/*
* 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.ode.bpel.engine.extvar;
import java.util.HashMap;
import java.util.Map;
import javax.xml.namespace.QName;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ode.bpel.engine.BpelProcess;
import org.apache.ode.bpel.iapi.BpelEngineException;
import org.apache.ode.bpel.o.OBase;
import org.apache.ode.bpel.o.OElementVarType;
import org.apache.ode.bpel.o.OProcess;
import org.apache.ode.bpel.o.OScope;
import org.apache.ode.bpel.o.OScope.Variable;
import org.apache.ode.bpel.evar.ExternalVariableModule;
import org.apache.ode.bpel.evar.ExternalVariableModuleException;
import org.apache.ode.bpel.evar.ExternalVariableModule.Locator;
import org.apache.ode.bpel.evar.ExternalVariableModule.Value;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
/**
* Manager for external variable instances; used by {@link BpelProcess} to manage external variables.
*
* @author Maciej Szefler <mszefler at gmail dot com>
*
*/
public class ExternalVariableManager {
private static final Log __log = LogFactory.getLog(ExternalVariableManager.class);
/** Mapping of engine names to engine. */
private Map<QName, ExternalVariableModule> _engines;
/** Mapping between external variable identifiers and the engines that are used to serve them up. */
private final Map<String, EVar> _externalVariables = new HashMap<String, EVar>();
/** The configuration. */
private final ExternalVariableConf _extVarConf;
/** Process ID */
private QName _pid;
public ExternalVariableManager(QName pid,
ExternalVariableConf evconf,
Map<QName, ExternalVariableModule> engines,
OProcess oprocess)
throws BpelEngineException {
_pid = pid;
_extVarConf = evconf;
_engines = engines;
boolean fatal = false;
// Walk the configuration and find all the variabless.
for (ExternalVariableConf.Variable var : _extVarConf.getVariables()) {
EVar evar = new EVar(var.extVariableId, _engines.get(var.engineQName), var.configuration);
if (evar._engine == null) {
__log.error("External variable engine \"" + var.engineQName
+ "\" referenced by external variable \"" + var.extVariableId
+ "\" not registered.");
fatal = true;
continue;
}
try {
evar._engine.configure(_pid, evar._extVarId, evar._config);
} catch (ExternalVariableModuleException eve) {
__log.error("External variable subsystem configuration error.", eve);
throw new BpelEngineException("External variable subsystem configuration error.",eve);
}
if (_externalVariables.containsKey(var.extVariableId)) {
__log.warn("Duplicate external variable configuration for \"" + var.extVariableId + "\" will be ignored!");
}
_externalVariables.put(var.extVariableId, evar);
}
// Walk down the process definition looking for any external variables.
for (OBase child : oprocess.getChildren()) {
if (!(child instanceof OScope))
continue;
OScope oscope = (OScope) child;
for (OScope.Variable var : oscope.variables.values()) {
if (var.extVar == null)
continue;
EVar evar = _externalVariables.get(var.extVar.externalVariableId);
if (evar == null) {
__log.error("The \"" + oscope.name + "\" scope declared an unknown external variable \""
+ var.extVar.externalVariableId + "\"; check the deployment descriptor.");
fatal = true;
continue;
}
}
}
if (fatal) {
String errmsg = "Error initializing external variables. See log for details.";
__log.error(errmsg);
throw new BpelEngineException(errmsg);
}
}
/**
* Read an external variable.
*/
public Value read(Variable variable, Node reference, Long iid) throws ExternalVariableModuleException{
EVar evar = _externalVariables.get(variable.extVar.externalVariableId);
if (evar == null) {
// Should not happen if constructor is working.
throw new BpelEngineException("InternalError: reference to unknown external variable " + variable.extVar.externalVariableId);
}
Locator locator = new Locator(variable.extVar.externalVariableId, _pid,iid, reference);
Value newval;
newval = evar._engine.readValue(((OElementVarType) variable.type).elementType, locator );
if (newval == null)
return null;
return newval;
}
public Value write(Variable variable, Node reference, Node val, Long iid) throws ExternalVariableModuleException {
EVar evar = _externalVariables.get(variable.extVar.externalVariableId);
if (evar == null) {
// Should not happen if constructor is working.
throw new BpelEngineException("InternalError: reference to unknown external variable " + variable.extVar.externalVariableId);
}
Locator locator = new Locator(variable.extVar.externalVariableId,_pid,iid,reference);
Value newval = new Value(locator,val,null);
newval = evar._engine.writeValue(((OElementVarType) variable.type).elementType, newval);
return newval;
}
static final class EVar {
final ExternalVariableModule _engine;
final Element _config;
final String _extVarId;
EVar(String id, ExternalVariableModule engine, Element config) {
_extVarId = id;
_engine = engine;
_config = config;
}
}
}