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      1 /*
      2  * Copyright 2009 Mike Cumings
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *   http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.kenai.jbosh;
     18 
     19 import java.util.Collections;
     20 import java.util.Map;
     21 import java.util.Set;
     22 
     23 /**
     24  * Class representing a single message to or from the BOSH connection
     25  * manager (CM).
     26  * <p/>
     27  * These messages consist of a single {@code body} element
     28  * (qualified within the BOSH namespace:
     29  * {@code http://jabber.org/protocol/httpbind}) and contain zero or more
     30  * child elements (of any namespace).  These child elements constitute the
     31  * message payload.
     32  * <p/>
     33  * In addition to the message payload, the attributes of the wrapper
     34  * {@code body} element may also need to be used as part of the communication
     35  * protocol being implemented on top of BOSH, or to define additional
     36  * namespaces used by the child "payload" elements.  These attributes are
     37  * exposed via accessors.
     38  */
     39 public abstract class AbstractBody {
     40 
     41     ///////////////////////////////////////////////////////////////////////////
     42     // Constructor:
     43 
     44     /**
     45      * Restrict subclasses to the local package.
     46      */
     47     AbstractBody() {
     48         // Empty
     49     }
     50 
     51     ///////////////////////////////////////////////////////////////////////////
     52     // Public methods:
     53 
     54     /**
     55      * Get a set of all defined attribute names.
     56      *
     57      * @return set of qualified attribute names
     58      */
     59     public final Set<BodyQName> getAttributeNames() {
     60         Map<BodyQName, String> attrs = getAttributes();
     61         return Collections.unmodifiableSet(attrs.keySet());
     62     }
     63 
     64     /**
     65      * Get the value of the specified attribute.
     66      *
     67      * @param attr name of the attribute to retriece
     68      * @return attribute value, or {@code null} if not defined
     69      */
     70     public final String getAttribute(final BodyQName attr) {
     71         Map<BodyQName, String> attrs = getAttributes();
     72         return attrs.get(attr);
     73     }
     74 
     75     ///////////////////////////////////////////////////////////////////////////
     76     // Abstract methods:
     77 
     78     /**
     79      * Get a map of all defined attribute names with their corresponding values.
     80      *
     81      * @return map of qualified attributes
     82      */
     83     public abstract Map<BodyQName, String> getAttributes();
     84 
     85     /**
     86      * Get an XML String representation of this message.
     87      *
     88      * @return XML string representing the body message
     89      */
     90     public abstract String toXML();
     91 
     92     ///////////////////////////////////////////////////////////////////////////
     93     // Package-private methods:
     94 
     95     /**
     96      * Returns the qualified name of the root/wrapper element.
     97      *
     98      * @return qualified name
     99      */
    100     static BodyQName getBodyQName() {
    101         return BodyQName.createBOSH("body");
    102     }
    103 
    104 }
    105