/** | |
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); | |
* you may not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
package org.jivesoftware.smackx.pubsub; | |
import org.jivesoftware.smack.packet.Message; | |
import org.jivesoftware.smackx.pubsub.provider.ItemProvider; | |
/** | |
* This class represents an item that has been, or will be published to a | |
* pubsub node. An <tt>Item</tt> has several properties that are dependent | |
* on the configuration of the node to which it has been or will be published. | |
* | |
* <h1>An Item received from a node (via {@link LeafNode#getItems()} or {@link LeafNode#addItemEventListener(org.jivesoftware.smackx.pubsub.listener.ItemEventListener)}</b> | |
* <li>Will always have an id (either user or server generated) unless node configuration has both | |
* {@link ConfigureForm#isPersistItems()} and {@link ConfigureForm#isDeliverPayloads()}set to false. | |
* <li>Will have a payload if the node configuration has {@link ConfigureForm#isDeliverPayloads()} set | |
* to true, otherwise it will be null. | |
* | |
* <h1>An Item created to send to a node (via {@link LeafNode#send()} or {@link LeafNode#publish()}</b> | |
* <li>The id is optional, since the server will generate one if necessary, but should be used if it is | |
* meaningful in the context of the node. This value must be unique within the node that it is sent to, since | |
* resending an item with the same id will overwrite the one that already exists if the items are persisted. | |
* <li>Will require payload if the node configuration has {@link ConfigureForm#isDeliverPayloads()} set | |
* to true. | |
* | |
* <p>To customise the payload object being returned from the {@link #getPayload()} method, you can | |
* add a custom parser as explained in {@link ItemProvider}. | |
* | |
* @author Robin Collier | |
*/ | |
public class Item extends NodeExtension | |
{ | |
private String id; | |
/** | |
* Create an empty <tt>Item</tt> with no id. This is a valid item for nodes which are configured | |
* so that {@link ConfigureForm#isDeliverPayloads()} is false. In most cases an id will be generated by the server. | |
* For nodes configured with {@link ConfigureForm#isDeliverPayloads()} and {@link ConfigureForm#isPersistItems()} | |
* set to false, no <tt>Item</tt> is sent to the node, you have to use {@link LeafNode#send()} or {@link LeafNode#publish()} | |
* methods in this case. | |
*/ | |
public Item() | |
{ | |
super(PubSubElementType.ITEM); | |
} | |
/** | |
* Create an <tt>Item</tt> with an id but no payload. This is a valid item for nodes which are configured | |
* so that {@link ConfigureForm#isDeliverPayloads()} is false. | |
* | |
* @param itemId The id if the item. It must be unique within the node unless overwriting and existing item. | |
* Passing null is the equivalent of calling {@link #Item()}. | |
*/ | |
public Item(String itemId) | |
{ | |
// The element type is actually irrelevant since we override getNamespace() to return null | |
super(PubSubElementType.ITEM); | |
id = itemId; | |
} | |
/** | |
* Create an <tt>Item</tt> with an id and a node id. | |
* <p> | |
* <b>Note:</b> This is not valid for publishing an item to a node, only receiving from | |
* one as part of {@link Message}. If used to create an Item to publish | |
* (via {@link LeafNode#publish(Item)}, the server <i>may</i> return an | |
* error for an invalid packet. | |
* | |
* @param itemId The id of the item. | |
* @param nodeId The id of the node which the item was published to. | |
*/ | |
public Item(String itemId, String nodeId) | |
{ | |
super(PubSubElementType.ITEM_EVENT, nodeId); | |
id = itemId; | |
} | |
/** | |
* Get the item id. Unique to the node it is associated with. | |
* | |
* @return The id | |
*/ | |
public String getId() | |
{ | |
return id; | |
} | |
@Override | |
public String getNamespace() | |
{ | |
return null; | |
} | |
@Override | |
public String toXML() | |
{ | |
StringBuilder builder = new StringBuilder("<item"); | |
if (id != null) | |
{ | |
builder.append(" id='"); | |
builder.append(id); | |
builder.append("'"); | |
} | |
if (getNode() != null) { | |
builder.append(" node='"); | |
builder.append(getNode()); | |
builder.append("'"); | |
} | |
builder.append("/>"); | |
return builder.toString(); | |
} | |
@Override | |
public String toString() | |
{ | |
return getClass().getName() + " | Content [" + toXML() + "]"; | |
} | |
} |