org.apache.axiom.om.OMAbstractFactory Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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 org.apache.axiom.soap.SOAPFactory;
/**
* Provides default instances for object model and meta factories.
*
* The {@link #getMetaFactory()} method returns the default {@link OMMetaFactory} instance.
* See the Javadoc of the {@link #getMetaFactory()} method for details about how this
* instance is determined.
*
* The {@link #getOMFactory()}, {@link #getSOAP11Factory()} and {@link #getSOAP12Factory()}
* methods return default instances for plain XML, SOAP 1.1 and SOAP 1.2 object model factories.
* They are convenience methods calling {@link #getMetaFactory()} and then delegating to the
* returned {@link OMMetaFactory}.
*
* Note that while {@link #getMetaFactory()} always returns the same instance, the other methods
* may return new instances on every invocation, depending on the {@link OMMetaFactory}
* implementation.
*
*/
public class OMAbstractFactory {
public static final String META_FACTORY_NAME_PROPERTY = "org.apache.axiom.om.OMMetaFactory";
private static final String DEFAULT_META_FACTORY_CLASS_NAME =
"org.apache.axiom.om.impl.llom.factory.OMLinkedListMetaFactory";
/**
* The default {@link OMMetaFactory} instance determined by the system
* property {@link #META_FACTORY_NAME_PROPERTY}, or if no such system
* property is set, by the value of the
* {@link #DEFAULT_META_FACTORY_CLASS_NAME} constant.
*/
private static OMMetaFactory defaultMetaFactory;
/**
* The {@link OMMetaFactory} set through
* {@link #setMetaFactory(OMMetaFactory)}. If this is null,
* then {@link #defaultMetaFactory} will be returned by
* {@link #getMetaFactory()}.
*/
private static OMMetaFactory metaFactory;
private OMAbstractFactory() {}
/**
* Explicitly set a meta factory instance. The new instance will be returned
* by all subsequent calls to {@link #getMetaFactory()}. Note that this is
* an application wide setting. More precisely, the configured meta factory
* will be used by all classes loaded from the class loader where Axiom is
* deployed and all its child class loaders. Therefore this method should be
* used with care and only be invoked during the initialization of the
* application.
*
* When Axiom is deployed as a bundle in an OSGi environment, this method
* will be used to inject the meta factory instance from the implementation
* bundle.
*
* @param newMetaFactory
* the new meta factory instance, or null to revert
* to the default meta factory instance determined by the
* org.apache.axiom.om.OMMetaFactory system property
*/
public static void setMetaFactory(OMMetaFactory newMetaFactory) {
metaFactory = newMetaFactory;
}
/**
* Get the default meta factory instance. The default instance is determined
* using the following algorithm:
*
* - If an instance has been set using
* {@link #setMetaFactory(OMMetaFactory)}, then that instance is returned.
* Note that this will be the case in an OSGi runtime, where
* {@link #setMetaFactory(OMMetaFactory)} is invoked by a helper component
* that is part of Axiom.
*
- If no instance has been set using
* {@link #setMetaFactory(OMMetaFactory)}, then the implementation class is
* determined by the
org.apache.axiom.om.OMMetaFactory system
* property.
* - If the
org.apache.axiom.om.OMMetaFactory system property
* is not set, the meta factory for the LLOM implementation is returned.
*
* This method uses {@link System#getProperty(String)} to determine the
* value of the org.apache.axiom.om.OMMetaFactory system
* property. A {@link SecurityException} thrown by this method is simply
* ignored and the default factory implementation is used.
*
* @return the default OM factory instance
* @throws OMException
* if the factory's implementation class can't be found or if
* the class can't be instantiated
*/
public static OMMetaFactory getMetaFactory() {
if (metaFactory != null) {
return metaFactory;
}
if (defaultMetaFactory != null) {
return defaultMetaFactory;
}
String omFactory;
try {
omFactory = System.getProperty(META_FACTORY_NAME_PROPERTY);
if (omFactory == null || "".equals(omFactory)) {
omFactory = DEFAULT_META_FACTORY_CLASS_NAME;
}
} catch (SecurityException e) {
omFactory = DEFAULT_META_FACTORY_CLASS_NAME;
}
try {
defaultMetaFactory = (OMMetaFactory) Class.forName(omFactory).newInstance();
} catch (InstantiationException e) {
throw new OMException(e);
} catch (IllegalAccessException e) {
throw new OMException(e);
} catch (ClassNotFoundException e) {
throw new OMException(e);
}
return defaultMetaFactory;
}
/**
* Get the default OM factory instance.
*
* @return the default OM factory instance
* @throws OMException if the factory's implementation class can't be found
* or if the class can't be instantiated
*/
public static OMFactory getOMFactory() {
return getMetaFactory().getOMFactory();
}
/**
* Get the default SOAP 1.1 OM factory instance.
*
* @return the default SOAP 1.1 OM factory instance
* @throws OMException if the factory's implementation class can't be found
* or if the class can't be instantiated
*/
public static SOAPFactory getSOAP11Factory() {
return getMetaFactory().getSOAP11Factory();
}
/**
* Get the default SOAP 1.2 OM factory instance.
*
* @return the default SOAP 1.2 OM factory instance
* @throws OMException if the factory's implementation class can't be found
* or if the class can't be instantiated
*/
public static SOAPFactory getSOAP12Factory() {
return getMetaFactory().getSOAP12Factory();
}
}