camel-2.8.x/camel-core/src/test/java/org/apache/camel/processor/SplitAggregateInOutTest.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.processor;

import org.apache.camel.ContextTestSupport;
import org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.mock.MockEndpoint;
import org.apache.camel.impl.JndiRegistry;
import org.apache.camel.processor.aggregate.AggregationStrategy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @version 
 */
public class SplitAggregateInOutTest extends ContextTestSupport {

    private static final Logger LOG = LoggerFactory.getLogger(SplitAggregateInOutTest.class);

    private String expectedBody = "Response[(id=1,item=A);(id=2,item=B);(id=3,item=C)]";

    public void testSplitAndAggregateInOut() throws Exception {
        MockEndpoint mock = getMockEndpoint("mock:result");
        mock.expectedBodiesReceived(expectedBody);

        // use requestBody as its InOut
        Object out = template.requestBody("direct:start", "A@B@C");
        assertEquals(expectedBody, out);
        LOG.debug("Response to caller: " + out);

        assertMockEndpointsSatisfied();
    }

    @Override
    protected JndiRegistry createRegistry() throws Exception {
        JndiRegistry jndi = super.createRegistry();
        jndi.bind("MyOrderService", new MyOrderService());
        return jndi;
    }

    @Override
    protected RouteBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {
            @Override
            public void configure() throws Exception {
                // START SNIPPET: e1
                // this routes starts from the direct:start endpoint
                // the body is then splitted based on @ separator
                // the splitter in Camel supports InOut as well and for that we need
                // to be able to aggregate what response we need to send back, so we provide our
                // own strategy with the class MyOrderStrategy.
                from("direct:start")
                    .split(body().tokenize("@"), new MyOrderStrategy())
                        // each splitted message is then send to this bean where we can process it
                        .to("bean:MyOrderService?method=handleOrder")
                        // this is important to end the splitter route as we do not want to do more routing
                        // on each splitted message
                    .end()
                    // after we have splitted and handled each message we want to send a single combined
                    // response back to the original caller, so we let this bean build it for us
                    // this bean will receive the result of the aggregate strategy: MyOrderStrategy
                    .to("bean:MyOrderService?method=buildCombinedResponse")
                // END SNIPPET: e1
                    .to("mock:result");
            }
        };
    }

    // START SNIPPET: e2
    public static class MyOrderService {

        private static int counter;

        /**
         * We just handle the order by returning a id line for the order
         */
        public String handleOrder(String line) {
            LOG.debug("HandleOrder: " + line);
            return "(id=" + ++counter + ",item=" + line + ")";
        }

        /**
         * We use the same bean for building the combined response to send
         * back to the original caller
         */
        public String buildCombinedResponse(String line) {
            LOG.debug("BuildCombinedResponse: " + line);
            return "Response[" + line + "]";
        }
    }
    // END SNIPPET: e2

    // START SNIPPET: e3
    /**
     * This is our own order aggregation strategy where we can control
     * how each splitted message should be combined. As we do not want to
     * loos any message we copy from the new to the old to preserve the
     * order lines as long we process them
     */
    public static class MyOrderStrategy implements AggregationStrategy {

        public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
            // put order together in old exchange by adding the order from new exchange

            if (oldExchange == null) {
                // the first time we aggregate we only have the new exchange,
                // so we just return it
                return newExchange;
            }

            String orders = oldExchange.getIn().getBody(String.class);
            String newLine = newExchange.getIn().getBody(String.class);

            LOG.debug("Aggregate old orders: " + orders);
            LOG.debug("Aggregate new order: " + newLine);

            // put orders together separating by semi colon
            orders = orders + ";" + newLine;
            // put combined order back on old to preserve it
            oldExchange.getIn().setBody(orders);

            // return old as this is the one that has all the orders gathered until now
            return oldExchange;
        }
    }
    // END SNIPPET: e3

}