| /* nContext.java -- implementation of NamingContext |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.CORBA.NamingService; |
| |
| import org.omg.CORBA.Object; |
| import org.omg.CosNaming.Binding; |
| import org.omg.CosNaming.BindingIteratorHolder; |
| import org.omg.CosNaming.BindingListHolder; |
| import org.omg.CosNaming.BindingType; |
| import org.omg.CosNaming.NameComponent; |
| import org.omg.CosNaming.NamingContext; |
| import org.omg.CosNaming.NamingContextOperations; |
| import org.omg.CosNaming.NamingContextPackage.AlreadyBound; |
| import org.omg.CosNaming.NamingContextPackage.CannotProceed; |
| import org.omg.CosNaming.NamingContextPackage.InvalidName; |
| import org.omg.CosNaming.NamingContextPackage.NotEmpty; |
| import org.omg.CosNaming.NamingContextPackage.NotFound; |
| import org.omg.CosNaming.NamingContextPackage.NotFoundReason; |
| import org.omg.CosNaming._NamingContextImplBase; |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * This class implements the transient naming service, defined by |
| * {@link NamingContext}. The 'transient' means that the service does |
| * not store its state into the persistent memory. If the service is |
| * restarted, the named objects must be re-registered again. |
| * |
| * TODO Write the persistent naming service. |
| * |
| * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) |
| */ |
| public class TransientContext |
| extends _NamingContextImplBase |
| implements NamingContext, NamingContextOperations |
| { |
| /** |
| * Use serial version UID for interoperability. |
| */ |
| private static final long serialVersionUID = 2; |
| |
| /** |
| * The already named contexts. |
| */ |
| protected final NamingMap named_contexts; |
| |
| /** |
| * The already named objects. |
| */ |
| protected final NamingMap named_objects; |
| |
| /** |
| * Create the naming conetxt with default (transient) naming maps. |
| */ |
| public TransientContext() |
| { |
| this(new NamingMap(), new NamingMap()); |
| } |
| |
| /** |
| * Create the naming conetxt with the two provided naming maps. |
| * |
| * @param context_map the map for contexts |
| * @param object_map the map for objectss |
| */ |
| public TransientContext(NamingMap context_map, NamingMap object_map) |
| { |
| named_contexts = context_map; |
| named_objects = object_map; |
| } |
| |
| /** |
| * Gives the object a name, valid in this context. |
| * |
| * @param a_name the name, being given to the object. |
| * @param an_object the object, being named. |
| * |
| * @throws AlreadyBound if the object is already named in this context. |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public void bind(NameComponent[] a_name, Object an_object) |
| throws NotFound, CannotProceed, InvalidName, AlreadyBound |
| { |
| if (a_name.length == 1) |
| named_objects.bind(a_name [ 0 ], an_object); |
| else |
| { |
| NamingContext context = |
| (NamingContext) named_contexts.get(a_name [ 0 ]); |
| context.bind(getSuffix(a_name), an_object); |
| } |
| } |
| |
| /** |
| * Gives a child context name, valid in this context. |
| * |
| * @param a_name the name, being given to the child context. |
| * @param a_context the child context being named. |
| * |
| * @throws AlreadyBound if the child context is already named in |
| * the current context. |
| */ |
| public void bind_context(NameComponent[] a_name, NamingContext a_context) |
| throws NotFound, CannotProceed, InvalidName, AlreadyBound |
| { |
| if (a_name.length == 1) |
| named_contexts.bind(a_name [ 0 ], a_context); |
| else |
| { |
| NamingContext context = |
| (NamingContext) named_contexts.get(a_name [ 0 ]); |
| context.bind_context(getSuffix(a_name), a_context); |
| } |
| } |
| |
| /** |
| * Create a new context and give it a given name (bound it) |
| * in the current context. |
| * |
| * The context being created is returned by calling |
| * {@link #new_context()}. |
| * |
| * @param a_name the name being given to the new context. |
| * |
| * @return the newly created context. |
| * |
| * @throws AlreadyBound if the name is already in use. |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public NamingContext bind_new_context(NameComponent[] a_name) |
| throws NotFound, AlreadyBound, CannotProceed, |
| InvalidName |
| { |
| if (named_contexts.containsKey(a_name [ 0 ]) || |
| named_objects.containsKey(a_name [ 0 ]) |
| ) |
| throw new AlreadyBound(); |
| |
| NamingContext child = new_context(); |
| bind_context(a_name, child); |
| return child; |
| } |
| |
| /** |
| * Destroy this context (must be empty). |
| * @throws NotEmpty if the context being destroyed is not empty. |
| */ |
| public void destroy() |
| throws NotEmpty |
| { |
| if (named_contexts.size() > 0 || named_objects.size() > 0) |
| throw new NotEmpty(); |
| } |
| |
| /** |
| * Iterate over all bindings, defined in this namind context. |
| * |
| * @param amount the maximal number of context to return in the |
| * holder a_list. The remaining bindings are accessible via iterator |
| * an_iter. If the parameter amount is zero, all bindings are accessed only |
| * via this iterator. |
| * |
| * This implementation list contexts first, then objects. |
| * |
| * @param a_list the holder, where the returned bindigs are stored. |
| * @param an_iter the iterator that can be used to access the remaining |
| * bindings. |
| */ |
| public void list(int amount, BindingListHolder a_list, |
| BindingIteratorHolder an_iter |
| ) |
| { |
| int nb = named_contexts.size() + named_objects.size(); |
| int nl = nb; |
| if (nl > amount) |
| nl = amount; |
| |
| a_list.value = new Binding[ nl ]; |
| |
| Iterator contexts = named_contexts.entries().iterator(); |
| Iterator objects = named_objects.entries().iterator(); |
| |
| // Create a binding list. |
| for (int i = 0; i < nl; i++) |
| { |
| if (contexts.hasNext()) |
| a_list.value [ i ] = mkBinding(contexts.next(), BindingType.ncontext); |
| else if (objects.hasNext()) |
| a_list.value [ i ] = mkBinding(objects.next(), BindingType.nobject); |
| else |
| throw new InternalError(); |
| } |
| |
| // Create an iterator. |
| Binding[] remainder = new Binding[ nb - nl ]; |
| int p = 0; |
| |
| while (contexts.hasNext()) |
| remainder [ p++ ] = mkBinding(contexts.next(), BindingType.ncontext); |
| |
| while (objects.hasNext()) |
| remainder [ p++ ] = mkBinding(objects.next(), BindingType.nobject); |
| |
| Binding_iterator_impl bit = new Binding_iterator_impl(remainder); |
| _orb().connect(bit); |
| an_iter.value = bit; |
| } |
| |
| /** |
| * Creates a new naming context, not bound to any name. |
| */ |
| public NamingContext new_context() |
| { |
| Ext context = new Ext(new TransientContext()); |
| |
| // Connect the context to the current ORB: |
| _orb().connect(context); |
| return context; |
| } |
| |
| /** |
| * Names or renames the object. |
| * |
| * @param a_name the new name, being given to the object |
| * in the scope of the current context. If the object is already |
| * named in this context, it is renamed. |
| * |
| * @param an_object the object, being named. |
| * |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public void rebind(NameComponent[] a_name, Object an_object) |
| throws NotFound, CannotProceed, InvalidName |
| { |
| if (a_name.length == 1) |
| named_objects.rebind(a_name [ 0 ], an_object); |
| else |
| { |
| NamingContext context = |
| (NamingContext) named_contexts.get(a_name [ 0 ]); |
| context.rebind(getSuffix(a_name), an_object); |
| } |
| } |
| |
| /** |
| * Names or renames the child context. |
| * If the child context is already named in |
| * the current context, it is renamed. The the name being given is in |
| * use, the old meaning of the name is discarded. |
| * |
| * @param a_name the name, being given to the child context in the scope |
| * of the current context. |
| * |
| * @param a_context the child context being named. |
| * |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public void rebind_context(NameComponent[] a_name, NamingContext a_context) |
| throws NotFound, CannotProceed, InvalidName |
| { |
| if (a_name.length == 1) |
| named_contexts.rebind(a_name [ 0 ], a_context); |
| else |
| { |
| NamingContext context = |
| (NamingContext) named_contexts.get(a_name [ 0 ]); |
| context.rebind_context(getSuffix(a_name), a_context); |
| } |
| } |
| |
| /** |
| * Get the object, bound to the specified name in this |
| * context. The given object must match the bound |
| * name. |
| * |
| * This implementation resolves the names as defined in specification |
| * of the CORBA naming service. This means, if the beginning of the |
| * name can be resolved to some naming context, the request is |
| * forwarded to this context, passing the unresolved name part as a |
| * parameter. In this way, it is possible to have a hierarchy of the |
| * naming services. The central services resolve the the beginning |
| * of the name. The local services resolve the remaining nodes of the |
| * name that may be relevant to some local details. It can be three or |
| * more ranks of the naming services. |
| * |
| * @param a_name the object name. |
| * |
| * @return the object, matching this name. The client |
| * usually casts or narrows (using the helper) the returned value |
| * to the more specific type. |
| * |
| * @throws NotFound if the name cannot be resolved. |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public Object resolve(NameComponent[] a_name) |
| throws NotFound, CannotProceed, InvalidName |
| { |
| NameValidator.check(a_name); |
| |
| if (a_name.length > 1) |
| return resolveSubContext(a_name); |
| else |
| { |
| // A single node name. |
| org.omg.CORBA.Object object; |
| |
| object = named_objects.get(a_name [ 0 ]); |
| if (object != null) |
| return object; |
| |
| object = named_contexts.get(a_name [ 0 ]); |
| if (object != null) |
| return object; |
| } |
| |
| throw new NotFound(NotFoundReason.missing_node, a_name); |
| } |
| |
| /** |
| * Removes the name from the binding context. |
| * |
| * @param a_name a name to remove. |
| * |
| * @throws InvalidName if the name has zero length or otherwise invalid. |
| */ |
| public void unbind(NameComponent[] a_name) |
| throws NotFound, CannotProceed, InvalidName |
| { |
| NameValidator.check(a_name); |
| |
| // Single node name - handle it. |
| if (a_name.length == 1) |
| { |
| if (named_objects.containsKey(a_name [ 0 ])) |
| named_objects.remove(a_name [ 0 ]); |
| else if (named_contexts.containsKey(a_name [ 0 ])) |
| named_contexts.remove(a_name [ 0 ]); |
| else |
| throw new NotFound(NotFoundReason.missing_node, a_name); |
| } |
| else |
| { |
| // Handle the first node and forward the command. |
| NamingContext subcontext = |
| (NamingContext) named_contexts.get(a_name [ 0 ]); |
| |
| if (subcontext == null) |
| throw new NotFound(NotFoundReason.missing_node, a_name); |
| |
| subcontext.unbind(getSuffix(a_name)); |
| } |
| } |
| |
| /** |
| * Get the name suffix, discarding the first member. |
| */ |
| private NameComponent[] getSuffix(NameComponent[] a_name) |
| { |
| NameComponent[] suffix = new NameComponent[ a_name.length - 1 ]; |
| System.arraycopy(a_name, 1, suffix, 0, suffix.length); |
| return suffix; |
| } |
| |
| /** |
| * Create a binding. |
| * |
| * @param an_entry the entry, defining the bound object. |
| * @param type the binding type. |
| * @return the created binding. |
| */ |
| private Binding mkBinding(java.lang.Object an_entry, BindingType type) |
| { |
| Map.Entry entry = (Map.Entry) an_entry; |
| Binding b = new Binding(); |
| |
| // The name component has always only one node (the current context) |
| b.binding_name = new NameComponent[] { (NameComponent) entry.getKey() }; |
| b.binding_type = type; |
| return b; |
| } |
| |
| /** |
| * Find the context, bound to the first name of the given |
| * name, and pass the remainder (without the first node) |
| * of the name for that context to resolve. |
| * |
| * @param a_name the name to resolve. |
| * |
| * @return the resolved context |
| */ |
| private Object resolveSubContext(NameComponent[] a_name) |
| throws NotFound, CannotProceed, InvalidName |
| { |
| // A multiple node name. |
| // This context resolves the first node only. |
| NamingContext context = (NamingContext) named_contexts.get(a_name [ 0 ]); |
| if (context == null) |
| throw new NotFound(NotFoundReason.missing_node, a_name); |
| |
| NameComponent[] suffix = getSuffix(a_name); |
| |
| return context.resolve(suffix); |
| } |
| } |