org.apache.axiom.om.OMDataSourceExt Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.axiom.om;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
/**
* Interface to a backing object that can can be read and written as XML.
*
* To plug an arbitrary object into an OM tree. Follow these steps
* 1) Provide a class that implements OMDataSourceExt.
* 2) Use OMFactory.createOMElement(OMDataSource, String, OMNamespace) to build an
* OMSourcedElement.
* 3) Add the OMSourcedElement to the OM tree.
*
* OMDataSourceExt provides additional methods that are not available on the
* original OMDataSource.
*
* @see OMDataSource
* @see OMSourcedElement
*/
public interface OMDataSourceExt extends OMDataSource {
/**
* @deprecated To create an {@link OMSourcedElement} with unknown prefix, use
* {@link OMFactory#createOMElement(OMDataSource, String, OMNamespace)} and pass
* null as prefix.
*/
String LOSSY_PREFIX = "lossyPrefix";
/**
* Get the object that backs this data source. Application code should in general not call this
* method directly, but use {@link OMSourcedElement#getObject(Class)} instead.
*
* Data sources that support non destructive read/write should return the object from which the
* XML is produced. Data sources with destructive read/write should return a non null value only
* if the backing object has not been consumed yet (even partially).
*
* @return the backing object, or null if the data source has no backing object or
* if the backing object can't be accessed in a safe way
*/
Object getObject();
/**
* Returns true if reading the backing object is destructive.
* An example of an object with a destructive read is an InputSteam.
* The owning OMSourcedElement uses this information to detemine if OM tree
* expansion is needed when reading the OMDataSourceExt.
* @return boolean
*/
boolean isDestructiveRead();
/**
* Returns true if writing the backing object is destructive.
* An example of an object with a destructive write is an InputStream.
* The owning OMSourcedElement uses this information to detemine if OM tree
* expansion is needed when writing the OMDataSourceExt.
* @return boolean
*/
boolean isDestructiveWrite();
/**
* Returns a InputStream representing the xml data
* @param encoding String encoding of InputStream
* @return InputStream
*/
InputStream getXMLInputStream(String encoding) throws UnsupportedEncodingException;
/**
* Returns a byte[] representing the xml data
* @param encoding String encoding of InputStream
* @return byte[]
* @see #getXMLInputStream(String)
*/
byte[] getXMLBytes(String encoding) throws UnsupportedEncodingException;
/**
* Close the DataSource and free its resources.
*/
void close();
/**
* Create a copy of the data source. This method is used by
* {@link OMInformationItem#clone(OMCloneOptions)} when the
* {@link OMCloneOptions#isCopyOMDataSources()} option is enabled. If the data source is
* immutable and stateless, then it may return a reference to itself instead of creating a new
* data source instance.
*
* @return the copy of the data source, or null if the data source can't be copied
* (e.g. because it is destructive)
*/
OMDataSourceExt copy();
/**
* Returns true if property is set
* @param key
* @return TODO
*/
boolean hasProperty(String key);
/**
* Query a property stored on the OMDataSource
* @param key
* @return value or null
*/
Object getProperty(String key);
/**
* Set a property on the OMDataSource
* @param key
* @param value
* @return old property object or null
*/
Object setProperty(String key, Object value);
}