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This tutorial will cover all that, plus setting up tests along the way.

Tutorial Approach

You may choose to treat this as a hands-on tutorial, and work through building the code and configuration files yourself. Each of the sections gives detailed descriptions of the steps that need to be taken to get the components and routes working in Camel, and takes you through tests to make sure they are working as expected.

But each section also links to working copies of the source and configuration files, so if you don't want the hands-on approach, you can simply review and/or download the finished files.

High-Level Diagram

Here's more or less what the integration process looks like.

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You can make up your own if you like, but here are the "off the shelf" ones:" ones. You can save yourself some time by downloading these to src/test/resources in your Maven project.

• Customer 1 (XML): input-customer1.xml
• Customer 2 (CSV): input-customer2.csv
• Customer 3 (Excel): input-customer3.xls
• Canonical Acme XML Request: canonical-acme-request.xml
• Canonical Acme XML Response: TODO

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If you're ambitions, you can write your own XSD (XML Schema) for files that look like this, and save it to src/main/xsd.

Solution: If not, you can download mine. In any case, , and save that to save it to src/main/xsd.

Generating JAXB Beans

Down the road we'll want to deal with the XML as Java POJOs. We'll take a moment now to set up those XML binding POJOs. So we'll update the Maven POM to generate JAXB beans from the XSD file.

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Start with the Customer 1 sample input. You want to create an XSLT template to generate XML like the canonical XML sample above – an invoice element with line-item elements (one per item in the original XML document). If you're especially clever, you can populate the current date and order total elements too.

Solution: My sample XSLT template isn't that smart, but it'll get you going if you don't want to write one of your own.

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1. Add dependencies on Camel-Spring, and the Spring test JAR (which will automatically bring in JUnit 3.8.x) to your POM:

   Code Block
   xml xml
   <dependency> <artifactId>camel-spring</artifactId> <groupId>org.apache.camel</groupId> <version>1.4.0</version> </dependency> <dependency> <artifactId>spring-test</artifactId> <groupId>org.springframework</groupId> <version>2.5.5</version> <scope>test</scope> </dependency>

2. Create a new unit test class in src/test/java/your-package-here, perhaps called XMLInputTest.java
3. Make the test extend Spring's AbstractJUnit38SpringContextTests class.
4. Create a Spring context configuration file in src/test/resources, perhaps called XMLInputTest-context.xml
5. In the unit test class, use the class-level @ContextConfiguration annotation to indicate that a Spring context should be loaded
   • By default, this looks for a Context configuration file called TestClassName-context.xml in a subdirectory corresponding to the package of the test class. For instance, if your test class was org.apache.camel.tutorial.XMLInputTest, it would look for org/apache/camel/tutorial/XMLInputTest-context.xml
   • To override this default, use the locations attribute on the @ContextConfiguration annotation to provide specific context file locations (starting each path with a / if you don't want it to be relative to the package directory)
6. Add a CamelContext instance variable to the test class, with the @Autowired annotation
7. Add a ProducerTemplate instance variable and a setUp method that instantiates it from the CamelContext. We'll use the ProducerTemplate later to send messages to the route.

   Code Block
   java java
   protected ProducerTemplate<Exchange> template; protected void setUp() throws Exception { super.setUp(); template = camelContext.createProducerTemplate(); }

8. Put in an empty test method just for the moment
9. Add the Spring <beans> element (including the Camel Namespace) with an empty <camelContext> element to the Spring context, like this:

   Code Block
   xml xml
   <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring-1.4.0.xsd"> <camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> </camelContext> </beans> </beans>

Test it by running mvn install and make sure there are no build errors. So far it doesn't test much; just that your project and test and source files are all organized correctly.

Solution: Your test class might look something like this:

• src/test/java/org/apache/camel/tutorial/XMLInputTest.java
• src/test/resources/XMLInputTest-context.xml (same as just above)

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Flesh Out the Unit Test

So now we're going to write a Camel route that applies the XSLT to the sample Customer 1 input file, and makes sure that some XML output comes out:

1. Save the input-customer1.xml file to src/test/resources
2. Save your XSLT file (created in the previous step) to src/main/resources
3. Write a Camel Route, either right in the Spring XML, or using the Java DSL (in another class under src/test/java somewhere). This route should use the Pipes and Filters integration pattern to:
   1. Start from the endpoint direct:start (which lets the test conveniently pass messages into the route)
   2. Call the endpoint xslt:YourXSLTFile.xsl to transform the message
   3. Send the result to the endpoint mock:finish (which lets the test verify the route output)
4. Add a test method to the unit test class that:
   1. Get a reference to the Mock endpoint mock:finish using code like this:

      Code Block
      java java
      MockEndpoint finish = MockEndpoint.resolve(camelContext, "mock:finish");

   2. Set the expectedMessageCount on that endpoint to 1
   3. Get a reference to the Customer 1 input file, using code like this:

      Code Block
      java java
      InputStream in = XMLInputTest.class.getResourceAsStream("/input-partner1.xml"); assertNotNull(in);

   4. Send that InputStream as a message to the direct:start endpoint, using code like this:

      Code Block
      java java
      template.sendBody("direct:start", in);

   5. Ensure that the message made it through the route to the final endpoint, by testing all configured Mock endpoints like this:

      Code Block
      java java
      MockEndpoint.assertIsSatisfied(camelContext);

   6. If you like, inspect the final message body using some code like finish.getExchanges().get(0).getIn().getBody().
      • If you do this, you'll need to know what format that body is – String, byte array, InputStream, etc.
5. Run your test with mvn install and make sure the build completes successfully.

Solution: Your finished test might look something like this:

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1. Create a new class under src/main/java, perhaps called CSVConverterBean.
2. Add a method, with one argument of type List<List<String>> and the return type Invoice
   • You may annotate the argument with @Body to specifically designate it as the body of the incoming message
3. In the method, the logic should look roughly like this:
   1. Create a new Invoice, using the method on the generated ObjectFactory class
   2. Loop through all the rows in the incoming CSV (the outer List)
   3. Skip the first row, which contains headers (column names)
   4. For the other rows:
      1. Create a new LineItemType (using the ObjectFactory again)
      2. Pick out all the cell values (the Strings in the inner List) and put them into the correct fields of the LineItemType
         • Not all of the values will actually go into the line item in this example
         • You may hardcode the column ordering based on the sample data file, or else try to read it dynamically from the headers in the first line
         • Note that you'll need to use a JAXB DatatypeFactory to create the XMLGregorianCalendar values that JAXB uses for the date fields in the XML – which probably means using a SimpleDateFormat to parse the date and setting that date on a GregorianCalendar
      3. Add the line item to the invoice
   5. Populate the partner ID, date of receipt, and order total on the Invoice
   6. Throw any exceptions out of the method, so Camel knows something went wrong
   7. Return the finished Invoice

Solution: Here's an example of what the CSVConverterBean might look like.

Create a unit test

Initial Work on Customer 3 Input (Excel over e-mail)

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