FileRollbackOnCompletionTest.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 java.io.File;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.apache.camel.CamelExecutionException;
import org.apache.camel.ContextTestSupport;
import org.apache.camel.Exchange;
import org.apache.camel.Header;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.spi.Synchronization;
import org.apache.camel.util.FileUtil;

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

    private static final CountDownLatch LATCH = new CountDownLatch(1);

    public static final class FileRollback implements Synchronization {

        public void onComplete(Exchange exchange) {
            // this method is invoked when the Exchange completed with no failure
        }

        public void onFailure(Exchange exchange) {
            // delete the file
            String name = exchange.getIn().getHeader(Exchange.FILE_NAME_PRODUCED, String.class);
            FileUtil.deleteFile(new File(name));

            // signal we have deleted the file
            LATCH.countDown();
        }

    }

    public static final class OrderService {

        public String createMail(String order) throws Exception {
            return "Order confirmed: " + order;
        }

        public void sendMail(String body, @Header("to") String to) {
            // simulate fatal error if we refer to a special no
            if (to.equals("FATAL")) {
                throw new IllegalArgumentException("Simulated fatal error");
            }
        }

    }

    @Override
    public void setUp() throws Exception {
        deleteDirectory("target/mail/backup");
        super.setUp();
    }

    public void testOk() throws Exception {
        template.sendBodyAndHeader("direct:confirm", "bumper", "to", "someone@somewhere.org");

        File file = new File("target/mail/backup/");
        String[] files = file.list();
        assertEquals("There should be one file", 1, files.length);
    }

    public void testRollback() throws Exception {
        try {
            template.sendBodyAndHeader("direct:confirm", "bumper", "to", "FATAL");
            fail("Should have thrown an exception");
        } catch (CamelExecutionException e) {
            assertIsInstanceOf(IllegalArgumentException.class, e.getCause());
            assertEquals("Simulated fatal error", e.getCause().getMessage());
        }

        oneExchangeDone.matchesMockWaitTime();

        // onCompletion is async so we gotta wait a bit for the file to be deleted
        assertTrue("Should countdown the latch", LATCH.await(5, TimeUnit.SECONDS));

        File file = new File("target/mail/backup/");
        String[] files = file.list();
        assertEquals("There should be no files", 0, files.length);
    }

    @Override
    protected RouteBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {
            @Override
            public void configure() throws Exception {
                from("direct:confirm")
                    // use a route scoped onCompletion to be executed when the Exchange failed
                    .onCompletion().onFailureOnly()
                        // and call the onFailure method on this bean
                        .bean(FileRollback.class, "onFailure")
                        // must use end to denote the end of the onCompletion route
                    .end()
                    // here starts the regular route
                    .bean(OrderService.class, "createMail")
                    .log("Saving mail backup file")
                    .to("file:target/mail/backup")
                    .log("Trying to send mail to ${header.to}")
                    .bean(OrderService.class, "sendMail")
                    .log("Mail send to ${header.to}");
            }
        };
    }

}