jdk/src/share/classes/javax/naming/ReferralException.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/naming/ReferralException.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,204 @@
+/*
+ * Copyright 1999-2004 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.naming;
+
+import java.util.Hashtable;
+
+/**
+ * This abstract class is used to represent a referral exception,
+ * which is generated in response to a <em>referral</em>
+ * such as that returned by LDAP v3 servers.
+ * <p>
+ * A service provider provides
+ * a subclass of <tt>ReferralException</tt> by providing implementations
+ * for <tt>getReferralInfo()</tt> and <tt>getReferralContext()</tt> (and appropriate
+ * constructors and/or corresponding "set" methods).
+ * <p>
+ * The following code sample shows how <tt>ReferralException</tt> can be used.
+ * <p><blockquote><pre>
+ *      while (true) {
+ *          try {
+ *              bindings = ctx.listBindings(name);
+ *              while (bindings.hasMore()) {
+ *                  b = bindings.next();
+ *                  ...
+ *              }
+ *              break;
+ *          } catch (ReferralException e) {
+ *              ctx = e.getReferralContext();
+ *          }
+ *      }
+ * </pre></blockquote></p>
+ *<p>
+ * <tt>ReferralException</tt> is an abstract class. Concrete implementations
+ * determine its synchronization and serialization properties.
+ *<p>
+ * An environment parameter passed to the <tt>getReferralContext()</tt>
+ * method is owned by the caller.
+ * The service provider will not modify the object or keep a reference to it,
+ * but may keep a reference to a clone of it.
+ *
+ * @author Rosanna Lee
+ * @author Scott Seligman
+ *
+ * @since 1.3
+ *
+ */
+
+public abstract class ReferralException extends NamingException {
+    /**
+     * Constructs a new instance of ReferralException using the
+     * explanation supplied. All other fields are set to null.
+     *
+     * @param   explanation     Additional detail about this exception. Can be null.
+     * @see java.lang.Throwable#getMessage
+     */
+    protected ReferralException(String explanation) {
+        super(explanation);
+    }
+
+    /**
+      * Constructs a new instance of ReferralException.
+      * All fields are set to null.
+      */
+    protected ReferralException() {
+        super();
+    }
+
+    /**
+     * Retrieves information (such as URLs) related to this referral.
+     * The program may examine or display this information
+     * to the user to determine whether to continue with the referral,
+     * or to determine additional information needs to be supplied in order
+     * to continue with the referral.
+     *
+     * @return Non-null referral information related to this referral.
+     */
+    public abstract Object getReferralInfo();
+
+    /**
+     * Retrieves the context at which to continue the method.
+     * Regardless of whether a referral is encountered directly during a
+     * context operation, or indirectly, for example, during a search
+     * enumeration, the referral exception should provide a context
+     * at which to continue the operation. The referral context is
+     * created using the environment properties of the context
+     * that threw the ReferralException.
+     *
+     *<p>
+     * To continue the operation, the client program should re-invoke
+     * the method using the same arguments as the original invocation.
+     *
+     * @return The non-null context at which to continue the method.
+     * @exception NamingException If a naming exception was encountered.
+     * Call either <tt>retryReferral()</tt> or <tt>skipReferral()</tt>
+     * to continue processing referrals.
+     */
+    public abstract Context getReferralContext() throws NamingException;
+
+    /**
+     * Retrieves the context at which to continue the method using
+     * environment properties.
+     * Regardless of whether a referral is encountered directly during a
+     * context operation, or indirectly, for example, during a search
+     * enumeration, the referral exception should provide a context
+     * at which to continue the operation.
+     *<p>
+     * The referral context is created using <tt>env</tt> as its environment
+     * properties.
+     * This method should be used instead of the no-arg overloaded form
+     * when the caller needs to use different environment properties for
+     * the referral context. It might need to do this, for example, when
+     * it needs to supply different authentication information to the referred
+     * server in order to create the referral context.
+     *<p>
+     * To continue the operation, the client program should re-invoke
+     * the method using the same arguments as the original invocation.
+     *
+     * @param env The possibly null environment to use when retrieving the
+     *          referral context. If null, no environment properties will be used.
+     *
+     * @return The non-null context at which to continue the method.
+     * @exception NamingException If a naming exception was encountered.
+     * Call either <tt>retryReferral()</tt> or <tt>skipReferral()</tt>
+     * to continue processing referrals.
+     */
+    public abstract Context
+        getReferralContext(Hashtable<?,?> env)
+        throws NamingException;
+
+    /**
+     * Discards the referral about to be processed.
+     * A call to this method should be followed by a call to
+     * <code>getReferralContext</code> to allow the processing of
+     * other referrals to continue.
+     * The following code fragment shows a typical usage pattern.
+     * <p><blockquote><pre>
+     *  } catch (ReferralException e) {
+     *      if (!shallIFollow(e.getReferralInfo())) {
+     *          if (!e.skipReferral()) {
+     *              return;
+     *          }
+     *      }
+     *      ctx = e.getReferralContext();
+     *  }
+     * </pre></blockquote>
+     *
+     * @return true If more referral processing is pending; false otherwise.
+     */
+    public abstract boolean skipReferral();
+
+    /**
+     * Retries the referral currently being processed.
+     * A call to this method should be followed by a call to
+     * <code>getReferralContext</code> to allow the current
+     * referral to be retried.
+     * The following code fragment shows a typical usage pattern.
+     * <p><blockquote><pre>
+     *  } catch (ReferralException e) {
+     *      while (true) {
+     *          try {
+     *              ctx = e.getReferralContext(env);
+     *              break;
+     *          } catch (NamingException ne) {
+     *              if (! shallIRetry()) {
+     *                  return;
+     *              }
+     *              // modify environment properties (env), if necessary
+     *              e.retryReferral();
+     *          }
+     *      }
+     *  }
+     * </pre></blockquote>
+     *
+     */
+    public abstract void retryReferral();
+
+    /**
+     * Use serialVersionUID from JNDI 1.1.1 for interoperability
+     */
+    private static final long serialVersionUID = -2881363844695698876L;
+}