink(String name) throws NamingException {
return lookup(name);
}
public Object lookupLink(Name name) throws NamingException {
return lookupLink(name.toString());
}
public NameParser getNameParser(String name) throws NamingException {
return nameParser;
}
public NameParser getNameParser(Name name) throws NamingException {
return getNameParser(name.toString());
}
public String composeName(String name, String prefix) throws NamingException {
Name result = composeName(new CompositeName(name), new CompositeName(prefix));
return result.toString();
}
public Name composeName(Name name, Name prefix) throws NamingException {
Name result = (Name) prefix.clone();
result.addAll(name);
return result;
}
public Object addToEnvironment(String propName, Object propVal) throws NamingException {
if (environment == null) {
environment = new Hashtable();
}
return environment.put(propName, propVal);
}
public Object removeFromEnvironment(String propName) throws NamingException {
if (environment == null) {
return null;
}
return environment.remove(propName);
}
public Hashtable getEnvironment() throws NamingException {
if (environment == null) {
return new Hashtable();
}
return (Hashtable) environment.clone();
}
public String getNameInNamespace() throws NamingException {
return "";
}
public void close() throws NamingException {
environment = null;
}
/**
* Get the current bindings in the RMI registry.
*
* @return A list of the current bindings, as simple string names.
*/
private List getCurrentBindings() throws NamingException {
List names;
try {
Registry registry = getRegistry();
names = Arrays.asList(registry.list());
} catch (RemoteException ex) {
names = Collections.EMPTY_LIST;
}
return names;
}
/**
* Convert the context object name into an rmiregistry name.
*
* @param name Context name.
* @return rmiregistry name.
*/
private String toRMIName(String name) {
if (name == null) {
return "";
}
if (name.startsWith("urn:eda:rmi:")) {
return name.substring(12);
}
if (name.startsWith("rmi:")) {
return name.substring(4);
}
return name;
}
/**
* Get the RMI registry.
*
* @return a Registry value.
* @throws NamingException if an error occurs.
*/
private Registry getRegistry() throws NamingException {
if (registry != null) {
return registry;
}
try {
String host = environment.containsKey("host")? (String) environment.get("host") : "localhost";
int port = environment.containsKey("port")? (Integer) environment.get("port")
: Registry.REGISTRY_PORT;
registry = LocateRegistry.getRegistry(host, port);
} catch (RemoteException ex) {
throw new NamingException("Remote exception locating registry: " + ex.getMessage());
}
return registry;
}
/**
* Ensure the name is an RMI object context name.
*
* RMI object context names are URNs in the eda namespace, in the
* rmi subnamespace.
*
* @param name Name to check.
* @throws InvalidNameException If name's not an RMI object context name.
*/
private void checkName(String name) throws InvalidNameException {
if (name == null) {
throw new IllegalArgumentException("Can't check a null name");
}
if (name.length() == 0) {
throw new InvalidNameException("Name's length is zero");
}
if (!name.startsWith("urn:eda:rmi:")) {
throw new InvalidNameException("Not an RMI name; try urn:eda:rmi:yadda-yadda");
}
}
/** Context's environment; currently unused. */
private Hashtable environment;
/** RMI Registry. */
private Registry registry;
/** Parser for object names. */
private static final NameParser nameParser = new ObjectNameParser();
}