Spring Testing

Testing is a crucial part of any development or integration work. The Spring Framework offers a number of features that makes it easy to test while using Spring for Inversion of Control which works with JUnit 3.x or JUnit 4.x.

We can use Spring for IoC and the Camel Mock and Test endpoints to create sophisticated integration/unit tests that are easy to run and debug inside your IDE. There are three supported approaches for testing with Spring in Camel.

Name Testing Frameworks Supported Description Required Camel Test Dependencies

CamelSpringTestSupport

* JUnit 3.x (deprecated) * JUnit 4.x

Provided by org.apache.camel.test.CamelSpringTestSupport and org.apache.camel.test.junit4.CamelSpringTestSupport. These base classes provide feature parity with the simple CamelTestSupport classes from Camel Test but do not support Spring annotations on the test class such as @Autowired, @DirtiesContext, and @ContextConfiguration.

* JUnit 3.x (deprecated) - camel-test-spring * JUnit 4.x - camel-test-spring

Plain Spring Test

* JUnit 3.x * JUnit 4.x

Extend the abstract base classes (org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests, org.springframework.test.context.junit38.AbstractJUnit4SpringContextTests, etc.) provided in Spring Test or use the Spring Test JUnit4 runner. These approaches support both the Camel annotations and Spring annotations, but do not have feature parity with org.apache.camel.test.CamelTestSupport and org.apache.camel.test.junit4.CamelTestSupport.

* JUnit 3.x (deprecated) - None * JUnit 4.x - None

Camel Enhanced Spring Test

* JUnit 4.x - Camel 2.10

Use the org.apache.camel.test.junit4.CamelSpringJUnit4ClassRunner runner with the @RunWith annotation to enable feature parity with org.apache.camel.test.CamelTestSupport and org.apache.camel.test.junit4.CamelTestSupport and also support the full suite of Spring Test annotations such as @Autowired, @DirtiesContext, and @ContextConfiguration.

* JUnit 3.x (deprecated) - camel-test-spring * JUnit 4.x - camel-test-spring

CamelSpringTestSupport

org.apache.camel.test.CamelSpringTestSupport and org.apache.camel.test.junit4.CamelSpringTestSupport extend their non-Spring aware counterparts (org.apache.camel.test.CamelTestSupport and org.apache.camel.test.junit4.CamelTestSupport) and deliver integration with Spring into your test classes. Instead of instantiating the CamelContext and routes programmatically, these classes rely on a Spring context to wire the needed components together. If your test extends one of these classes, you must provide the Spring context by implementing the following method.

protected abstract AbstractApplicationContext createApplicationContext();

You are responsible for the instantiation of the Spring context in the method implementation. All of the features available in the non-Spring aware counterparts from Camel Test are available in your test.

Plain Spring Test

In this approach, your test classes directly inherit from the Spring Test abstract test classes or use the JUnit 4.x test runner provided in Spring Test. This approach supports dependency injection into your test class and the full suite of Spring Test annotations but does not support the features provided by the CamelSpringTestSupport classes.

Plain Spring Test using JUnit 3.x with XML Config Example

Here is a simple unit test using JUnit 3.x support from Spring Test using XML Config.

Notice that we use @DirtiesContext on the test methods to force Spring Testing to automatically reload the CamelContext after each test method - this ensures that the tests don’t clash with each other (e.g. one test method sending to an endpoint that is then reused in another test method).

Also notice the use of @ContextConfiguration to indicate that by default we should look for the FilterTest-context.xml on the classpath to configure the test case which looks like this

This test will load a Spring XML configuration file calledFilterTest-context.xml from the classpath in the same package structure as the FilterTest class and initialize it along with any Camel routes we define inside it, then inject theCamelContextinstance into our test case.

For instance, like this maven folder layout:

src/test/java/org/apache/camel/spring/patterns/FilterTest.java
src/test/resources/org/apache/camel/spring/patterns/FilterTest-context.xml

Plain Spring Test using JUnit 4.x with Java Config Example

You can completely avoid using an XML configuration file by using Spring Java Config. Here is a unit test using JUnit 4.x support from Spring Test using Java Config.

This is similar to the XML Config example above except that there is no XML file and instead the nested ContextConfig class does all of the configuration; so your entire test case is contained in a single Java class. We currently have to reference by class name this class in the @ContextConfiguration which is a bit ugly. Please vote for SJC-238 to address this and make Spring Test work more cleanly with Spring JavaConfig.

Plain Spring Test using JUnit 4.0.x Runner with XML Config

You can avoid extending Spring classes by using the SpringJUnit4ClassRunner provided by Spring Test. This custom JUnit runner means you are free to choose your own class hierarchy while retaining all the capabilities of Spring Test.

INFO:This is for Spring 4.0.x. If you use Spring 4.1 or newer, then see the next section.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class MyCamelTest {

    @Autowired
    protected CamelContext camelContext;

    @EndpointInject("mock:foo")
    protected MockEndpoint foo;


    @Test
    @DirtiesContext
    public void testMocksAreValid() throws Exception {
        ...

        foo.message(0).header("bar").isEqualTo("ABC");

        MockEndpoint.assertIsSatisfied(camelContext);
    }
}

Plain Spring Test using JUnit 4.1.x Runner with XML Config

You can avoid extending Spring classes by using the SpringJUnit4ClassRunner provided by Spring Test. This custom JUnit runner means you are free to choose your own class hierarchy while retaining all the capabilities of Spring Test.

INFO:When using Spring 4.1 onwards, you need to use the @BootstrapWith annotation to configure it to use Camel testing, as shown below.

@RunWith(CamelSpringJUnit4ClassRunner.class)
@BootstrapWith(CamelTestContextBootstrapper.class)
@ContextConfiguration
public class MyCamelTest {

    @Autowired
    protected CamelContext camelContext;

    @EndpointInject("mock:foo")
    protected MockEndpoint foo;


    @Test
    @DirtiesContext
    public void testMocksAreValid() throws Exception {
        ...

        foo.message(0).header("bar").isEqualTo("ABC");

        MockEndpoint.assertIsSatisfied(camelContext);
    }
}

Camel Enhanced Spring Test

Using org.apache.camel.test.junit4.CamelSpringJUnit4ClassRunner runner with the @RunWith annotation provides the full feature set of Spring Test with support for the feature set provided in the CamelTestSupport classes. A number of Camel specific annotations have been developed in order to provide for declarative manipulation of the Camel context(s) involved in the test. These annotations free your test classes from having to inherit from the CamelSpringTestSupport classes and also reduce the amount of code required to customize the tests.

Annotation Class Applies To Description Default Behavior If Not Present Default Behavior If Present

org.apache.camel.test.spring.DisableJmx

Class

Indicates if JMX should be globally disabled in the CamelContexts that are bootstrapped during the test through the use of Spring Test loaded application contexts.

JMX is disabled

JMX is disabled

org.apache.camel.test.spring.ExcludeRoutes

Class

Indicates if certain route builder classes should be excluded from discovery. Initializes a org.apache.camel.spi.PackageScanClassResolver to exclude a set of given classes from being resolved. Typically this is used at test time to exclude certain routes, which might otherwise be just noisy, from being discovered and initialized.

Not enabled and no routes are excluded

No routes are excluded

org.apache.camel.test.spring.MockEndpoints

Class

Triggers the auto-mocking of endpoints whose URIs match the provided filter. The default filter is "*" which matches all endpoints. See org.apache.camel.impl.InterceptSendToMockEndpointStrategy for more details on the registration of the mock endpoints.

Not enabled

All endpoints are sniffed and recorded in a mock endpoint.

org.apache.camel.test.spring.MockEndpointsAndSkip

Class

Triggers the auto-mocking of endpoints whose URIs match the provided filter. The default filter is "*", which matches all endpoints. See org.apache.camel.impl.InterceptSendToMockEndpointStrategy for more details on the registration of the mock endpoints. This annotation will also skip sending the message to matched endpoints as well.

Not enabled

All endpoints are sniffed and recorded in a mock endpoint. The original endpoint is not invoked.

org.apache.camel.test.spring.ProvidesBreakpoint

Method

Indicates that the annotated method returns an org.apache.camel.spi.Breakpoint for use in the test. Useful for intercepting traffic to all endpoints or simply for setting a break point in an IDE for debugging. The method must be public, static, take no arguments, and return org.apache.camel.spi.Breakpoint.

N/A

The returned Breakpoint is registered in the CamelContext(s)

org.apache.camel.test.spring.ShutdownTimeout

Class

Indicates to set the shutdown timeout of all CamelContexts instantiated through the use of Spring Test loaded application contexts. If no annotation is used, the timeout is automatically reduced to 10 seconds by the test framework.

10 seconds

10 seconds

org.apache.camel.test.spring.UseAdviceWith

Class

Indicates the use of adviceWith() within the test class. If a class is annotated with this annotation and UseAdviceWith#value() returns true, any CamelContexts bootstrapped during the test through the use of Spring Test loaded application contexts will not be started automatically. The test author is responsible for injecting the Camel contexts into the test and executing CamelContext#start() on them at the appropriate time after any advice has been applied to the routes in the CamelContext(s).

CamelContexts do not automatically start.

CamelContexts do not automatically start.

org.apache.camel.test.spring.UseOverridePropertiesWithPropertiesComponent

Method

*Camel 2.16:*Indicates that the annotated method returns a java.util.Properties for use in the test, and that those properties override any existing properties configured on the PropertiesComponent

Override properties

The following example illustrates the use of the @MockEndpoints annotation in order to setup mock endpoints as interceptors on all endpoints using the Camel Log component and the @DisableJmx annotation to enable JMX which is disabled during tests by default. Note that we still use the @DirtiesContext annotation to ensure that the CamelContext, routes, and mock endpoints are reinitialized between test methods.

@RunWith(CamelSpringJUnit4ClassRunner.class)
@BootstrapWith(CamelTestContextBootstrapper.class)
@ContextConfiguration
@DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD)
@MockEndpoints("log:*")
@DisableJmx(false)
public class CamelSpringJUnit4ClassRunnerPlainTest {

    @Autowired
    protected CamelContext camelContext2;

    protected MockEndpoint mockB;

    @EndpointInject(value = "mock:c", context = "camelContext2")
    protected MockEndpoint mockC;

    @Produce(uri = "direct:start2", context = "camelContext2")
    protected ProducerTemplate start2;

    @EndpointInject(value = "mock:log:org.apache.camel.test.junit4.spring", context = "camelContext2")
    protected MockEndpoint mockLog;

    @Test
    public void testPositive() throws Exception {

        mockC.expectedBodiesReceived("David");
        mockLog.expectedBodiesReceived("Hello David");

        start2.sendBody("David");

        MockEndpoint.assertIsSatisfied(camelContext);
    }

Adding more Mock expectations

If you wish to programmatically add any new assertions to your test you can easily do so with the following. Notice how we use @EndpointInject to inject a Camel endpoint into our code then the Mock API to add an expectation on a specific message.

@ContextConfiguration
public class MyCamelTest extends AbstractJUnit38SpringContextTests {

    @Autowired
    protected CamelContext camelContext;

    @EndpointInject("mock:foo")
    protected MockEndpoint foo;

    public void testMocksAreValid() throws Exception {
        // lets add more expectations
        foo.message(0).header("bar").isEqualTo("ABC");

        MockEndpoint.assertIsSatisfied(camelContext);
    }
}

Further processing the received messages

Sometimes once a Mock endpoint has received some messages you want to then process them further to add further assertions that your test case worked as you expect.

So you can then process the received message exchanges if you like…​

@ContextConfiguration
public class MyCamelTest extends AbstractJUnit38SpringContextTests {

    @Autowired
    protected CamelContext camelContext;

    @EndpointInject("mock:foo")
    protected MockEndpoint foo;

    public void testMocksAreValid() throws Exception {
        // lets add more expectations...

        MockEndpoint.assertIsSatisfied(camelContext);

        // now lets do some further assertions
        List<Exchange> list = foo.getReceivedExchanges();
        for (Exchange exchange : list) {
            Message in = exchange.getIn();
            ...
        }
    }
}

Sending and receiving messages

It might be that the Enterprise Integration Patterns you have defined in either Spring XML or using the Java DSL do all of the sending and receiving and you might just work with the Mock endpoints as described above. However sometimes in a test case its useful to explicitly send or receive messages directly.

To send or receive messages you should use the Bean Integration mechanism. For example to send messages inject a ProducerTemplate using the @EndpointInject annotation then call the various send methods on this object to send a message to an endpoint. To consume messages use the @MessageDriven annotation on a method to have the method invoked when a message is received.

public class Foo {
  @EndpointInject(uri="activemq:foo.bar")
  ProducerTemplate producer;

  public void doSomething() {
    // lets send a message!
    producer.sendBody("<hello>world!</hello>");
  }

  // lets consume messages from the 'cheese' queue
  @MessageDriven(uri="activemq:cheese")
  public void onCheese(String name) {
    ...
  }
}
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