Apache Camel: Unit testing for file and http components - junit

Question

I am fairly new to Camel & just managed to implement a use case as below with 2 routes which is using file & http components. Looking for some leads on writing junits for the same. Have tried some sample test case below based on the inputs that i found on the net. Not sure if that suffices. Appreciate your help!
Implementation:
#Override
public void configure() throws Exception {
// Global Exception Handling block
onException(FileWatcherException.class).process(new Processor() {
public void process(Exchange exchange) throws Exception {
System.out.println("Exception handled");
}
}).to("file:C:/error?recursive=true").handled(true);
// Actively listen to the input folder for an incoming file
from("file:C:/input?noop=true&recursive=true&delete=true")
.process(new Processor() {
public void process(Exchange exchange) throws Exception {
String fileName = exchange.getIn().getHeader("CamelFileName").toString();
exchange.getIn().setHeader("fileName", fileName);
}
})
// Call the Get endpoint with fileName as input parameter
.setHeader(Exchange.HTTP_METHOD, simple("GET"))
.toD("http://localhost:8090/fileWatcher?fileName=${header.fileName}")
.choice()
// if the API returns true, move the file to the outbox folder
.when(header(Exchange.HTTP_RESPONSE_CODE).isEqualTo(constant(200)))
.to("file:C:/outbox?noop=true&recursive=true")
.endChoice()
// If the API's response code is other than 200, move the file to error folder
.otherwise()
.log("Moving the file to error folder")
.to("file:C:/error?recursive=true")
.end();
// Listen to the outbox folder for file arrival after it gets moved in the above step
from("file:C:/outbox?noop=true&recursive=true")
// Request Body for POST call is set in FileDetailsProcessor class
.process(new FileDetailsProcessor())
.marshal(jsonDataFormat)
.setHeader(Exchange.HTTP_METHOD, simple("POST"))
.setHeader(Exchange.CONTENT_TYPE, constant("application/json"))
// Call the Rest endpoint with fileName & filePath as RequestBody
.to("http://localhost:8090/fileWatcher")
.process(new MyProcessor())
.end();
}
Junit
#Test
public void checkFileWatcherFunctionality() throws Exception {
context.getRouteDefinitions().get(0).adviceWith(context, new AdviceWithRouteBuilder() {
#Override
public void configure() throws Exception {
// mocking all endpoints. **QUESTION** - Is this required?
mockEndpointsAndSkip("http://localhost:8090:fileWatcher?fileName=loan.csv");
mockEndpointsAndSkip("file:C:/processing");
mockEndpointsAndSkip("file:C:/error");
mockEndpointsAndSkip("http://localhost:8090:fileWatcher");
}
});
context.start();
// **QUESTION** - This is a GET call. Expecting only the HTTP status code from it. How to check that?
getMockEndpoint("mock:http://localhost:8090:fileWatcher?fileName=abc.txt").expectedBodyReceived();
// **QUESTION** - This is a POST call. How to send request body along? Expecting only the HTTP status code from it. How to check that?
getMockEndpoint("mock:http://localhost:8090:fileWatcher").expectedBodyReceived();
// **QUESTION** - Is this the right way to check?
getMockEndpoint("mock:file:C:/processing").expectedFileExists("loan.csv");;
template.sendBodyAndHeader("file:C:/inbound", "", Exchange.FILE_NAME, "loan.csv");
// QUESTION - What can be asserted now?
}
Also - How to write test cases for negative flow (exception scenario)? Looking for suggestions.

Answer 1

I have managed to draft the test case. Is this the right approach or can there be a better way?
This might be more of an integration test i suppose.
The issue i see now is that the test case doesn't report at the end (success or failure), instead it keeps waiting for file arrival in the input folder. What am i missing?
#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class FileWatcherRouteBuilderTest extends CamelTestSupport {
#Autowired
private TestRestTemplate restTemplate;
#Override
public RoutesBuilder createRouteBuilder() throws Exception {
return new FileWatcherRouteBuilder();
}
#Test
public void testFileCopy() throws Exception {
template.sendBodyAndHeader("file:C:/inbound", "", Exchange.FILE_NAME, "abc.csv");
// Call the GET endpoint
ResponseEntity<String> getResponse = restTemplate.getForEntity("http:localhost:8090/fileWatcher?fileName=abc.csv",
String.class);
assertTrue("Get call is unsuccessful", getResponse.getStatusCode().is2xxSuccessful());
String response = getResponse.getBody();
assertTrue(!response.isEmpty());
// The file would have moved to output folder now.
File targetFile = new File("C:/processing");
assertTrue(targetFile.isDirectory());
assertEquals(1, targetFile.listFiles().length);
// Since we need to extract the file name, doing the below step
Exchange exchange = consumer.receive("file:C:/processing");
String fileName = exchange.getIn().getHeader("CamleFileName").toString();
// RequestBody needed for POST call
FileDetails fileDetails = new FileDetails(fileName, "C:/processing/"+fileName);
HttpHeaders headers = new HttpHeaders();
HttpEntity<FileDetails> request = new HttpEntity<FileDetails>(fileDetails, headers);
// Call the POST endpoint
ResponseEntity<String> postResponse = restTemplate.postForEntity("http://localhost:8090/fileWatcher", request, String.class);
assertTrue("Post call is unsuccessful", postResponse.getStatusCode().is2xxSuccessful());
// Asserting that after both the web service calls, the file is still available in the output folder
assertEquals(1, targetFile.listFiles().length);
}
}