/*
* 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.handler.temporal;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Dictionary;
import java.util.List;
import org.apache.felix.ipojo.ConfigurationException;
import org.apache.felix.ipojo.PrimitiveHandler;
import org.apache.felix.ipojo.metadata.Element;
import org.apache.felix.ipojo.parser.FieldMetadata;
import org.apache.felix.ipojo.parser.MethodMetadata;
import org.apache.felix.ipojo.parser.PojoMetadata;
import org.apache.felix.ipojo.util.DependencyModel;
import org.apache.felix.ipojo.util.DependencyStateListener;
import org.osgi.framework.Filter;
import org.osgi.framework.InvalidSyntaxException;
/**
* Temporal dependency handler.
* A temporal dependency waits (block) for the availability of the service.
* If no provider arrives in the specified among of time, a runtime exception is thrown.
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class TemporalHandler extends PrimitiveHandler implements DependencyStateListener {
/**
* Default timeout if not specified.
*/
public static final int DEFAULT_TIMEOUT = 3000;
/**
* No policy.
*/
public static final int NO_POLICY = 0;
/**
* Uses a nullable object.
*/
public static final int NULLABLE = 1;
/**
* Uses a default-implementation object.
*/
public static final int DEFAULT_IMPLEMENTATION = 2;
/**
* Uses an empty array.
*/
public static final int EMPTY = 3;
/**
* Uses {@code null}.
*/
public static final int NULL = 4;
/**
* The handler namespace.
*/
public static final String NAMESPACE = "org.apache.felix.ipojo.handler.temporal";
/**
* The list of managed dependencies.
*/
private List/*<deps>*/ m_dependencies = new ArrayList(1);
/**
* Start method. Starts managed dependencies.
* @see org.apache.felix.ipojo.Handler#start()
*/
public void start() {
for (int i = 0; i < m_dependencies.size(); i++) {
((TemporalDependency) m_dependencies.get(i)).start();
}
}
/**
* Stop method. Stops managed dependencies.
* @see org.apache.felix.ipojo.Handler#stop()
*/
public void stop() {
for (int i = 0; i < m_dependencies.size(); i++) {
((TemporalDependency) m_dependencies.get(i)).stop();
}
m_dependencies.clear();
}
/**
* Configure method. Creates managed dependencies.
* @param meta the component type metadata.
* @param dictionary the instance configuration.
* @throws ConfigurationException if the dependency is not configured correctly
* @see org.apache.felix.ipojo.Handler#configure(org.apache.felix.ipojo.metadata.Element, java.util.Dictionary)
*/
public void configure(Element meta, Dictionary dictionary) throws ConfigurationException {
PojoMetadata manipulation = getFactory().getPojoMetadata();
Element[] deps = meta.getElements("requires", NAMESPACE);
for (int i = 0; i < deps.length; i++) {
if (!deps[i].containsAttribute("field") || m_dependencies.contains(deps[i].getAttribute("field"))) {
error("One temporal dependency must be attached to a field or the field is already used");
return;
}
String field = deps[i].getAttribute("field");
FieldMetadata fieldmeta = manipulation.getField(field);
if (fieldmeta == null) {
error("The field " + field + " does not exist in the class " + getInstanceManager().getClassName());
return;
}
String fil = deps[i].getAttribute("filter");
Filter filter = null;
if (fil != null) {
try {
filter = getInstanceManager().getContext().createFilter(fil);
} catch (InvalidSyntaxException e) {
error("Cannot create the field from " + fil + ": " + e.getMessage());
return;
}
}
boolean agg = false;
boolean collection = false;
String spec = fieldmeta.getFieldType();
if (spec.endsWith("[]")) {
agg = true;
spec = spec.substring(0, spec.length() - 2);
} else if (Collection.class.getName().equals(spec)) {
agg = true;
collection = true;
// Collection detected. Check for the specification attribute
spec = deps[i].getAttribute("specification");
if (spec == null) {
error("A dependency injected inside a Collection must contain the 'specification' attribute");
}
}
String prox = deps[i].getAttribute("proxy");
boolean proxy = prox != null && prox.equals("true");
if (proxy && agg) {
if (! collection) {
error("Proxied aggregate temporal dependencies cannot be an array. Only collections are supported");
}
}
long timeout = DEFAULT_TIMEOUT;
if (deps[i].containsAttribute("timeout")) {
String to = deps[i].getAttribute("timeout");
if (to.equalsIgnoreCase("infinite") || to.equalsIgnoreCase("-1")) {
timeout = Long.MAX_VALUE; // Infinite wait time ...
} else {
timeout = new Long(deps[i].getAttribute("timeout")).longValue();
}
}
int policy = NO_POLICY;
String di = null;
String onTimeout = deps[i].getAttribute("onTimeout");
if (onTimeout != null) {
if (onTimeout.equalsIgnoreCase("nullable")) {
policy = NULLABLE;
} else if (onTimeout.equalsIgnoreCase("empty-array") || onTimeout.equalsIgnoreCase("empty")) {
policy = EMPTY;
if (! agg) {
// The empty array policy can only be used on aggregate dependencies
error("Cannot use the empty array policy for " + field + " : non aggregate dependency.");
}
} else if (onTimeout.equalsIgnoreCase("null")) {
policy = NULL;
} else if (onTimeout.length() > 0) {
di = onTimeout;
policy = DEFAULT_IMPLEMENTATION;
}
}
Class specification = DependencyModel.loadSpecification(spec, getInstanceManager().getContext());
TemporalDependency dep = new TemporalDependency(specification, agg, collection, proxy, filter, getInstanceManager().getContext(), timeout, policy, di, this);
m_dependencies.add(dep);
if (! proxy) { // Register method interceptor only if are not a proxy
MethodMetadata[] methods = manipulation.getMethods();
for (int k = 0; k < methods.length; k++) {
getInstanceManager().register(methods[k], dep);
}
}
getInstanceManager().register(fieldmeta, dep);
}
}
/**
* Nothing to do.
* A temporal dependency is always valid.
* @param dependencymodel dependency.
* @see org.apache.felix.ipojo.util.DependencyStateListener#invalidate(org.apache.felix.ipojo.util.DependencyModel)
*/
public void invalidate(DependencyModel dependencymodel) { }
/**
* Nothing to do.
* A temporal dependency is always valid.
* @param dependencymodel dependency.
* @see org.apache.felix.ipojo.util.DependencyStateListener#validate(org.apache.felix.ipojo.util.DependencyModel)
*/
public void validate(DependencyModel dependencymodel) { }
}