core/camel-core/src/test/java/org/apache/camel/impl/ScheduledPollConsumerTest.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.impl;

import java.util.concurrent.atomic.AtomicInteger;

import org.apache.camel.Consumer;
import org.apache.camel.ContextTestSupport;
import org.apache.camel.Endpoint;
import org.apache.camel.spi.PollingConsumerPollStrategy;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

public class ScheduledPollConsumerTest extends ContextTestSupport {

    private static boolean rollback;
    private static String event = "";

    @Test
    public void testExceptionOnPollAndCanStartAgain() {
        final Exception expectedException = new Exception("Hello, I should be thrown on shutdown only!");
        final Endpoint endpoint = getMockEndpoint("mock:foo");
        MockScheduledPollConsumer consumer = new MockScheduledPollConsumer(endpoint, expectedException);

        consumer.setPollStrategy(new PollingConsumerPollStrategy() {
            public boolean begin(Consumer consumer, Endpoint endpoint) {
                return true;
            }

            public void commit(Consumer consumer, Endpoint endpoint, int polledMessages) {
            }

            public boolean rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception e) {
                if (e == expectedException) {
                    rollback = true;
                }
                return false;
            }
        });

        consumer.start();
        // poll that throws an exception
        consumer.run();
        consumer.stop();

        assertTrue(rollback, "Should have rollback");

        // prepare for 2nd run but this time it should not thrown an exception
        // on poll
        rollback = false;
        consumer.setExceptionToThrowOnPoll(null);
        // start it again and we should be able to run
        consumer.start();
        consumer.run();
        // should be able to stop with no problem
        consumer.stop();

        assertFalse(rollback, "Should not have rollback");
    }

    @Test
    public void testRetryAtMostThreeTimes() {
        final AtomicInteger counter = new AtomicInteger();
        event = "";

        final Exception expectedException = new Exception("Hello, I should be thrown on shutdown only!");
        final Endpoint endpoint = getMockEndpoint("mock:foo");
        MockScheduledPollConsumer consumer = new MockScheduledPollConsumer(endpoint, expectedException);

        consumer.setPollStrategy(new PollingConsumerPollStrategy() {
            public boolean begin(Consumer consumer, Endpoint endpoint) {
                return true;
            }

            public void commit(Consumer consumer, Endpoint endpoint, int polledMessages) {
                event += "commit";
            }

            public boolean rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception e) {
                event += "rollback";
                int cnt = counter.incrementAndGet();
                if (cnt <= 3) {
                    return true;
                }
                return false;
            }
        });

        consumer.setUseFixedDelay(true);
        consumer.setDelay(60000);
        consumer.start();
        // poll that throws an exception
        consumer.run();
        consumer.stop();

        // 3 retries + 1 last failed attempt when we give up
        assertEquals(4, counter.get());
        assertEquals("rollbackrollbackrollbackrollback", event);
    }

    @Test
    public void testNoExceptionOnPoll() {
        final Endpoint endpoint = getMockEndpoint("mock:foo");
        MockScheduledPollConsumer consumer = new MockScheduledPollConsumer(endpoint, null);
        consumer.start();
        consumer.run();
        consumer.stop();
    }

}