src/share/jaf_classes/javax/activation/CommandInfo.java

Wed, 27 Apr 2016 01:27:09 +0800

author
aoqi
date
Wed, 27 Apr 2016 01:27:09 +0800
changeset 0
373ffda63c9a
permissions
-rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/jaxws/
changeset: 657:d47a47f961ee
tag: jdk8u25-b17

     1 /*
     2  * Copyright (c) 1997, 1999, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    26 package javax.activation;
    28 import java.io.*;
    29 import java.beans.Beans;
    31 /**
    32  * The CommandInfo class is used by CommandMap implementations to
    33  * describe the results of command requests. It provides the requestor
    34  * with both the verb requested, as well as an instance of the
    35  * bean. There is also a method that will return the name of the
    36  * class that implements the command but <i>it is not guaranteed to
    37  * return a valid value</i>. The reason for this is to allow CommandMap
    38  * implmentations that subclass CommandInfo to provide special
    39  * behavior. For example a CommandMap could dynamically generate
    40  * JavaBeans. In this case, it might not be possible to create an
    41  * object with all the correct state information solely from the class
    42  * name.
    43  *
    44  * @since 1.6
    45  */
    47 public class CommandInfo {
    48     private String verb;
    49     private String className;
    51     /**
    52      * The Constructor for CommandInfo.
    53      * @param verb The command verb this CommandInfo decribes.
    54      * @param className The command's fully qualified class name.
    55      */
    56     public CommandInfo(String verb, String className) {
    57         this.verb = verb;
    58         this.className = className;
    59     }
    61     /**
    62      * Return the command verb.
    63      *
    64      * @return the command verb.
    65      */
    66     public String getCommandName() {
    67         return verb;
    68     }
    70     /**
    71      * Return the command's class name. <i>This method MAY return null in
    72      * cases where a CommandMap subclassed CommandInfo for its
    73      * own purposes.</i> In other words, it might not be possible to
    74      * create the correct state in the command by merely knowing
    75      * its class name. <b>DO NOT DEPEND ON THIS METHOD RETURNING
    76      * A VALID VALUE!</b>
    77      *
    78      * @return The class name of the command, or <i>null</i>
    79      */
    80     public String getCommandClass() {
    81         return className;
    82     }
    84     /**
    85      * Return the instantiated JavaBean component.
    86      * <p>
    87      * Begin by instantiating the component with
    88      * <code>Beans.instantiate()</code>.
    89      * <p>
    90      * If the bean implements the <code>javax.activation.CommandObject</code>
    91      * interface, call its <code>setCommandContext</code> method.
    92      * <p>
    93      * If the DataHandler parameter is null, then the bean is
    94      * instantiated with no data. NOTE: this may be useful
    95      * if for some reason the DataHandler that is passed in
    96      * throws IOExceptions when this method attempts to
    97      * access its InputStream. It will allow the caller to
    98      * retrieve a reference to the bean if it can be
    99      * instantiated.
   100      * <p>
   101      * If the bean does NOT implement the CommandObject interface,
   102      * this method will check if it implements the
   103      * java.io.Externalizable interface. If it does, the bean's
   104      * readExternal method will be called if an InputStream
   105      * can be acquired from the DataHandler.<p>
   106      *
   107      * @param dh        The DataHandler that describes the data to be
   108      *                  passed to the command.
   109      * @param loader    The ClassLoader to be used to instantiate the bean.
   110      * @return The bean
   111      * @see java.beans.Beans#instantiate
   112      * @see javax.activation.CommandObject
   113      */
   114     public Object getCommandObject(DataHandler dh, ClassLoader loader)
   115                         throws IOException, ClassNotFoundException {
   116         Object new_bean = null;
   118         // try to instantiate the bean
   119         new_bean = java.beans.Beans.instantiate(loader, className);
   121         // if we got one and it is a CommandObject
   122         if (new_bean != null) {
   123             if (new_bean instanceof CommandObject) {
   124                 ((CommandObject)new_bean).setCommandContext(verb, dh);
   125             } else if (new_bean instanceof Externalizable) {
   126                 if (dh != null) {
   127                     InputStream is = dh.getInputStream();
   128                     if (is != null) {
   129                         ((Externalizable)new_bean).readExternal(
   130                                                new ObjectInputStream(is));
   131                     }
   132                 }
   133             }
   134         }
   136         return new_bean;
   137     }
   138 }

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