camel route http response xml parsing - java

I am new to using camel and I need to build a route in JAVA to process some xml returned by http request. I tried to parse the body of the response by setting up a route with a processor and log it to a file setting the consumer as http url but it didn't work. Then I tried to set up a jms queue to grab and process it from the queue with similar result.
I think I am getting the 200 response but the producer text file I set it to write to is not working and the log4j in DEBUG is not too informative on isolating the issue. Does anyone have any insight on this issue to point me in the right camel direction? thanks in advance!
public static void main(String[] args) throws Exception {
CamelContext camelContext = new DefaultCamelContext();
// connect to embedded ActiveMQ JMS broker
ConnectionFactory connectionFactory =
new ActiveMQConnectionFactory("vm://localhost");
camelContext.addComponent("jms",
JmsComponent.jmsComponentAutoAcknowledge(connectionFactory));
try {
camelContext.addRoutes(new RouteBuilder() {
#Override
public void configure() throws Exception {
from("direct:start")
.to("http://tomcatappurl:8080/format=xml?bridgeEndpoint=true")
.process(new OrderProcessor())
.to("log:DEBUG?showBody=true&showHeaders=true")
.log("file:C:/Desktop/camellog1.txt")
.to("log:DEBUG?showBody=true&showHeaders=true")
.log("${headers}")
.convertBodyTo(String.class)
.to("file:C:/Desktop/camellog1.txt")
.log("${in.headers}")
.to("stream:out")
.to("jms");
from("jms:incomingOrders")
.process(new Processor() {
public void process (Exchange exchange) throws Exception {
//HttpServletRequest request = exchange.getIn().getBody(HttpServletRequest.class);
System.out.println("Response received from Google, is streamCaching = " + exchange.getContext().isStreamCaching());
System.out.println("----------------------------------------------IN MESSAGE--------------------------------------------------------------");
System.out.println(exchange.getIn().getBody(String.class));
System.out.println("----------------------------------------------OUT MESSAGE--------------------------------------------------------------");
//System.out.println(exchange.getOut().getBody(String.class)); //Activating this line causes empty response on browser
}
})
.to("file:C:/Users/Desktop/camellog1.txt?fileExist=Append");
}
});
camelContext.start();
} finally {
camelContext.stop();
}
}

I think your routes are not running.
You need something (like a timer) to trigger your routes, for example:
from("timer:myTimer?period=30s")
.to("direct:start");
Camel documentation for Direct component says:
The direct: component provides direct, synchronous invocation of any consumers when a producer sends a message exchange.
So you need something else to start the invocation of the route.
Mind that your first route must finish to the correct JMS queue:
// ... cut
.to("file:C:/Desktop/camellog1.txt")
.log("${in.headers}")
.to("stream:out")
.to("jms:incomingOrders");
without the queue name it will not work.

Related

Apache camel onException adding error details to the original message

I have added this exception handling to the camel route.
.onException(BeanCreationException.class, ValidationException.class)
.handled(true)
.process(new OnExceptionProcessor())
.to("errorQueue0").id("errorQueue")
.end()
public class OnExceptionProcessor implements Processor {
#Override
public void process(Exchange exchange) throws Exception {
Exception cause = exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
exchange.getIn().setHeader("FailedBecause", cause.getMessage());
}
}
When I read this message back from the error queue, I cannot find this header.
any idea on how to add error details along with the original message to the error queue
This could be a context problem because you are in a processor that is called by the error handler.
As an alternative, you could return the String value to set in the header from your processor method. By the way, this also improves the testability of your Processor.
Then you can use this return value to set the header in the error handler route directly.
.setHeader("FailedBecause", method(new OnExceptionProcessor()))

RabbitMQ Spring Java - RPC Pattern

I have some Spring applications that communicate between them using RabbitMQ as broker. I can send and receive messages asynchronously between them. But now, I need one application to send a message to another one and wait for the response. So, for this I am trying to implement the RPC pattern. It is working, but the problem is that I could only do it using temporary queues generated by Spring.
https://www.rabbitmq.com/tutorials/tutorial-six-spring-amqp.html
This is the code that sends the message and wait for the response.
public void send() {
....
Integer response = (Integer) template.convertSendAndReceive(exchange.getName(), "rpc", "message");
...
}
When I send the message, the execution is blocked until the response is received and a temporary queue is created by Spring for the response, as expected.
But what I need is to use a specific and fixed queue, defined by me, to receive the responses. I need responses to be sent to an exchange with a routing key pointing to the fixed response queue (doing this I'll be able to send the responses to another queue too, that will be logging all responses).
I tried setting the "setReplyTo" property to the message, but is not working.
What version are you using? With modern versions, direct reply_to is used by default, but you can revert to using a temporary queue by setting a property on the template.
https://docs.spring.io/spring-amqp/docs/current/reference/html/#direct-reply-to
To use a named reply queue, see the documentation about how to set up a reply container, with the template as the message listener:
https://docs.spring.io/spring-amqp/docs/current/reference/html/#message-correlation-with-a-reply-queue
and
https://docs.spring.io/spring-amqp/docs/current/reference/html/#reply-listener
EDIT
The template will block until the corresponding reply is passed into it by the reply container (or it times out).
#SpringBootApplication
public class So68986604Application {
public static void main(String[] args) {
SpringApplication.run(So68986604Application.class, args);
}
#RabbitListener(queues = "foo")
public String listen(String in) {
System.out.println(in);
return in.toUpperCase();
}
#Bean
Queue foo() {
return new Queue("foo");
}
#Bean
Queue replies() {
return new Queue("foo.replies");
}
#Bean
SimpleMessageListenerContainer replyContainer(ConnectionFactory cf, RabbitTemplate template) {
SimpleMessageListenerContainer replyer = new SimpleMessageListenerContainer(cf);
replyer.setQueueNames("foo.replies");
replyer.setMessageListener(template);
template.setReplyAddress("foo.replies");
return replyer;
}
#Bean
public ApplicationRunner runner(RabbitTemplate template) {
return args -> {
System.out.println(template.convertSendAndReceive("", "foo", "test"));
};
}
}
test
TEST

Post request response using Camel Netty4 - HTTP operation failed invoking

I'm new to Camel and am trying to get a response from a Netty4 route using a POST request. I'd like to send a JSON and return a string extracted from the body.
My rest setup is as follows:
public class Server extends RouteBuilder {
#Override
public void configure() {
String listenAddress = "0.0.0.0";
int listenPort = 8080;
restConfiguration()
.component("netty4-http")
.scheme("http")
.host(listenAddress)
.dataFormatProperty("prettyPrint", "true")
.bindingMode(RestBindingMode.auto)
.port(listenPort);
rest("/")
.post()
.consumes("application/json; charset=UTF-8")
.to("direct:post");
}
}
Within my Camel route I'd like to send the message back using:
#Component
public class RestRoute extends RouteBuilder {
#Autowired
CamelContext context;
#Override
public void configure() {
from("direct:post")
.log("New Request")
.streamCaching()
.setHeader(Exchange.HTTP_METHOD,constant(org.apache.camel.component.http4.HttpMethods.POST))
.setBody().jsonpath("$.Text") // extract text from JSON
.to("http4://0.0.0.0:8080?bridgeEndpoint=true");
However I get the following error: org.apache.camel.http.common.HttpOperationFailedException: HTTP operation failed invoking http://0.0.0.0:8080 with statusCode: 500
I'd appreciate some help!
Oh you should not send the message back, this happens automatic when the routing ends, then the message at that point is used as the response message for the rest.
So remove
.to("http4://0.0.0.0:8080?bridgeEndpoint=true");

Camel: how to route data from process method to another pipeline?

I have code like this:
.from("file://" + FTP_FILES + "?idempotent=true")
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
list = parseDataFromExchange(ecxhange);
}
I want to send this data to another pipeline vm:myEndpoint
I believe that Camel can this but google didn't help me.
How can I achieve this ?
Just use a ProducerTemplate from inside your Processor, then you can send any message to any Camel endpoint. You can find more information on the Camel website such as: http://camel.apache.org/producertemplate.html

Handle apache camel consumer errors

I want to stop route in case if user credentials changed, for this I want to handle javax.mail.AuthenticationFailedException.class but this does not work:
from(_getImapSentURL(emailConfiguration)).routeId(routeIdSent)
.onException(javax.mail.AuthenticationFailedException.class)
.process(new EmailErrorHandler()).end()
.process(new EmailContentSentProcessor(user, filterSent));
and error processor
public class EmailErrorHandler implements Processor {
private static final long serialVersionUID = 1L;
Logger logger = Logger.getLogger(getClass());
#Override
public void process(Exchange exchange) throws Exception {
logger.info("handled");
}
}
In console I'm getting this exception but it's not handled.
Where is the mistake?
Solution:
Add param to endpoint URL consumer.bridgeErrorHandler=true
In route builder add exception handler
onException(Exception.class)
.log("Exception occurred due: ${exception.message}")
.bean(new EmailConsumerExceptionHandler(), "handleException").handled(true)
.end();
Implement ExceptionHandler
Also if you set handle(..) to true you can access to exception only in this way
Exception cause = originalExchange.getProperty(
Exchange.EXCEPTION_CAUGHT, Exception.class);
in reffer to Apache camel documentation
Its like a chicken and egg situation. The Camel error handler reacts when you have a valid message to route and then during routing some error happens.
But as the mail consumer cannot login then there is no valid message to route.
But you can turn on an option to bridge the consumer with Camels error handler. You can find more details from here: http://camel.apache.org/why-does-my-file-consumer-not-pick-up-the-file-and-how-do-i-let-the-file-consumer-use-the-camel-error-handler.html and the links it refers to

Categories

Resources