ojluni/src/main/java/com/sun/jndi/toolkit/url/GenericURLContext.java - platform/libcore.git - Git at Google

 /*
  * Copyright (c) 1999, 2004, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code 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
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package com.sun.jndi.toolkit.url;

 import javax.naming.*;
 import javax.naming.spi.ResolveResult;
 import javax.naming.spi.NamingManager;

 import java.util.Hashtable;
 import java.net.MalformedURLException;

 /**
  * This abstract class is a generic URL context that accepts as the
  * name argument either a string URL or a Name whose first component
  * is a URL. It resolves the URL to a target context and then continues
  * the operation using the remaining name in the target context as if
  * the first component names a junction.
  *
  * A subclass must define getRootURLContext()
  * to process the URL into head/tail pieces. If it wants to control how
  * URL strings are parsed and compared for the rename() operation, then
  * it should override getNonRootURLSuffixes() and urlEquals().
  *
  * @author Scott Seligman
  * @author Rosanna Lee
  */
 abstract public class GenericURLContext implements Context {
     protected Hashtable myEnv = null;

     public GenericURLContext(Hashtable env) {
         // context that is not tied to any specific URL
         myEnv = env;  // copied on write
     }

     public void close() throws NamingException {
         myEnv = null;
     }

     public String getNameInNamespace() throws NamingException {
         return ""; // %%% check this out: A URL context's name is ""
     }

     /**
       * Resolves 'name' into a target context with remaining name.
       * For example, with a JNDI URL "jndi://dnsname/rest_name",
       * this method resolves "jndi://dnsname/" to a target context,
       * and returns the target context with "rest_name".
       * The definition of "root URL" and how much of the URL to
       * consume is implementation specific.
       * If rename() is supported for a particular URL scheme,
       * getRootURLContext(), getURLPrefix(), and getURLSuffix()
       * must be in sync wrt how URLs are parsed and returned.
       */
     abstract protected ResolveResult getRootURLContext(String url,
         Hashtable env) throws NamingException;

     /**
       * Returns the suffix of the url. The result should be identical to
       * that of calling getRootURLContext().getRemainingName(), but
       * without the overhead of doing anything with the prefix like
       * creating a context.
       *<p>
       * This method returns a Name instead of a String because to give
       * the provider an opportunity to return a Name (for example,
       * for weakly separated naming systems like COS naming).
       *<p>
       * The default implementation uses skips 'prefix', calls
       * UrlUtil.decode() on it, and returns the result as a single component
       * CompositeName.
       * Subclass should override if this is not appropriate.
       * This method is used only by rename().
       * If rename() is supported for a particular URL scheme,
       * getRootURLContext(), getURLPrefix(), and getURLSuffix()
       * must be in sync wrt how URLs are parsed and returned.
       *<p>
       * For many URL schemes, this method is very similar to URL.getFile(),
       * except getFile() will return a leading slash in the
       * 2nd, 3rd, and 4th cases. For schemes like "ldap" and "iiop",
       * the leading slash must be skipped before the name is an acceptable
       * format for operation by the Context methods. For schemes that treat the
       * leading slash as significant (such as "file"),
       * the subclass must override getURLSuffix() to get the correct behavior.
       * Remember, the behavior must match getRootURLContext().
       *
       * URL                                     Suffix
       * foo://host:port                         <empty string>
       * foo://host:port/rest/of/name            rest/of/name
       * foo:///rest/of/name                     rest/of/name
       * foo:/rest/of/name                       rest/of/name
       * foo:rest/of/name                        rest/of/name
       */
     protected Name getURLSuffix(String prefix, String url) throws NamingException {
         String suffix = url.substring(prefix.length());
         if (suffix.length() == 0) {
             return new CompositeName();
         }

         if (suffix.charAt(0) == '/') {
             suffix = suffix.substring(1); // skip leading slash
         }

         try {
             return new CompositeName().add(UrlUtil.decode(suffix));
         } catch (MalformedURLException e) {
             throw new InvalidNameException(e.getMessage());
         }
     }

     /**
       * Finds the prefix of a URL.
       * Default implementation looks for slashes and then extracts
       * prefixes using String.substring().
       * Subclass should override if this is not appropriate.
       * This method is used only by rename().
       * If rename() is supported for a particular URL scheme,
       * getRootURLContext(), getURLPrefix(), and getURLSuffix()
       * must be in sync wrt how URLs are parsed and returned.
       *<p>
       * URL                                     Prefix
       * foo://host:port                         foo://host:port
       * foo://host:port/rest/of/name            foo://host:port
       * foo:///rest/of/name                     foo://
       * foo:/rest/of/name                       foo:
       * foo:rest/of/name                        foo:
       */
     protected String getURLPrefix(String url) throws NamingException {
         int start = url.indexOf(":");

         if (start < 0) {
             throw new OperationNotSupportedException("Invalid URL: " + url);
         }
         ++start; // skip ':'

         if (url.startsWith("//", start)) {
             start += 2;  // skip double slash

             // find last slash
             int posn = url.indexOf("/", start);
             if (posn >= 0) {
                 start = posn;
             } else {
                 start = url.length();  // rest of URL
             }
         }

         // else 0 or 1 iniitial slashes; start is unchanged
         return url.substring(0, start);
     }

     /**
      * Determines whether two URLs are the same.
      * Default implementation uses String.equals().
      * Subclass should override if this is not appropriate.
      * This method is used by rename().
      */
     protected boolean urlEquals(String url1, String url2) {
         return url1.equals(url2);
     }

     /**
      * Gets the context in which to continue the operation. This method
      * is called when this context is asked to process a multicomponent
      * Name in which the first component is a URL.
      * Treat the first component like a junction: resolve it and then use
      * NamingManager.getContinuationContext() to get the target context in
      * which to operate on the remainder of the name (n.getSuffix(1)).
      */
     protected Context getContinuationContext(Name n) throws NamingException {
         Object obj = lookup(n.get(0));
         CannotProceedException cpe = new CannotProceedException();
         cpe.setResolvedObj(obj);
         cpe.setEnvironment(myEnv);
         return NamingManager.getContinuationContext(cpe);
     }

     public Object lookup(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.lookup(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public Object lookup(Name name) throws NamingException {
         if (name.size() == 1) {
             return lookup(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.lookup(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public void bind(String name, Object obj) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             ctx.bind(res.getRemainingName(), obj);
         } finally {
             ctx.close();
         }
     }

     public void bind(Name name, Object obj) throws NamingException {
         if (name.size() == 1) {
             bind(name.get(0), obj);
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 ctx.bind(name.getSuffix(1), obj);
             } finally {
                 ctx.close();
             }
         }
     }

     public void rebind(String name, Object obj) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             ctx.rebind(res.getRemainingName(), obj);
         } finally {
             ctx.close();
         }
     }

     public void rebind(Name name, Object obj) throws NamingException {
         if (name.size() == 1) {
             rebind(name.get(0), obj);
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 ctx.rebind(name.getSuffix(1), obj);
             } finally {
                 ctx.close();
             }
         }
     }

     public void unbind(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             ctx.unbind(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public void unbind(Name name) throws NamingException {
         if (name.size() == 1) {
             unbind(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 ctx.unbind(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public void rename(String oldName, String newName) throws NamingException {
         String oldPrefix = getURLPrefix(oldName);
         String newPrefix = getURLPrefix(newName);
         if (!urlEquals(oldPrefix, newPrefix)) {
             throw new OperationNotSupportedException(
                 "Renaming using different URL prefixes not supported : " +
                 oldName + " " + newName);
         }

         ResolveResult res = getRootURLContext(oldName, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             ctx.rename(res.getRemainingName(), getURLSuffix(newPrefix, newName));
         } finally {
             ctx.close();
         }
     }

     public void rename(Name name, Name newName) throws NamingException {
         if (name.size() == 1) {
             if (newName.size() != 1) {
                 throw new OperationNotSupportedException(
             "Renaming to a Name with more components not supported: " + newName);
             }
             rename(name.get(0), newName.get(0));
         } else {
             // > 1 component with 1st one being URL
             // URLs must be identical; cannot deal with diff URLs
             if (!urlEquals(name.get(0), newName.get(0))) {
                 throw new OperationNotSupportedException(
                     "Renaming using different URLs as first components not supported: " +
                     name + " " + newName);
             }

             Context ctx = getContinuationContext(name);
             try {
                 ctx.rename(name.getSuffix(1), newName.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public NamingEnumeration<NameClassPair> list(String name)   throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.list(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public NamingEnumeration<NameClassPair> list(Name name) throws NamingException {
         if (name.size() == 1) {
             return list(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.list(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public NamingEnumeration<Binding> listBindings(String name)
         throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.listBindings(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public NamingEnumeration<Binding> listBindings(Name name) throws NamingException {
         if (name.size() == 1) {
             return listBindings(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.listBindings(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public void destroySubcontext(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             ctx.destroySubcontext(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public void destroySubcontext(Name name) throws NamingException {
         if (name.size() == 1) {
             destroySubcontext(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 ctx.destroySubcontext(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public Context createSubcontext(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.createSubcontext(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public Context createSubcontext(Name name) throws NamingException {
         if (name.size() == 1) {
             return createSubcontext(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.createSubcontext(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public Object lookupLink(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.lookupLink(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public Object lookupLink(Name name) throws NamingException {
         if (name.size() == 1) {
             return lookupLink(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.lookupLink(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public NameParser getNameParser(String name) throws NamingException {
         ResolveResult res = getRootURLContext(name, myEnv);
         Context ctx = (Context)res.getResolvedObj();
         try {
             return ctx.getNameParser(res.getRemainingName());
         } finally {
             ctx.close();
         }
     }

     public NameParser getNameParser(Name name) throws NamingException {
         if (name.size() == 1) {
             return getNameParser(name.get(0));
         } else {
             Context ctx = getContinuationContext(name);
             try {
                 return ctx.getNameParser(name.getSuffix(1));
             } finally {
                 ctx.close();
             }
         }
     }

     public String composeName(String name, String prefix)
         throws NamingException {
             if (prefix.equals("")) {
                 return name;
             } else if (name.equals("")) {
                 return prefix;
             } else {
                 return (prefix + "/" + name);
             }
     }

     public Name composeName(Name name, Name prefix) throws NamingException {
         Name result = (Name)prefix.clone();
         result.addAll(name);
         return result;
     }

     public Object removeFromEnvironment(String propName)
         throws NamingException {
             if (myEnv == null) {
                 return null;
             }
             myEnv = (Hashtable)myEnv.clone();
             return myEnv.remove(propName);
     }

     public Object addToEnvironment(String propName, Object propVal)
         throws NamingException {
             myEnv = (myEnv == null) ?
                 new Hashtable(11, 0.75f) : (Hashtable)myEnv.clone();
             return myEnv.put(propName, propVal);
     }

     public Hashtable getEnvironment() throws NamingException {
         if (myEnv == null) {
             return new Hashtable(5, 0.75f);
         } else {
             return (Hashtable)myEnv.clone();
         }
     }

 /*
 // To test, declare getURLPrefix and getURLSuffix static.

     public static void main(String[] args) throws Exception {
         String[] tests = {"file://host:port",
                           "file:///rest/of/name",
                           "file://host:port/rest/of/name",
                           "file:/rest/of/name",
                           "file:rest/of/name"};
         for (int i = 0; i < tests.length; i++) {
             String pre = getURLPrefix(tests[i]);
             System.out.println(pre);
             System.out.println(getURLSuffix(pre, tests[i]));
         }
     }
 */
 }
	/*
	* Copyright (c) 1999, 2004, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.jndi.toolkit.url;

	import javax.naming.*;
	import javax.naming.spi.ResolveResult;
	import javax.naming.spi.NamingManager;

	import java.util.Hashtable;
	import java.net.MalformedURLException;

	/**
	* This abstract class is a generic URL context that accepts as the
	* name argument either a string URL or a Name whose first component
	* is a URL. It resolves the URL to a target context and then continues
	* the operation using the remaining name in the target context as if
	* the first component names a junction.
	*
	* A subclass must define getRootURLContext()
	* to process the URL into head/tail pieces. If it wants to control how
	* URL strings are parsed and compared for the rename() operation, then
	* it should override getNonRootURLSuffixes() and urlEquals().
	*
	* @author Scott Seligman
	* @author Rosanna Lee
	*/
	abstract public class GenericURLContext implements Context {
	protected Hashtable myEnv = null;

	public GenericURLContext(Hashtable env) {
	// context that is not tied to any specific URL
	myEnv = env; // copied on write
	}

	public void close() throws NamingException {
	myEnv = null;
	}

	public String getNameInNamespace() throws NamingException {
	return ""; // %%% check this out: A URL context's name is ""
	}

	/**
	* Resolves 'name' into a target context with remaining name.
	* For example, with a JNDI URL "jndi://dnsname/rest_name",
	* this method resolves "jndi://dnsname/" to a target context,
	* and returns the target context with "rest_name".
	* The definition of "root URL" and how much of the URL to
	* consume is implementation specific.
	* If rename() is supported for a particular URL scheme,
	* getRootURLContext(), getURLPrefix(), and getURLSuffix()
	* must be in sync wrt how URLs are parsed and returned.
	*/
	abstract protected ResolveResult getRootURLContext(String url,
	Hashtable env) throws NamingException;

	/**
	* Returns the suffix of the url. The result should be identical to
	* that of calling getRootURLContext().getRemainingName(), but
	* without the overhead of doing anything with the prefix like
	* creating a context.
	*<p>
	* This method returns a Name instead of a String because to give
	* the provider an opportunity to return a Name (for example,
	* for weakly separated naming systems like COS naming).
	*<p>
	* The default implementation uses skips 'prefix', calls
	* UrlUtil.decode() on it, and returns the result as a single component
	* CompositeName.
	* Subclass should override if this is not appropriate.
	* This method is used only by rename().
	* If rename() is supported for a particular URL scheme,
	* getRootURLContext(), getURLPrefix(), and getURLSuffix()
	* must be in sync wrt how URLs are parsed and returned.
	*<p>
	* For many URL schemes, this method is very similar to URL.getFile(),
	* except getFile() will return a leading slash in the
	* 2nd, 3rd, and 4th cases. For schemes like "ldap" and "iiop",
	* the leading slash must be skipped before the name is an acceptable
	* format for operation by the Context methods. For schemes that treat the
	* leading slash as significant (such as "file"),
	* the subclass must override getURLSuffix() to get the correct behavior.
	* Remember, the behavior must match getRootURLContext().
	*
	* URL Suffix
	* foo://host:port <empty string>
	* foo://host:port/rest/of/name rest/of/name
	* foo:///rest/of/name rest/of/name
	* foo:/rest/of/name rest/of/name
	* foo:rest/of/name rest/of/name
	*/
	protected Name getURLSuffix(String prefix, String url) throws NamingException {
	String suffix = url.substring(prefix.length());
	if (suffix.length() == 0) {
	return new CompositeName();
	}

	if (suffix.charAt(0) == '/') {
	suffix = suffix.substring(1); // skip leading slash
	}

	try {
	return new CompositeName().add(UrlUtil.decode(suffix));
	} catch (MalformedURLException e) {
	throw new InvalidNameException(e.getMessage());
	}
	}

	/**
	* Finds the prefix of a URL.
	* Default implementation looks for slashes and then extracts
	* prefixes using String.substring().
	* Subclass should override if this is not appropriate.
	* This method is used only by rename().
	* If rename() is supported for a particular URL scheme,
	* getRootURLContext(), getURLPrefix(), and getURLSuffix()
	* must be in sync wrt how URLs are parsed and returned.
	*<p>
	* URL Prefix
	* foo://host:port foo://host:port
	* foo://host:port/rest/of/name foo://host:port
	* foo:///rest/of/name foo://
	* foo:/rest/of/name foo:
	* foo:rest/of/name foo:
	*/
	protected String getURLPrefix(String url) throws NamingException {
	int start = url.indexOf(":");

	if (start < 0) {
	throw new OperationNotSupportedException("Invalid URL: " + url);
	}
	++start; // skip ':'

	if (url.startsWith("//", start)) {
	start += 2; // skip double slash

	// find last slash
	int posn = url.indexOf("/", start);
	if (posn >= 0) {
	start = posn;
	} else {
	start = url.length(); // rest of URL
	}
	}

	// else 0 or 1 iniitial slashes; start is unchanged
	return url.substring(0, start);
	}

	/**
	* Determines whether two URLs are the same.
	* Default implementation uses String.equals().
	* Subclass should override if this is not appropriate.
	* This method is used by rename().
	*/
	protected boolean urlEquals(String url1, String url2) {
	return url1.equals(url2);
	}

	/**
	* Gets the context in which to continue the operation. This method
	* is called when this context is asked to process a multicomponent
	* Name in which the first component is a URL.
	* Treat the first component like a junction: resolve it and then use
	* NamingManager.getContinuationContext() to get the target context in
	* which to operate on the remainder of the name (n.getSuffix(1)).
	*/
	protected Context getContinuationContext(Name n) throws NamingException {
	Object obj = lookup(n.get(0));
	CannotProceedException cpe = new CannotProceedException();
	cpe.setResolvedObj(obj);
	cpe.setEnvironment(myEnv);
	return NamingManager.getContinuationContext(cpe);
	}

	public Object lookup(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.lookup(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public Object lookup(Name name) throws NamingException {
	if (name.size() == 1) {
	return lookup(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.lookup(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public void bind(String name, Object obj) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	ctx.bind(res.getRemainingName(), obj);
	} finally {
	ctx.close();
	}
	}

	public void bind(Name name, Object obj) throws NamingException {
	if (name.size() == 1) {
	bind(name.get(0), obj);
	} else {
	Context ctx = getContinuationContext(name);
	try {
	ctx.bind(name.getSuffix(1), obj);
	} finally {
	ctx.close();
	}
	}
	}

	public void rebind(String name, Object obj) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	ctx.rebind(res.getRemainingName(), obj);
	} finally {
	ctx.close();
	}
	}

	public void rebind(Name name, Object obj) throws NamingException {
	if (name.size() == 1) {
	rebind(name.get(0), obj);
	} else {
	Context ctx = getContinuationContext(name);
	try {
	ctx.rebind(name.getSuffix(1), obj);
	} finally {
	ctx.close();
	}
	}
	}

	public void unbind(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	ctx.unbind(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public void unbind(Name name) throws NamingException {
	if (name.size() == 1) {
	unbind(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	ctx.unbind(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public void rename(String oldName, String newName) throws NamingException {
	String oldPrefix = getURLPrefix(oldName);
	String newPrefix = getURLPrefix(newName);
	if (!urlEquals(oldPrefix, newPrefix)) {
	throw new OperationNotSupportedException(
	"Renaming using different URL prefixes not supported : " +
	oldName + " " + newName);
	}

	ResolveResult res = getRootURLContext(oldName, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	ctx.rename(res.getRemainingName(), getURLSuffix(newPrefix, newName));
	} finally {
	ctx.close();
	}
	}

	public void rename(Name name, Name newName) throws NamingException {
	if (name.size() == 1) {
	if (newName.size() != 1) {
	throw new OperationNotSupportedException(
	"Renaming to a Name with more components not supported: " + newName);
	}
	rename(name.get(0), newName.get(0));
	} else {
	// > 1 component with 1st one being URL
	// URLs must be identical; cannot deal with diff URLs
	if (!urlEquals(name.get(0), newName.get(0))) {
	throw new OperationNotSupportedException(
	"Renaming using different URLs as first components not supported: " +
	name + " " + newName);
	}

	Context ctx = getContinuationContext(name);
	try {
	ctx.rename(name.getSuffix(1), newName.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public NamingEnumeration<NameClassPair> list(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.list(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public NamingEnumeration<NameClassPair> list(Name name) throws NamingException {
	if (name.size() == 1) {
	return list(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.list(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public NamingEnumeration<Binding> listBindings(String name)
	throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.listBindings(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public NamingEnumeration<Binding> listBindings(Name name) throws NamingException {
	if (name.size() == 1) {
	return listBindings(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.listBindings(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public void destroySubcontext(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	ctx.destroySubcontext(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public void destroySubcontext(Name name) throws NamingException {
	if (name.size() == 1) {
	destroySubcontext(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	ctx.destroySubcontext(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public Context createSubcontext(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.createSubcontext(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public Context createSubcontext(Name name) throws NamingException {
	if (name.size() == 1) {
	return createSubcontext(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.createSubcontext(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public Object lookupLink(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.lookupLink(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public Object lookupLink(Name name) throws NamingException {
	if (name.size() == 1) {
	return lookupLink(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.lookupLink(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public NameParser getNameParser(String name) throws NamingException {
	ResolveResult res = getRootURLContext(name, myEnv);
	Context ctx = (Context)res.getResolvedObj();
	try {
	return ctx.getNameParser(res.getRemainingName());
	} finally {
	ctx.close();
	}
	}

	public NameParser getNameParser(Name name) throws NamingException {
	if (name.size() == 1) {
	return getNameParser(name.get(0));
	} else {
	Context ctx = getContinuationContext(name);
	try {
	return ctx.getNameParser(name.getSuffix(1));
	} finally {
	ctx.close();
	}
	}
	}

	public String composeName(String name, String prefix)
	throws NamingException {
	if (prefix.equals("")) {
	return name;
	} else if (name.equals("")) {
	return prefix;
	} else {
	return (prefix + "/" + name);
	}
	}

	public Name composeName(Name name, Name prefix) throws NamingException {
	Name result = (Name)prefix.clone();
	result.addAll(name);
	return result;
	}

	public Object removeFromEnvironment(String propName)
	throws NamingException {
	if (myEnv == null) {
	return null;
	}
	myEnv = (Hashtable)myEnv.clone();
	return myEnv.remove(propName);
	}

	public Object addToEnvironment(String propName, Object propVal)
	throws NamingException {
	myEnv = (myEnv == null) ?
	new Hashtable(11, 0.75f) : (Hashtable)myEnv.clone();
	return myEnv.put(propName, propVal);
	}

	public Hashtable getEnvironment() throws NamingException {
	if (myEnv == null) {
	return new Hashtable(5, 0.75f);
	} else {
	return (Hashtable)myEnv.clone();
	}
	}

	/*
	// To test, declare getURLPrefix and getURLSuffix static.

	public static void main(String[] args) throws Exception {
	String[] tests = {"file://host:port",
	"file:///rest/of/name",
	"file://host:port/rest/of/name",
	"file:/rest/of/name",
	"file:rest/of/name"};
	for (int i = 0; i < tests.length; i++) {
	String pre = getURLPrefix(tests[i]);
	System.out.println(pre);
	System.out.println(getURLSuffix(pre, tests[i]));
	}
	}
	*/
	}