/*
* Copyright (c) 2005-2008, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. 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.wso2.carbon.mediation.initializer.persistence;
import org.apache.synapse.config.SynapseConfiguration;
import org.apache.synapse.config.xml.MultiXMLConfigurationSerializer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.axiom.om.OMElement;
import org.wso2.carbon.mediation.initializer.persistence.registry.AbstractRegistryStore;
/**
* The abstract class which can be used to access a persistence storage of a
* specific type of mediation configuration elements. Implementations of this
* abstract class should ideally be parameterized to prevent it from handling
* more than one type of objects. This abstract class provides supports basic
* persistence activities of save and delete. Registry persistence activities
* can also be handled by this implementation if required.
*
* @param <T>
*/
public abstract class AbstractStore<T> {
protected Log log = LogFactory.getLog(this.getClass());
protected String configPath;
protected AbstractRegistryStore registryStore;
protected MultiXMLConfigurationSerializer serializer;
public AbstractStore(String configPath) {
this.configPath = configPath;
serializer = new MultiXMLConfigurationSerializer(configPath);
}
public void save(String name, SynapseConfiguration config) {
if (name == null) {
log.warn("Name of the configuration item to be saved is not given");
return;
}
T obj = getObjectToPersist(name, config);
if (obj == null) {
log.warn("Unable to find the item: " + name + " for persistence");
return;
}
OMElement element = null;
String fileName = getFileName(obj);
if (fileName == null) {
// This is an element declared in the top level synapse.xml file
// So we need to rewrite the entire synapse.xml file
try {
serializer.serializeSynapseXML(config);
} catch (Exception e) {
handleException("Error while saving the mediation configuration to " +
"the file system", e);
}
} else {
// This is an element declared in its own file
// Just write the content to the file
element = saveToFile(obj, config);
}
// Save the element to the registry
if (registryStore != null) {
if (element == null) {
element = serialize(obj);
}
saveToRegistry(name, element, fileName);
}
}
public void delete(String name, String fileName, SynapseConfiguration config) {
if (fileName == null) {
// This is an element declared in the top level synapse.xml file
// So we need to rewrite the entire synapse.xml file
try {
serializer.serializeSynapseXML(config);
} catch (Exception e) {
handleException("Error while saving the mediation configuration to " +
"the file system", e);
}
} else {
// This is an element declared in its own file
// Just delete the file
deleteFile(fileName, config);
}
if (registryStore != null) {
deleteFromRegistry(name);
}
}
/**
* Serialize and save the given object to the local file system
*
* @param obj Object to be saved
* @param synapseConfig synapse configuration
* @return The OMElement generated as a result of the serialization or null
*/
protected abstract OMElement saveToFile(T obj, SynapseConfiguration synapseConfig);
/**
* Delete the specified file from the persistence store. File name is
* provided as an argument and it is up to the implementation to the
* calculate the exact file path using the file name and other available
* data.
*
* @param fileName Name of the file to be deleted
* @param config synapse configuration
*/
protected abstract void deleteFile(String fileName, SynapseConfiguration config);
/**
* Find the specified object from the SynaspeConfiguration to be saved to
* the persistence store
*
* @param name Name or unique ID of the object
* @param config Current SynapseConfiguration
* @return The named object or null if such an object doesn't exist
*/
protected abstract T getObjectToPersist(String name, SynapseConfiguration config);
/**
* Inspect the given object and find the file name to which it should be
* serialized to
*
* @param obj The object to be inspected
* @return A file name as a string or null if no file name is specified
*/
protected abstract String getFileName(T obj);
/**
* Serialize the given object into XML
*
* @param obj The object to be serialized
* @return The resulting OMElement
*/
protected abstract OMElement serialize(T obj);
public void saveItemToRegistry(String name, SynapseConfiguration config) {
if (registryStore == null) {
return;
}
if (name == null) {
log.warn("Name of the configuration item is not given");
return;
}
T obj = getObjectToPersist(name, config);
if (obj == null) {
log.warn("Unable to find the item: " + name + " for persistence");
return;
}
OMElement element = serialize(obj);
saveToRegistry(name, element, getFileName(obj));
}
public void deleteItemFromRegistry(String name) {
if (registryStore != null) {
deleteFromRegistry(name);
}
}
protected void saveToRegistry(String name, OMElement element, String fileName) {
if (element != null && registryStore != null) {
if (name == null) {
log.warn("Name of the configuration item to be saved is not given");
return;
}
registryStore.persistElement(name, element, fileName);
}
}
protected void deleteFromRegistry(String name) {
if (registryStore != null) {
if (name == null) {
log.warn("Name of the configuration item to be deleted is not given");
return;
}
registryStore.deleteElement(name);
}
}
protected void handleException(String msg, Exception e) {
log.error(msg, e);
throw new ServiceBusPersistenceException(msg, e);
}
}