Camel Route - Unit Testing

This article covers the unit testing of a SpringBoot Camel Route using Junit.

Let us consider the use case of a process that moves the file from the input directory to the output directory by polling at specific timer intervals.

package com.demo.camelspringboot.route;

import org.apache.camel.builder.RouteBuilder;

import org.springframework.stereotype.Component;

@Component

public class CamelRoute extends RouteBuilder {

    @Override

    public void configure() throws Exception {

        from("{{routeStart}}")

                .log("Timer has been invoked")

                .pollEnrich("{{routeFrom}}")

                .to("{{routeTo}}");

    }

}

The route configurations are externalized and maintained in the application.yml file.

x

server:

  port: 8081

routeStart: timer:dev?period=5s

routeFrom: file:dev/input?delete=true

routeTo: file:dev/output

targetEnvironment: dev

On successful run, notice that the file is deleted from the input directory of the dev folder and copied to the output directory as per the configuration.

Rather than checking manually if the file is copied to the output directory, a more ideal approach to test is by writing Junit test cases.

Add the below dependency to the pom.xml:

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<dependency>

    <groupId>org.apache.camel</groupId>

    <artifactId>camel-test-spring</artifactId>

    <version>3.7.0</version>

    <scope>test</scope>

</dependency>

• ProducerTemplate object is used to produce the files and place in the input directory.
• @ActiveProfiles annotation can be used to activate the spring profiles. In the below example, we will use dev profile.
• @SpringBootTest annotation, Spring Boot provides a convenient way to start up an application context to be used in a test. 
• The SpringRunner provides support for loading a Spring ApplicationContext and having beans @Autowired into your test instance 

In the below example, we create the input file in the input directory and at the end of test execution, we check if the file is successfully moved to output directory:

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package com.demo.camelspringboot.route;

import org.apache.camel.Exchange;

import org.apache.camel.ProducerTemplate;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.core.env.Environment;

import org.springframework.test.context.ActiveProfiles;

import org.springframework.test.context.junit4.SpringRunner;

import java.io.File;

import static org.junit.Assert.assertTrue;

@ActiveProfiles("dev")

@SpringBootTest

@RunWith(SpringRunner.class)

public class RouteTest {

    @Autowired

    ProducerTemplate producerTemplate;

    @Autowired

    Environment environment;

    @Test

    public void testFileMovement() throws InterruptedException {

        String targetEnvironment=environment.getProperty("targetEnvironment");

        String fileContent="This is a file for "+targetEnvironment;

        String fileName=targetEnvironment+".txt";

        producerTemplate.sendBodyAndHeader(environment.getProperty("routeFrom"),fileContent, Exchange.FILE_NAME,fileName);

        Thread.sleep(5000);

        File outputFile=new File(targetEnvironment+"/output/"+fileName);

        assertTrue(outputFile.exists());

    }

}

Run the test and observe the successful execution of the test case.