Apache Camel: How to retain original attachments after split? - apache-camel

I'm using the Split EIP, trying to either access all attachments from the original in message or to copy all attachments from the original in message to the in message of the sub-exchange.
I've found that this works, but it looks strange to me:
…
// Save attachments in some header:
.setHeader("savedAttachments", new Expression() {
#Override
public <T> T evaluate(final Exchange exchange, final Class<T> aClass) {
return (T) exchange.getIn().getAttachments();
}
})
.split(…)
// Restore attachments:
.process(exchange -> exchange.getIn().setAttachments((Map<String, DataHandler>) it.getIn().getHeader("savedAttachments")))
…
Is this how to do it? Or is there a better way?
I've also tried several combinations of context.setAllowUseOriginalMessage(true); and .split(…).shareUnitOfWork() and exchange.getUnitOfWork().getOriginalInMessage().getAttachments() but I couldn't access the original attachments that way.
Thanks
John

Related

Camel doesn't retrieve SQS messages attributes

Here is the route:
from("aws-sqs://myQueue?accessKey=RAW(xxx)&secretKey=RAW(yyy)&deleteAfterRead=false")
.log("Attributes: ${header.CamelAwsSqsAttributes}")
.process(new Processor() {
#Override
public void process(Exchange exchange) throws Exception {
Map<String, String> messageAttributes = (Map<String, String>) exchange.getIn().getHeader("CamelAwsSqsAttributes");
...
}
});
The .log() shows an empty map as well as if I print messageAttributes from the processor.
I also tried with the header "CamelAwsSqsMessageAttributes" instead of "CamelAwsSqsAttributes" but still nothing.
I see the attributes from the AWS console though.
By the way I get the message body, and I use Camel 2.15
I figured it out, here is an example to get queue attributes and message attributes:
main.bind("sqsAttributeNames", Collections.singletonList("All"));
main.bind("sqsMessageAttributeNames", Collections.singletonList("All"));
Or add those objects to the registry if you don't use org.apache.camel.main.Main
Then:
from("aws-sqs://myQueue?accessKey=RAW(xxx)&secretKey=RAW(yyy)&deleteAfterRead=false&attributeNames=#sqsAttributeNames&messageAttributeNames=#sqsMessageAttributeNames")
Of course you can replace Collections.singletonList("All") with the list of attributes you need if you don't want all of them.
I faced the same issue. When I am using camel-aws 2.16.x and I have my endpoint configured as follow
from("aws-sqs://myQueue?...&messageAttributeNames=#sqsMsgAttributeNames")
.to(...)
Then I have defined a Collection of String in my spring configuration file
#Bean
public Collection<String> sqsMsgAttributeNames() {
return Arrays.asList("Attr1", "Attr2");
}
Above settings work fine but ever since I upgraded to camel-aws 2.17.3. It no longer works. As mentioned in Camel SQS Component, collection of string no longer will be supported for messageAttributeNames and it should be a String with attributes separated by comma.
Note: The string containing attributes should not contain any white
spaces otherwise camel-aws component will only read the first
attribute. I went through the pain to debug on this. Besides, setting the
attribute value to be "All" does not work for me, none of the message
attributes will be read.
Below is the changes I made that allowed camel-aws's SqsConsumer to work again:
#Bean
public String sqsMsgAttributeNames() {
return String.format("%s,%s", "Attr1", "Attr2");
}
It is not an issue of Camel. It can be the default behavior of SQS or aws-java-sdk-core library.
As a quick solution this aws-sqs URL can be used
aws-sqs://myQueue?<other attributes here>&attributeNames=All
Keep in mind that localstack can work well without attributeNames parameter, unlike SQS.

Using apache camel csv processor with pollEnrich pattern?

Apache Camel 2.12.1
Is it possible to use the Camel CSV component with a pollEnrich? Every example I see is like:
from("file:somefile.csv").marshal...
Whereas I'm using the pollEnrich, like:
pollEnrich("file:somefile.csv", new CSVAggregator())
So within CSVAggregator I have no csv...I just have a file, which I have to do csv processing myself. So is there a way of hooking up the marshalling to the enrich bit somehow...?
EDIT
To make this more general... eg:
from("direct:start")
.to("http:www.blah")
.enrich("file:someFile.csv", new CSVAggregationStrategy) <--how can I call marshal() on this?
...
public class CSVAggregator implements AggregationStrategy {
#Override
public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
/* Here I have:
oldExchange = results of http blah endpoint
newExchange = the someFile.csv GenericFile object */
}
Is there any way I can avoid this and use marshal().csv sort of call on the route itself?
Thanks,
Mr Tea
You can use any endpoint in enrich. That includes direct endpoints pointing to other routes. Your example...
Replace this:
from("direct:start")
.to("http:www.blah")
.enrich("file:someFile.csv", new CSVAggregationStrategy)
With this:
from("direct:start")
.to("http:www.blah")
.enrich("direct:readSomeFile", new CSVAggregationStrategy);
from("direct:readSomeFile")
.to("file:someFile.csv")
.unmarshal(myDataFormat);
I ran into the same issue and managed to solve it with the following code (note, I'm using the scala dsl). My use case was slightly different, I wanted to load a CSV file and enrich it with data from an additional static CSV file.
from("direct:start") pollEnrich("file:c:/data/inbox?fileName=vipleaderboard.inclusions.csv&noop=true") unmarshal(csv)
from("file:c:/data/inbox?fileName=vipleaderboard.${date:now:yyyyMMdd}.csv") unmarshal(csv) enrich("direct:start", (current:Exchange, myStatic:Exchange) => {
// both exchange in bodies will contain lists instead of the file handles
})
Here the second route is the one which looks for a file in a specific directory. It unmarshals the CSV data from any matching file it finds and enriches it with the direct route defined in the preceding line. That route is pollEnriching with my static file and as I don't define an aggregation strategy it just replaces the contents of the body with the static file data. I can then unmarshal that from CSV and return the data.
The aggregation function in the second route then has access to both files' CSV data as List<List<String>> instead of just a file.

Put modified xml back into the message?

I'm using CXF to send messages with SOAP over JMS.
I'm trying to write a CXF Interceptor in the POST_MARSHALL phase.
I want to change some attributes when the xml is generated.
I know i can get the content from the message via
message.getContent(java.io.Writer.class).
This happens to be in the form of JMSConduit$1. Which - I think - is a StringWriter (if I debug my code I can see a buf field).
I can get the xml in String format and make my changes, but the problems is putting it back in the message.
I can not change the JMSConduit$1 to something else, otherwise CXF won't send it to the JMS Endpoint. (it must be a JMSConduit).
I can't find a way to put the modified xml back in a JMSConduit, which i can get through
message.getExchange().getConduit();
So, how can I put my modified xml back into the message/JMSConduit?
Finally found an answer. I used a FilterWriter.
public void handleMessage(Message message) throws Fault {
final Writer writer = message.getContent(Writer.class);
message.setContent(Writer.class, new OutWriter(message, writer));
}
class OutWriter extends FilterWriter {
#Override
public void close() throws IOException {
// Modify String (in xml form).
message.setContent(Writer.class, out);
}
}

Apache Camel: can message have multiple objects in body (with different classes)?

I have almost ready application in java that use jms with Camel. Pop up that we I have to add additional infomations in exchange/message. Lets say that those additional infomations are in fact new java object. What is the best way to add my new object to exchange?
I have a lot of Camel processors processing the message that look like this:
public class MyProcessor implements Processor {
#Override
public void process(Exchange exchange) throws Exception {
String s = exchange.getIn().getBody(String.class);
s = magicalTransform(s);
exchange.getIn().setBody(s, String.class);
//Now I have to add object of some Info.cass:
Info info = new Info( new Date() );
//Can I add it like this? :
exchange.getIn().setBody(info, Info.class);
}
}
The problem is that I can't find information if I can add many objects to Message. The Message method: setBody(Object body, Class type) suggest that it is possible, but there is also method: getBody() that sugesst that there is only one body class.
If I can't do it in this way, then what's the best way? I could try to wrap String that I transform and info in to one class, and put that new class in to message, but It will cause change the way obtaining String in every Processor. I want to avoid that.
The body of an Exchange is a single Object. If you want to add multiple objects to the body of your exchange you need to make the body of the exchange a map, list, or pojo with fields that you set all of your objects within.

Handling multipart attachments in CXF APIs

I am trying to develop an API call using Apache CXF that takes in an attachment along with the request. I followed this tutorial and this is what I have got so far.
#POST
#Path("/upload")
#RequireAuthentication(false)
public Response uploadWadl(MultipartBody multipartBody){
List<Attachment> attachments = multipartBody.getAllAttachments();
DataHandler dataHandler = attachments.get(0).getDataHandler();
try {
InputStream is = dataHandler.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
return Response("OK");
}
I am getting an InputStream object to the attachment and everything is working fine. However I need to pass the attachment as a java.io.File object to another function. I know I can create a file here, read from the inputstream and write to it. But is there a better solution? Has the CXF already stored it as a File? If so I could just go ahead and use that. Any suggestions?
I'm also interested on this matter. While discussing with Sergey on the CXF mailing list, I learned that CXF is using a temporary file if the attachment is over a certain threshold.
In the process I discovered this blogpost that explains how to use CXF attachment safely.
You can be interested by the exemple on this page as well.
That's all I can say at the moment as I'm investigating right now, I hope that helps.
EDIT : At the moment here's how we handle attachment with CXF 2.6.x. About uploading a file using multipart content type.
In our REST resource we have defined the following method :
#POST
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.MULTIPART_FORM_DATA)
#Path("/")
public Response archive(
#Multipart(value = "title", required = false) String title,
#Multipart(value = "hash", required = false) #Hash(optional = true) String hash,
#Multipart(value = "file") #NotNull Attachment attachment) {
...
IncomingFile incomingFile = attachment.getObject(IncomingFile.class);
...
}
A few notes on that snippet :
#Multipart is not standard to JAXRS, it's not even in JAXRS 2, it's part of CXF.
In our code we have implemented bean validation (you have to do it yourself in JAXRS 1)
You don't have to use a MultipartBody, the key here is to use an argument of type Attachment
So yes as far as we know there is not yet a possibility to get directly the type we want in the method signature. So for example if you just want the InputStream of the attachment you cannot put it in the signature of the method. You have to use the org.apache.cxf.jaxrs.ext.multipart.Attachment type and write the following statement :
InputStream inputStream = attachment.getObject(InputStream.class);
Also we discovered with the help of Sergey Beryozkin that we could transform or wrap this InputStream, that's why in the above snippet we wrote :
IncomingFile incomingFile = attachment.getObject(IncomingFile.class);
IncomingFile is our custom wrapper around the InputStream, for that you have to register a MessageBodyReader, ParamHandler won't help as they don't work with streams but with String.
#Component
#Provider
#Consumes
public class IncomingFileAttachmentProvider implements MessageBodyReader<IncomingFile> {
#Override
public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return type != null && type.isAssignableFrom(IncomingFile.class);
}
#Override
public IncomingFile readFrom(Class<IncomingFile> type,
Type genericType,
Annotation[] annotations,
MediaType mediaType,
MultivaluedMap<String, String> httpHeaders,
InputStream entityStream
) throws IOException, WebApplicationException {
return createIncomingFile(entityStream, fixedContentHeaders(httpHeaders)); // the code that will return an IncomingFile
}
}
Note however that there have been a few trials to understand what was passed, how, and the way to hot-fix bugs (For example the first letter of the first header of the attachment part was eat so you had ontent-Type instead of Content-Type).
Of course the entityStream represents the actual InputStream of the attachment. This stream will read data either from memory or from disk, depending on where CXF put the data ; there is a size threshold property (attachment-memory-threshold) for that matter. You can also say where the temporary attachments will go (attachment-directory).
Just don't forget to close the stream when you are done (some tool do it for you).
Once everything was configured we tested it with Rest-Assured from Johan Haleby. (Some code are part of our test utils though) :
given().log().all()
.multiPart("title", "the.title")
.multiPart("file", file.getName(), file.getBytes(), file.getMimeType())
.expect().log().all()
.statusCode(200)
.body("store_event_id", equalTo("1111111111"))
.when()
.post(host().base().endWith("/store").toStringUrl());
Or if you need to upload the file via curl in such a way :
curl --trace -v -k -f
--header "Authorization: Bearer b46704ff-fd1d-4225-9dd4-e29065532b73"
--header "Content-Type: multipart/form-data"
--form "hash={SHA256}3e954efb149aeaa99e321ffe6fd581f84d5a497b6fab5c86e0d5ab20201f7eb5"
--form "title=fantastic-video.mp4"
--form "archive=#/the/path/to/the/file/fantastic-video.mp4;type=video/mp4"
-X POST http://localhost:8080/api/video/event/store
To finish this answer, I'd like to mention it is possible to have JSON payload in multipart, for that you can use an Attachment type in the signature and then write
Book book = attachment.getObject(Book.class)
Or you can write an argument like :
#Multipart(value="book", type="application/json") Book book
Just don't forget to add the Content-Type header to the relevant part when performing the request.
It might be worth to say that it is possible to have all the parts in a list, just write a method with a single argument of type List<Attachment>. However I prefer to have the actual arguments in the method signature as it's cleaner and less boilerplate.
#POST
void takeAllParts(List<Attachment> attachments)

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