/* | |
* 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.felix.ipojo.handlers.lifecycle.controller; | |
import java.util.Dictionary; | |
import org.apache.felix.ipojo.ComponentInstance; | |
import org.apache.felix.ipojo.ConfigurationException; | |
import org.apache.felix.ipojo.InstanceManager; | |
import org.apache.felix.ipojo.PrimitiveHandler; | |
import org.apache.felix.ipojo.architecture.ComponentTypeDescription; | |
import org.apache.felix.ipojo.metadata.Element; | |
import org.apache.felix.ipojo.parser.FieldMetadata; | |
import org.apache.felix.ipojo.parser.PojoMetadata; | |
/** | |
* Lifecycle Controller handler. | |
* This handler allow a POJO to vote for the instance state. By setting a boolean field to true or false, the handler state changed. | |
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> | |
*/ | |
public class ControllerHandler extends PrimitiveHandler { | |
/** | |
* Actual handler (i.e. field value) state | |
*/ | |
private boolean m_state; | |
/** | |
* Configure method. | |
* Look for the first 'controller' element. | |
* @param metadata : metadata | |
* @param configuration : configuration | |
* @throws ConfigurationException : the field attribute is missing or does not exist in the class. | |
* @see org.apache.felix.ipojo.Handler#configure(org.apache.felix.ipojo.InstanceManager, org.apache.felix.ipojo.metadata.Element, java.util.Dictionary) | |
*/ | |
public void configure(Element metadata, Dictionary configuration) throws ConfigurationException { | |
Element[] controller = metadata.getElements("controller"); | |
String field = controller[0].getAttribute("field"); | |
getInstanceManager().register(new FieldMetadata(field, "boolean"), this); | |
} | |
/** | |
* Start method. | |
* Nothing to do. | |
* @see org.apache.felix.ipojo.Handler#start() | |
*/ | |
public void start() { | |
m_state = true; | |
} | |
/** | |
* Stop method. | |
* Nothing to do. | |
* @see org.apache.felix.ipojo.Handler#stop() | |
*/ | |
public void stop() { | |
// Nothing to do. | |
} | |
/** | |
* GetterCallback. | |
* @param pojo : the pojo object on which the field is accessed | |
* Return the stored value. | |
* @param field : field name. | |
* @param value : value given by the previous handler. | |
* @return : the handler state. | |
*/ | |
public Object onGet(Object pojo, String field, Object value) { | |
return new Boolean(m_state); | |
} | |
/** | |
* SetterCallback. | |
* @param pojo : the pojo object on which the field is accessed | |
* Store the new field value & invalidate / validate the handler is required. | |
* @param field : field name. | |
* @param value : new value. | |
*/ | |
public void onSet(Object pojo, String field, Object value) { | |
if (value instanceof Boolean) { | |
boolean newValue = ((Boolean) value).booleanValue(); | |
if (newValue != m_state) { | |
m_state = newValue; | |
if (m_state) { | |
((InstanceManager) getHandlerManager()).setState(ComponentInstance.VALID); | |
} else { | |
((InstanceManager) getHandlerManager()).setState(ComponentInstance.INVALID); | |
} | |
} | |
} else { | |
error("Boolean expected for the lifecycle controller"); | |
getInstanceManager().stop(); | |
} | |
} | |
/** | |
* Initialize the component factory. | |
* The controller field is checked to avoid configure check. | |
* @param desc : component description | |
* @param metadata : component type metadata | |
* @throws ConfigurationException : occurs if the controller field is not in the POJO class or is not a boolean. | |
* @see org.apache.felix.ipojo.Handler#initializeComponentFactory(org.apache.felix.ipojo.architecture.ComponentTypeDescription, org.apache.felix.ipojo.metadata.Element) | |
*/ | |
public void initializeComponentFactory(ComponentTypeDescription desc, Element metadata) throws ConfigurationException { | |
String field = null; | |
Element[] controller = metadata.getElements("controller"); | |
// Use only the first controller | |
field = controller[0].getAttribute("field"); | |
if (field == null) { | |
throw new ConfigurationException("Lifecycle controller : the controller element needs to have a field attribute"); | |
} | |
PojoMetadata method = getFactory().getPojoMetadata(); | |
FieldMetadata fieldMetadata = method.getField(field); | |
if (fieldMetadata == null) { | |
throw new ConfigurationException("Lifecycle controller : The field " + field + " does not exist in the class"); | |
} | |
if (!fieldMetadata.getFieldType().equalsIgnoreCase("boolean")) { | |
throw new ConfigurationException("Lifecycle controller : The field " + field + " must be a boolean (" + fieldMetadata.getFieldType() + " found)"); | |
} | |
} | |
} |