camel-2.8.x/camel-core/src/main/java/org/apache/camel/model/InterceptSendToEndpointDefinition.java

/**
 * 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.camel.model;

import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;

import org.apache.camel.Endpoint;
import org.apache.camel.Predicate;
import org.apache.camel.Processor;
import org.apache.camel.impl.InterceptSendToEndpoint;
import org.apache.camel.processor.InterceptEndpointProcessor;
import org.apache.camel.spi.EndpointStrategy;
import org.apache.camel.spi.RouteContext;
import org.apache.camel.util.EndpointHelper;

/**
 * Represents an XML <interceptToEndpoint/> element
 *
 * @version 
 */
@XmlRootElement(name = "interceptToEndpoint")
@XmlAccessorType(XmlAccessType.FIELD)
public class InterceptSendToEndpointDefinition extends OutputDefinition<InterceptSendToEndpointDefinition> {

    // TODO: Support lookup endpoint by ref (requires a bit more work)

    // TODO: interceptSendToEndpoint needs to proxy the endpoints at very first
    // so when other processors uses an endpoint its already proxied, see workaround in SendProcessor
    // needed when we haven't proxied beforehand. This requires some work in the route builder in Camel
    // to implement so that should be a part of a bigger rework/improvement in the future

    @XmlAttribute(required = true)
    private String uri;
    @XmlAttribute
    private Boolean skipSendToOriginalEndpoint;

    public InterceptSendToEndpointDefinition() {
    }

    public InterceptSendToEndpointDefinition(String uri) {
        this.uri = uri;
    }

    @Override
    public String toString() {
        return "InterceptSendToEndpoint[" + uri + " -> " + getOutputs() + "]";
    }

    @Override
    public String getShortName() {
        return "interceptSendToEndpoint";
    }

    @Override
    public String getLabel() {
        return "interceptEndpoint";
    }

    @Override
    public boolean isAbstract() {
        return true;
    }

    @Override
    public Processor createProcessor(RouteContext routeContext) throws Exception {
        // create the detour
        final Processor detour = this.createChildProcessor(routeContext, true);

        // register endpoint callback so we can proxy the endpoint
        routeContext.getCamelContext().addRegisterEndpointCallback(new EndpointStrategy() {
            public Endpoint registerEndpoint(String uri, Endpoint endpoint) {
                
                if (endpoint instanceof InterceptSendToEndpoint) {
                    // endpoint already decorated
                    return endpoint;
                } else if (getUri() == null || EndpointHelper.matchEndpoint(uri, getUri())) {
                    // only proxy if the uri is matched decorate endpoint with our proxy
                    // should be false by default
                    boolean skip = getSkipSendToOriginalEndpoint() != null ? getSkipSendToOriginalEndpoint() : false;
                    InterceptSendToEndpoint proxy = new InterceptSendToEndpoint(endpoint, skip);
                    proxy.setDetour(detour);
                    return proxy;
                } else {
                    // no proxy so return regular endpoint
                    return endpoint;
                }
            }
        });


        // remove the original intercepted route from the outputs as we do not intercept as the regular interceptor
        // instead we use the proxy endpoints producer do the triggering. That is we trigger when someone sends
        // an exchange to the endpoint, see InterceptSendToEndpoint for details.
        RouteDefinition route = routeContext.getRoute();
        List<ProcessorDefinition> outputs = route.getOutputs();
        outputs.remove(this);

        return new InterceptEndpointProcessor(uri, detour);
    }

    /**
     * Applies this interceptor only if the given predicate is true
     *
     * @param predicate  the predicate
     * @return the builder
     */
    public ChoiceDefinition when(Predicate predicate) {
        return choice().when(predicate);
    }

    /**
     * Skip sending the {@link org.apache.camel.Exchange} to the original intended endpoint
     *
     * @return the builder
     */
    public InterceptSendToEndpointDefinition skipSendToOriginalEndpoint() {
        setSkipSendToOriginalEndpoint(Boolean.TRUE);
        return this;
    }

    /**
     * This method is <b>only</b> for handling some post configuration
     * that is needed from the Spring DSL side as JAXB does not invoke the fluent
     * builders, so we need to manually handle this afterwards, and since this is
     * an interceptor it has to do a bit of magic logic to fixup to handle predicates
     * with or without proceed/stop set as well.
     */
    public void afterPropertiesSet() {
        // okay the intercept endpoint works a bit differently than the regular interceptors
        // so we must fix the route definition yet again

        if (getOutputs().size() == 0) {
            // no outputs
            return;
        }

        ProcessorDefinition first = getOutputs().get(0);
        if (first instanceof WhenDefinition) {
            WhenDefinition when = (WhenDefinition) first;
            // move this outputs to the when, expect the first one
            // as the first one is the interceptor itself
            for (int i = 1; i < outputs.size(); i++) {
                ProcessorDefinition out = outputs.get(i);
                when.addOutput(out);
            }
            // remove the moved from the original output, by just keeping the first one
            ProcessorDefinition keep = outputs.get(0);
            clearOutput();
            outputs.add(keep);
        }
    }

    public Boolean getSkipSendToOriginalEndpoint() {
        return skipSendToOriginalEndpoint;
    }

    public void setSkipSendToOriginalEndpoint(Boolean skipSendToOriginalEndpoint) {
        this.skipSendToOriginalEndpoint = skipSendToOriginalEndpoint;
    }

    public String getUri() {
        return uri;
    }

    public void setUri(String uri) {
        this.uri = uri;
    }
}