ProxyConnector.java

/**
 * Licensed to the Austrian Association for Software Tool Integration (AASTI)
 * under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership. The AASTI 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.openengsb.core.services.internal.virtual;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.openengsb.core.api.AliveState;
import org.openengsb.core.api.Connector;
import org.openengsb.core.api.remote.MethodCall;
import org.openengsb.core.api.remote.MethodResult;
import org.openengsb.core.api.remote.OutgoingPortUtilService;
import org.openengsb.core.common.VirtualConnector;
import org.openengsb.core.ekb.api.TransformationEngine;
import org.openengsb.core.services.internal.TransformationHandler;

/**
 * Representation of a connector that forwards all method-calls to a remote connector. Communication is done using a
 * port-implementation (like jms+json)
 */
public class ProxyConnector extends VirtualConnector {

    private String portId;
    private String destination;
    private final Map<String, String> metadata = new HashMap<String, String>();
    private String domainId;
    private String connectorId;

    private OutgoingPortUtilService portUtil;
    private ProxyRegistration registration;

    private TransformationEngine transformationEngine;
    private Class<?> connectorInterface;

    public ProxyConnector(String instanceId, OutgoingPortUtilService portUtil, ProxyRegistration registration) {
        super(instanceId);
        this.portUtil = portUtil;
        this.registration = registration;
    }

    @Override
    public Object doInvoke(Object proxy, Method method, Object[] args) throws Throwable {
        if (method.getDeclaringClass().equals(Connector.class)) {
            return this.getClass().getMethod(method.getName(), method.getParameterTypes()).invoke(this, args);
        }
        TransformationHandler transformationHandler = TransformationHandler
                .newTransformationHandler(transformationEngine, method, connectorInterface);
        transformationHandler.getTargetMethod();
        Method targetMethod = transformationHandler.getTargetMethod();
        Object[] targetArgs = transformationHandler.transformArguments(args);
        MethodCall methodCall = new MethodCall(targetMethod, targetArgs, metadata);

        if (!registration.isRegistered()) {
            if (targetMethod.getName().equals("getAliveState")) {
                return AliveState.OFFLINE;
            }
            throw new IllegalArgumentException("not registered");
        }

        MethodResult callResult =
                portUtil.sendMethodCallWithResult(registration.getPortId(), registration.getDestination(), methodCall);
        switch (callResult.getType()) {
            case Object:
                Object result = callResult.getArg();
                return transformationHandler.transformResult(result);
            case Void:
                return null;
            case Exception:
                throw new RuntimeException(callResult.getArg().toString());
            default:
                throw new IllegalStateException("Return Type has to be either Void, Object or Exception");
        }
    }

    public final void setPortId(String id) {
        portId = id;
    }

    public final void setDestination(String destination) {
        this.destination = destination;
    }

    public void addMetadata(String key, String value) {
        metadata.put(key, value);
    }

    public final void setOutgoingPortUtilService(OutgoingPortUtilService portUtil) {
        this.portUtil = portUtil;
    }

    public final String getPortId() {
        return portId;
    }

    public final String getDestination() {
        return destination;
    }

    public final OutgoingPortUtilService getCallRouter() {
        return portUtil;
    }

    public String getDomainId() {
        return domainId;
    }

    public void setDomainId(String domainId) {
        this.domainId = domainId;
    }

    public String getConnectorId() {
        return connectorId;
    }

    public void setConnectorId(String connectorId) {
        this.connectorId = connectorId;
    }

    public void setConnectorInterface(Class<?> connectorInterface) {
        this.connectorInterface = connectorInterface;
    }

    public void setTransformationEngine(TransformationEngine transformationEngine) {
        this.transformationEngine = transformationEngine;
    }
}