Java tutorial
/* * $Header: /home/cvs/jakarta-tomcat-catalina/catalina/src/share/org/apache/naming/NamingContext.java,v 1.2 2003/05/29 16:19:53 remm Exp $ * $Revision: 1.2 $ * $Date: 2003/05/29 16:19:53 $ * * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * * [Additional notices, if required by prior licensing conditions] * */ package org.apache.naming; import java.util.Hashtable; import java.util.Enumeration; import javax.naming.Context; import javax.naming.Name; import javax.naming.LinkRef; import javax.naming.CompositeName; import javax.naming.NameParser; import javax.naming.Referenceable; import javax.naming.Reference; import javax.naming.NamingEnumeration; import javax.naming.NamingException; import javax.naming.NameNotFoundException; import javax.naming.NotContextException; import javax.naming.InitialContext; import javax.naming.OperationNotSupportedException; import javax.naming.spi.NamingManager; /** * Catalina JNDI Context implementation. * * @author Remy Maucherat * @version $Revision: 1.2 $ $Date: 2003/05/29 16:19:53 $ */ public class NamingContext implements Context { // -------------------------------------------------------------- Constants /** * Name parser for this context. */ protected static final NameParser nameParser = new NameParserImpl(); private static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory .getLog(NamingContext.class); // ----------------------------------------------------------- Constructors /** * Builds a naming context using the given environment. */ public NamingContext(Hashtable env, String name) throws NamingException { this.bindings = new Hashtable(); this.env = new Hashtable(); // FIXME ? Could be put in the environment ? this.name = name; // Populating the environment hashtable if (env != null) { Enumeration envEntries = env.keys(); while (envEntries.hasMoreElements()) { String entryName = (String) envEntries.nextElement(); addToEnvironment(entryName, env.get(entryName)); } } } /** * Builds a naming context using the given environment. */ public NamingContext(Hashtable env, String name, Hashtable bindings) throws NamingException { this(env, name); this.bindings = bindings; } // ----------------------------------------------------- Instance Variables /** * Environment. */ protected Hashtable env; /** * The string manager for this package. */ protected StringManager sm = StringManager.getManager(Constants.Package); /** * Bindings in this Context. */ protected Hashtable bindings; /** * Name of the associated Catalina Context. */ protected String name; // --------------------------------------------------------- Public Methods // -------------------------------------------------------- Context Methods /** * Retrieves the named object. If name is empty, returns a new instance * of this context (which represents the same naming context as this * context, but its environment may be modified independently and it may * be accessed concurrently). * * @param name the name of the object to look up * @return the object bound to name * @exception NamingException if a naming exception is encountered */ public Object lookup(Name name) throws NamingException { return lookup(name, true); } /** * Retrieves the named object. * * @param name the name of the object to look up * @return the object bound to name * @exception NamingException if a naming exception is encountered */ public Object lookup(String name) throws NamingException { return lookup(new CompositeName(name), true); } /** * Binds a name to an object. All intermediate contexts and the target * context (that named by all but terminal atomic component of the name) * must already exist. * * @param name the name to bind; may not be empty * @param obj the object to bind; possibly null * @exception NameAlreadyBoundException if name is already bound * @exception InvalidAttributesException if object did not supply all * mandatory attributes * @exception NamingException if a naming exception is encountered */ public void bind(Name name, Object obj) throws NamingException { bind(name, obj, false); } /** * Binds a name to an object. * * @param name the name to bind; may not be empty * @param obj the object to bind; possibly null * @exception NameAlreadyBoundException if name is already bound * @exception InvalidAttributesException if object did not supply all * mandatory attributes * @exception NamingException if a naming exception is encountered */ public void bind(String name, Object obj) throws NamingException { bind(new CompositeName(name), obj); } /** * Binds a name to an object, overwriting any existing binding. All * intermediate contexts and the target context (that named by all but * terminal atomic component of the name) must already exist. * <p> * If the object is a DirContext, any existing attributes associated with * the name are replaced with those of the object. Otherwise, any * existing attributes associated with the name remain unchanged. * * @param name the name to bind; may not be empty * @param obj the object to bind; possibly null * @exception InvalidAttributesException if object did not supply all * mandatory attributes * @exception NamingException if a naming exception is encountered */ public void rebind(Name name, Object obj) throws NamingException { bind(name, obj, true); } /** * Binds a name to an object, overwriting any existing binding. * * @param name the name to bind; may not be empty * @param obj the object to bind; possibly null * @exception InvalidAttributesException if object did not supply all * mandatory attributes * @exception NamingException if a naming exception is encountered */ public void rebind(String name, Object obj) throws NamingException { rebind(new CompositeName(name), obj); } /** * Unbinds the named object. Removes the terminal atomic name in name * from the target context--that named by all but the terminal atomic * part of name. * <p> * This method is idempotent. It succeeds even if the terminal atomic * name is not bound in the target context, but throws * NameNotFoundException if any of the intermediate contexts do not exist. * * @param name the name to bind; may not be empty * @exception NameNotFoundException if an intermediate context does not * exist * @exception NamingException if a naming exception is encountered */ public void unbind(Name name) throws NamingException { checkWritable(); while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) throw new NamingException(sm.getString("namingContext.invalidName")); NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (name.size() > 1) { if (entry.type == NamingEntry.CONTEXT) { ((Context) entry.value).unbind(name.getSuffix(1)); } else { throw new NamingException(sm.getString("namingContext.contextExpected")); } } else { bindings.remove(name.get(0)); } } /** * Unbinds the named object. * * @param name the name to bind; may not be empty * @exception NameNotFoundException if an intermediate context does not * exist * @exception NamingException if a naming exception is encountered */ public void unbind(String name) throws NamingException { unbind(new CompositeName(name)); } /** * Binds a new name to the object bound to an old name, and unbinds the * old name. Both names are relative to this context. Any attributes * associated with the old name become associated with the new name. * Intermediate contexts of the old name are not changed. * * @param oldName the name of the existing binding; may not be empty * @param newName the name of the new binding; may not be empty * @exception NameAlreadyBoundException if newName is already bound * @exception NamingException if a naming exception is encountered */ public void rename(Name oldName, Name newName) throws NamingException { Object value = lookup(oldName); bind(newName, value); unbind(oldName); } /** * Binds a new name to the object bound to an old name, and unbinds the * old name. * * @param oldName the name of the existing binding; may not be empty * @param newName the name of the new binding; may not be empty * @exception NameAlreadyBoundException if newName is already bound * @exception NamingException if a naming exception is encountered */ public void rename(String oldName, String newName) throws NamingException { rename(new CompositeName(oldName), new CompositeName(newName)); } /** * Enumerates the names bound in the named context, along with the class * names of objects bound to them. The contents of any subcontexts are * not included. * <p> * If a binding is added to or removed from this context, its effect on * an enumeration previously returned is undefined. * * @param name the name of the context to list * @return an enumeration of the names and class names of the bindings in * this context. Each element of the enumeration is of type NameClassPair. * @exception NamingException if a naming exception is encountered */ public NamingEnumeration list(Name name) throws NamingException { // Removing empty parts while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) { return new NamingContextEnumeration(bindings.elements()); } NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (entry.type != NamingEntry.CONTEXT) { throw new NamingException(sm.getString("namingContext.contextExpected")); } return ((Context) entry.value).list(name.getSuffix(1)); } /** * Enumerates the names bound in the named context, along with the class * names of objects bound to them. * * @param name the name of the context to list * @return an enumeration of the names and class names of the bindings in * this context. Each element of the enumeration is of type NameClassPair. * @exception NamingException if a naming exception is encountered */ public NamingEnumeration list(String name) throws NamingException { return list(new CompositeName(name)); } /** * Enumerates the names bound in the named context, along with the * objects bound to them. The contents of any subcontexts are not * included. * <p> * If a binding is added to or removed from this context, its effect on * an enumeration previously returned is undefined. * * @param name the name of the context to list * @return an enumeration of the bindings in this context. * Each element of the enumeration is of type Binding. * @exception NamingException if a naming exception is encountered */ public NamingEnumeration listBindings(Name name) throws NamingException { // Removing empty parts while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) { return new NamingContextBindingsEnumeration(bindings.elements()); } NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (entry.type != NamingEntry.CONTEXT) { throw new NamingException(sm.getString("namingContext.contextExpected")); } return ((Context) entry.value).listBindings(name.getSuffix(1)); } /** * Enumerates the names bound in the named context, along with the * objects bound to them. * * @param name the name of the context to list * @return an enumeration of the bindings in this context. * Each element of the enumeration is of type Binding. * @exception NamingException if a naming exception is encountered */ public NamingEnumeration listBindings(String name) throws NamingException { return listBindings(new CompositeName(name)); } /** * Destroys the named context and removes it from the namespace. Any * attributes associated with the name are also removed. Intermediate * contexts are not destroyed. * <p> * This method is idempotent. It succeeds even if the terminal atomic * name is not bound in the target context, but throws * NameNotFoundException if any of the intermediate contexts do not exist. * * In a federated naming system, a context from one naming system may be * bound to a name in another. One can subsequently look up and perform * operations on the foreign context using a composite name. However, an * attempt destroy the context using this composite name will fail with * NotContextException, because the foreign context is not a "subcontext" * of the context in which it is bound. Instead, use unbind() to remove * the binding of the foreign context. Destroying the foreign context * requires that the destroySubcontext() be performed on a context from * the foreign context's "native" naming system. * * @param name the name of the context to be destroyed; may not be empty * @exception NameNotFoundException if an intermediate context does not * exist * @exception NotContextException if the name is bound but does not name * a context, or does not name a context of the appropriate type */ public void destroySubcontext(Name name) throws NamingException { checkWritable(); while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) throw new NamingException(sm.getString("namingContext.invalidName")); NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (name.size() > 1) { if (entry.type == NamingEntry.CONTEXT) { ((Context) entry.value).unbind(name.getSuffix(1)); } else { throw new NamingException(sm.getString("namingContext.contextExpected")); } } else { if (entry.type == NamingEntry.CONTEXT) { ((Context) entry.value).close(); bindings.remove(name.get(0)); } else { throw new NotContextException(sm.getString("namingContext.contextExpected")); } } } /** * Destroys the named context and removes it from the namespace. * * @param name the name of the context to be destroyed; may not be empty * @exception NameNotFoundException if an intermediate context does not * exist * @exception NotContextException if the name is bound but does not name * a context, or does not name a context of the appropriate type */ public void destroySubcontext(String name) throws NamingException { destroySubcontext(new CompositeName(name)); } /** * Creates and binds a new context. Creates a new context with the given * name and binds it in the target context (that named by all but * terminal atomic component of the name). All intermediate contexts and * the target context must already exist. * * @param name the name of the context to create; may not be empty * @return the newly created context * @exception NameAlreadyBoundException if name is already bound * @exception InvalidAttributesException if creation of the subcontext * requires specification of mandatory attributes * @exception NamingException if a naming exception is encountered */ public Context createSubcontext(Name name) throws NamingException { checkWritable(); Context newContext = new NamingContext(env, this.name); bind(name, newContext); return newContext; } /** * Creates and binds a new context. * * @param name the name of the context to create; may not be empty * @return the newly created context * @exception NameAlreadyBoundException if name is already bound * @exception InvalidAttributesException if creation of the subcontext * requires specification of mandatory attributes * @exception NamingException if a naming exception is encountered */ public Context createSubcontext(String name) throws NamingException { return createSubcontext(new CompositeName(name)); } /** * Retrieves the named object, following links except for the terminal * atomic component of the name. If the object bound to name is not a * link, returns the object itself. * * @param name the name of the object to look up * @return the object bound to name, not following the terminal link * (if any). * @exception NamingException if a naming exception is encountered */ public Object lookupLink(Name name) throws NamingException { return lookup(name, false); } /** * Retrieves the named object, following links except for the terminal * atomic component of the name. * * @param name the name of the object to look up * @return the object bound to name, not following the terminal link * (if any). * @exception NamingException if a naming exception is encountered */ public Object lookupLink(String name) throws NamingException { return lookup(new CompositeName(name), false); } /** * Retrieves the parser associated with the named context. In a * federation of namespaces, different naming systems will parse names * differently. This method allows an application to get a parser for * parsing names into their atomic components using the naming convention * of a particular naming system. Within any single naming system, * NameParser objects returned by this method must be equal (using the * equals() test). * * @param name the name of the context from which to get the parser * @return a name parser that can parse compound names into their atomic * components * @exception NamingException if a naming exception is encountered */ public NameParser getNameParser(Name name) throws NamingException { while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) return nameParser; if (name.size() > 1) { Object obj = bindings.get(name.get(0)); if (obj instanceof Context) { return ((Context) obj).getNameParser(name.getSuffix(1)); } else { throw new NotContextException(sm.getString("namingContext.contextExpected")); } } return nameParser; } /** * Retrieves the parser associated with the named context. * * @param name the name of the context from which to get the parser * @return a name parser that can parse compound names into their atomic * components * @exception NamingException if a naming exception is encountered */ public NameParser getNameParser(String name) throws NamingException { return getNameParser(new CompositeName(name)); } /** * Composes the name of this context with a name relative to this context. * <p> * Given a name (name) relative to this context, and the name (prefix) * of this context relative to one of its ancestors, this method returns * the composition of the two names using the syntax appropriate for the * naming system(s) involved. That is, if name names an object relative * to this context, the result is the name of the same object, but * relative to the ancestor context. None of the names may be null. * * @param name a name relative to this context * @param prefix the name of this context relative to one of its ancestors * @return the composition of prefix and name * @exception NamingException if a naming exception is encountered */ public Name composeName(Name name, Name prefix) throws NamingException { prefix = (Name) name.clone(); return prefix.addAll(name); } /** * Composes the name of this context with a name relative to this context. * * @param name a name relative to this context * @param prefix the name of this context relative to one of its ancestors * @return the composition of prefix and name * @exception NamingException if a naming exception is encountered */ public String composeName(String name, String prefix) throws NamingException { return prefix + "/" + name; } /** * Adds a new environment property to the environment of this context. If * the property already exists, its value is overwritten. * * @param propName the name of the environment property to add; may not * be null * @param propVal the value of the property to add; may not be null * @exception NamingException if a naming exception is encountered */ public Object addToEnvironment(String propName, Object propVal) throws NamingException { return env.put(propName, propVal); } /** * Removes an environment property from the environment of this context. * * @param propName the name of the environment property to remove; * may not be null * @exception NamingException if a naming exception is encountered */ public Object removeFromEnvironment(String propName) throws NamingException { return env.remove(propName); } /** * Retrieves the environment in effect for this context. See class * description for more details on environment properties. * The caller should not make any changes to the object returned: their * effect on the context is undefined. The environment of this context * may be changed using addToEnvironment() and removeFromEnvironment(). * * @return the environment of this context; never null * @exception NamingException if a naming exception is encountered */ public Hashtable getEnvironment() throws NamingException { return env; } /** * Closes this context. This method releases this context's resources * immediately, instead of waiting for them to be released automatically * by the garbage collector. * This method is idempotent: invoking it on a context that has already * been closed has no effect. Invoking any other method on a closed * context is not allowed, and results in undefined behaviour. * * @exception NamingException if a naming exception is encountered */ public void close() throws NamingException { env.clear(); } /** * Retrieves the full name of this context within its own namespace. * <p> * Many naming services have a notion of a "full name" for objects in * their respective namespaces. For example, an LDAP entry has a * distinguished name, and a DNS record has a fully qualified name. This * method allows the client application to retrieve this name. The string * returned by this method is not a JNDI composite name and should not be * passed directly to context methods. In naming systems for which the * notion of full name does not make sense, * OperationNotSupportedException is thrown. * * @return this context's name in its own namespace; never null * @exception OperationNotSupportedException if the naming system does * not have the notion of a full name * @exception NamingException if a naming exception is encountered */ public String getNameInNamespace() throws NamingException { throw new OperationNotSupportedException(sm.getString("namingContext.noAbsoluteName")); //FIXME ? } // ------------------------------------------------------ Protected Methods /** * Retrieves the named object. * * @param name the name of the object to look up * @param resolveLinks If true, the links will be resolved * @return the object bound to name * @exception NamingException if a naming exception is encountered */ protected Object lookup(Name name, boolean resolveLinks) throws NamingException { // Removing empty parts while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) { // If name is empty, a newly allocated naming context is returned return new NamingContext(env, this.name, bindings); } NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (name.size() > 1) { // If the size of the name is greater that 1, then we go through a // number of subcontexts. if (entry.type != NamingEntry.CONTEXT) { throw new NamingException(sm.getString("namingContext.contextExpected")); } return ((Context) entry.value).lookup(name.getSuffix(1)); } else { if ((resolveLinks) && (entry.type == NamingEntry.LINK_REF)) { String link = ((LinkRef) entry.value).getLinkName(); if (link.startsWith(".")) { // Link relative to this context return lookup(link.substring(1)); } else { return (new InitialContext(env)).lookup(link); } } else if (entry.type == NamingEntry.REFERENCE) { try { Object obj = NamingManager.getObjectInstance(entry.value, name, this, env); if (obj != null) { entry.value = obj; entry.type = NamingEntry.ENTRY; } return obj; } catch (NamingException e) { throw e; } catch (Exception e) { log.warn(sm.getString("namingContext.failResolvingReference"), e); throw new NamingException(e.getMessage()); } } else { return entry.value; } } } /** * Binds a name to an object. All intermediate contexts and the target * context (that named by all but terminal atomic component of the name) * must already exist. * * @param name the name to bind; may not be empty * @param object the object to bind; possibly null * @param rebind if true, then perform a rebind (ie, overwrite) * @exception NameAlreadyBoundException if name is already bound * @exception InvalidAttributesException if object did not supply all * mandatory attributes * @exception NamingException if a naming exception is encountered */ protected void bind(Name name, Object obj, boolean rebind) throws NamingException { checkWritable(); while ((!name.isEmpty()) && (name.get(0).length() == 0)) name = name.getSuffix(1); if (name.isEmpty()) throw new NamingException(sm.getString("namingContext.invalidName")); NamingEntry entry = (NamingEntry) bindings.get(name.get(0)); if (name.size() > 1) { if (entry == null) { throw new NameNotFoundException(sm.getString("namingContext.nameNotBound", name.get(0))); } if (entry.type == NamingEntry.CONTEXT) { if (rebind) { ((Context) entry.value).rebind(name.getSuffix(1), obj); } else { ((Context) entry.value).bind(name.getSuffix(1), obj); } } else { throw new NamingException(sm.getString("namingContext.contextExpected")); } } else { if ((!rebind) && (entry != null)) { throw new NamingException(sm.getString("namingContext.alreadyBound", name.get(0))); } else { // Getting the type of the object and wrapping it within a new // NamingEntry Object toBind = NamingManager.getStateToBind(obj, name, this, env); if (toBind instanceof Context) { entry = new NamingEntry(name.get(0), toBind, NamingEntry.CONTEXT); } else if (toBind instanceof LinkRef) { entry = new NamingEntry(name.get(0), toBind, NamingEntry.LINK_REF); } else if (toBind instanceof Reference) { entry = new NamingEntry(name.get(0), toBind, NamingEntry.REFERENCE); } else if (toBind instanceof Referenceable) { toBind = ((Referenceable) toBind).getReference(); entry = new NamingEntry(name.get(0), toBind, NamingEntry.REFERENCE); } else { entry = new NamingEntry(name.get(0), toBind, NamingEntry.ENTRY); } bindings.put(name.get(0), entry); } } } /** * Returns true if writing is allowed on this context. */ protected boolean isWritable() { return ContextAccessController.isWritable(name); } /** * Throws a naming exception is Context is not writable. */ protected void checkWritable() throws NamingException { if (!isWritable()) throw new NamingException(sm.getString("namingContext.readOnly")); } }