I am trying to use the Apache Camel aws2 DyanamoDB component. In that there is a operation DescribeTable. I was trying that out.I have a camel rest API like so ->
.post("dynamodb-describe-table")
.route()
.process(new Processor(){
#Override
public void process(Exchange exchange) throws Exception {
exchange.getIn().setHeader("CamelAwsDdbTableName", "user");
}
})
.toD("aws2-ddb://user?accessKey=insert&secretKey=insert®ion=us-east-1&operation=DescribeTable")
.endRest();
This operation is run successfully but the response is null. Why is this happening?
Operation DescribeTable does not return body. All attributes are returned in form of Message headers.
All headers returned by this operation are listed in AWS DynamoDB documentation.
You have many options to create body, eg. with MVEL:
.transform().mvel("{" +
"'tableSize': exchange.in.headers.CamelAwsDdbTableSize," +
"'status': 'exchange.in.headers.CamelAwsDdbTableStatus'" +
"}")
Or Processor:
.process( exchange ->
exchange.getIn().setBody(
new HashMap<String, Object>(){{
put("tableSize", exchange.getMessage().getHeader("CamelAwsDdbTableSize"));
put("status", exchange.getMessage().getHeader("CamelAwsDdbTableStatus"));
// ...
}}
)
)
Between your toD() and endRest().
BTW I don't see any dynamic part in your URI, you should be able to use just to(), which i generally faster.
Related
I'm removing WSO2 from our stack and I have to write in Camel Java DSL the endpoints that were implemented in WSO2.
In WSO2 we had an endpoint as below:
<resource methods="OPTIONS GET" uri-template="/request/{data}" inSequence="requestreset"/>
<http method="GET" uri-template="http://127.0.0.1/index.php?_q=requestreset&data={uri.var.data}"/>
My code in Java Camel's Router is:
public class DefaultRouteBuilder extends RouteBuilder {
private HashMap<String, String> routeCorresponding = new HashMap();
#Override
public void configure() throws Exception {
routeCorresponding.put("reset/request/{data}", "http://127.0.0.1/index.php?_q=requestreset&data={data}");
for (Map.Entry<String, String> pair : routeCorresponding.entrySet()) {
String url = pair.getKey();
String target = pair.getValue();
String resultTarget = target.contains("?") ? target + "&bridgeEndpoint=true" : target + "?bridgeEndpoint=true";
fromF("servlet:"+ url +"?matchOnUriPrefix=true")
.log("Request: ${in.header."+ Exchange.HTTP_METHOD +"} to ${in.header."+ Exchange.HTTP_URI +"}")
.toF(resultTarget);
}
}
}
But it doesn't work as I would want it because when I make a request to tomcat.myserver.com:8080/camel-example-servlet/reset/request/blablablablabla I get a response this:
org.apache.camel.http.common.HttpOperationFailedException: HTTP operation failed invoking http://127.0.0.1/index.php/reset/request/blablablablabla?_q=requestreset&data=%7Bdata%7D with statusCode: 404
Instead of http://127.0.0.1/index.php/reset/request/blablablablabla?_q=requestreset&data=%7Bdata%7D, I would like the following request to be on http://127.0.0.1/index.php?_q=requestreset&data=blablablablabla
Is it possible to achieve in Camel/Java DSL that? Basically what WSO2 was implementing with the URI template and the curly brackets around fields?
You can absolutely achieve that - but your {data} block is stored as a header, so you need to refer to it as ${header.data} in your target URI.
Here's an example using the REST DSL:
restConfiguration().component("servlet");
rest("/reset/request/{data}")
.get()
.route()
.log("Received request...")
.setHeader(Exchange.HTTP_PATH, simple("/index.php"))
.setHeader(Exchange.HTTP_QUERY, simple("_q=requestreset&data=${header.data}"))
.to("http://localhost:8080?bridgeEndpoint=true");
Edit based on your question below. Alternatively, if you need to proxy hundreds of URLs, instead of creating hundreds of routes, you could just create one single route which proxies them all and implement your routing logic in a Processor, e.g.:
from("servlet:?matchOnUriPrefix=true")
.process(new Processor() {
public void process(Exchange exchange) throws Exception {
// set your target URI here, look it up from the HashMap, etc.
}
})
.to("http://localhost:8080?bridgeEndpoint=true");
I am new to Apache camel. I am trying to create routes to call multiple rest APIs and aggregate the response into one.
But for some reason, the JSON request that I am creating does not reach the rest endpoint.
During debug, I see that Exchange objects do have the values that I have set and get converted into byte array and on the other side, rest API recieves empty objects.
I am working on a Spring boot project and I have tried different ways of marshalling the request to JSON including Gson and Jackson. None of which seem to work.
Please assist.
from("direct:oneResponse")
.multicast(new MyAggregationStrategy()).parallelProcessing()
.to("direct:rest1call", "direct:rest2call")
.end();
from("direct:rest1call")
.routeId("rest1call")
.setHeader(Exchange.HTTP_METHOD, constant("POST"))
.setHeader("Content-Type", constant("application/json"))
.setHeader("Accept", constant("application/json"))
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
exchange.getIn().setBody(<<valid json>>); //json values as required for the rest call.
}
})
.to("http4://localhost:5555/mock/rest1call")
.setProperty("route", simple("routeId"))
.unmarshal(new JacksonDataFormat(Rest1Response.class));
from("direct:rest2call")
.routeId("rest2call")
.setHeader(Exchange.HTTP_METHOD, constant("POST"))
.setHeader("Content-Type", constant("application/json"))
.setHeader("Accept", constant("application/json"))
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
exchange.getIn().setBody(<<valid json>>); //json values as required for the rest call.
}
})
.to("http4://localhost:5555/mock/rest2call")
.setProperty("route", simple("routeId"))
.unmarshal(new JacksonDataFormat(Rest2Response.class));
Can you try to create a processor and specify all the headers and body in it?
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
exchange.getOut().setHeader(Exchange.HTTP_METHOD, HttpMethod.POST);
exchange.getOut().setHeader(Exchange.CONTENT_TYPE, "application/json");
exchange.getOut().setHeader("Accept", "application/json");
/* this is one way, string representation of json, but maybe you can try to build Model and fill that model with data */
exchange.getIn().setBody(<<valid json>>); //json values as required for the rest call.
}
})
if you decide to go with models, use marshaling after processor just to be sure your data is converted to JSON.
.marshal(yourDataFormat)
Try GsonDataFormat it works pretty good for me.
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
I'm passing a List of different objects to a camel route. I would like the route to split the body into one object per message and put the class of the body in a header (using a processor).
from("direct:in")
.split(body())
.process(new JmsTypeHeaderProcessor(body().getClass().getName()))
.to("mock:out");
I'm trying it like this...
#Produce(uri = "direct:in") private ProducerTemplate template;
#EndpointInject(uri = "mock:out") private MockEndpoint endpoint;
#Test
public void testRoute() throws Exception {
List<Object> list = new ArrayList<>();
list.add("String");
list.add(Integer.valueOf(1));
list.add(Boolean.FALSE);
template.sendBody(list);
for (Exchange ex : endpoint.getExchanges()) {
System.out.println("JMSType=" + ex.getIn().getHeader("JMSType"));
}
}
When I run that I find I actually have the headers
JMSType=org.apache.camel.builder.ValueBuilder
JMSType=org.apache.camel.builder.ValueBuilder
JMSType=org.apache.camel.builder.ValueBuilder
whereas I expected, and would like
JMSType=java.lang.String
JMSType=java.lang.Integer
JMSType=java.lang.Boolean
What is needed to get the class of the actual body?
BTW. I can see that log("body.class") returns what I want but I have not been able to follow how it works or adapt it for my needs.
The Camel routes are designed in the route builder and the code is run once, to setup the routes.
So this code
.process(new JmsTypeHeaderProcessor(body().getClass().getName()))
Is invoked once, and body().getClass() returns the ValueBuilder as that is what is used at design time in the DSL to specify body etc.
If you want to access the runtime message body, then get that from the Exchange from the process method of your processor. That is the runtime message and then you can get the body.
I have a Camel route with an onCompletion() which then hits a Processor. Within this processor it gets a header from the Exchange but this header comes back null.
I know that onCompletion() runs at the end of that particular route but surely the Exchange headers should still be valid and usable. inputLocation below is defined higher up in the class and works for previous routes.
from("file://"+inputLocation+"?initialDelay=5000&delay=2000&recursive=true&delete=true")
.onCompletion()
.process(storedProcProcessor())
.end()
.choice()
.when(appContext.getBean(AppPredicate.class))
.log("Need to check against APP in the database for destination.")
.setHeader(AppConstants.INPUTLOCATION, simple(inputLocation))
.process(databaseProcessor())
.endChoice();
I checked with:
#Override
public void configure() {
from("direct:start")
.onCompletion()
.process(new Processor() {
#Override
public void process(final Exchange exchange) throws Exception {
LOG.info("Hello, {}", exchange.getIn().getHeader("myHeader"));
}
})
.end()
.setHeader("myHeader").constant("World!");
}
}
This prints
Hello, World!
Thus, the header myHeader is still available in onCompletion. So, I guess that your header is never properly set?