ReactiveStreamsJMXTest.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.component.reactive.streams;

import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import javax.management.AttributeValueExp;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.Query;
import javax.management.QueryExp;
import javax.management.StringValueExp;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.TabularData;

import org.apache.camel.RoutesBuilder;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.reactive.streams.api.CamelReactiveStreams;
import org.apache.camel.component.reactive.streams.api.CamelReactiveStreamsService;
import org.apache.camel.test.junit4.CamelTestSupport;
import org.junit.Test;

import reactor.core.publisher.Flux;

/**
 * Test exposed services on JMX.
 */
public class ReactiveStreamsJMXTest extends CamelTestSupport {

    @Test
    public void testJmxExposedService() throws Exception {
        MBeanServer mbeanServer = getMBeanServer();
        ObjectName rxService = getReactiveStreamsServiceName(mbeanServer);

        Map<String, Object> subdata = getValues(mbeanServer, rxService, "camelSubscribers", 0);
        assertEquals("unbounded", subdata.get("name"));
        assertEquals(0L, subdata.get("inflight"));
        assertEquals(0L, subdata.get("requested"));

        Map<String, Object> pubdata = getValues(mbeanServer, rxService, "camelPublishers", 0);
        assertEquals("strings", pubdata.get("name"));
        assertEquals(1, pubdata.get("subscribers"));


        TabularData subTd0 = (TabularData) pubdata.get("subscriptions");
        assertEquals(1, subTd0.values().size());

        // Create another subscriber
        CamelReactiveStreamsService rxCamel = CamelReactiveStreams.get(context());
        Flux.from(rxCamel.fromStream("strings"))
                .subscribe();

        pubdata = getValues(mbeanServer, rxService, "camelPublishers", 0);
        TabularData subTd = (TabularData) pubdata.get("subscriptions");
        assertEquals(2, subTd.values().size());
        Map<String, Object> subscriptions = getValues(subTd, 1);
        assertEquals("BUFFER", subscriptions.get("back pressure"));
    }

    private Map<String, Object> getValues(MBeanServer mbeanServer, ObjectName rxService, String name, int index) throws Exception {
        TabularData td = (TabularData) mbeanServer.invoke(rxService, name, null, null);
        return getValues(td, index);
    }

    private Map<String, Object> getValues(TabularData td, int index) {
        assertNotNull(td);
        assertTrue(td.values().size() > index);
        CompositeData data = (CompositeData) new LinkedList<>(td.values()).get(index);
        assertNotNull(data);
        Map<String, Object> res = new HashMap<>();
        for (String key : data.getCompositeType().keySet()) {
            res.put(key, data.get(key));
        }
        return res;
    }

    private MBeanServer getMBeanServer() {
        return context.getManagementStrategy().getManagementAgent().getMBeanServer();
    }

    private ObjectName getReactiveStreamsServiceName(MBeanServer mbeanServer) throws Exception {
        ObjectName on = ObjectName.getInstance("org.apache.camel:type=services,*");
        QueryExp queryExp = Query.match(new AttributeValueExp("ServiceType"), new StringValueExp("DefaultCamelReactiveStreamsService"));
        Set<ObjectName> names = mbeanServer.queryNames(on, queryExp);
        assertEquals(1, names.size());
        return names.iterator().next();
    }

    @Override
    protected boolean useJmx() {
        return true;
    }

    @Override
    protected RoutesBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {
            @Override
            public void configure() throws Exception {
                from("reactive-streams:unbounded?maxInflightExchanges=-1")
                        .delayer(1)
                        .to("mock:unbounded-endpoint");

                from("timer:tick")
                        .setBody().simple("Hello world ${header.CamelTimerCounter}")
                        .to("reactive-streams:strings");


                CamelReactiveStreamsService rxCamel = CamelReactiveStreams.get(getContext());

                Flux.from(rxCamel.fromStream("strings", String.class))
                        .doOnNext(System.out::println)
                        .subscribe();
            }
        };
    }
}