Unmarshal InputStream using BeanIO and Apache Camel

Question

I have a service that receives a file and send it to a Camel route. On that route, I’d like to unmarshal that file using BeanIO, but it doesn’t recognize inputs of type InputStream.

@RestController
@RequestMapping(value = "/file")
public class FileController {

    @Autowired
    private CamelContext camelContext;

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    public void upload(@RequestParam("file") MultipartFile multipartFile) throws IOException {
        ProducerTemplate template = camelContext.createProducerTemplate();
        template.sendBody("direct:routeTest", new ByteArrayInputStream(multipartFile.getBytes()));
    }

}

@Component
public class SampleRouter extends RouteBuilder {

    @Override
    public void configure() throws Exception {
        from("direct:routeTest")
                .log("${body}")
                .to("dataformat:beanio:unmarshal?mapping=mapping.xml&streamName=testFile")
                .process(msg -> msg.getIn()
                        .getBody(List.class)
                        .forEach(o -> {...}))
                .end();
    }

}

I have tested a route that reads the file using the File component, and sends the result to the BeanIO component. In that case it works.

How can I use BeanIO with inputs of type InputStream on Apache Camel? Is there any component that can transform my InputStream into something compatible with the BeanIO component?

Did you get any exception? Did you get any output message on `log("${body}")`? — mgyongyosi, Aug 22 '17 at 10:41
No exceptions. `.log("${body}")` gives me the content of the file. It turns out that the problem was exactly that line. I thought that `.log("${body}")` would return the body's content to the next route, but it doesn't return anything. When I removed this line, it worked. — Marcos Tanaka, Aug 22 '17 at 11:58
Yep, when you called `.log("${body}")` on the InputStream it read the stream and after that the position was at the end of the stream. — mgyongyosi, Aug 22 '17 at 12:07

Marcos Tanaka · Answer 1 · 2017-08-22T12:27:55.583

As mgyongyosi said, when .log("${body}") reads the stream, the position go to the end of it. To solve this we can reset the position of the InputStream after reading it:

from("direct:routeTest")
        .log("${body}")
        .process(exchange -> ((InputStream) exchange.getIn().getBody()).reset())
        .to("dataformat:beanio:unmarshal?mapping=mapping.xml&streamName=testFile")

or remove the line .log("${body}").

mgyongyosi · Accepted Answer · 2017-08-22T21:58:04.377

1

Other solution can be to add .streamCaching() to the route. Then you can read the same stream multiple times. Official documentation

edited Aug 22 '17 at 21:58

answered Aug 22 '17 at 21:52

mgyongyosi

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Unmarshal InputStream using BeanIO and Apache Camel

2 Answers2