Transfer a file using Apache Camel file component - spring

Question

I am trying a demo file transfer program using Spring Boot and Apache Camel file component. I have exposed a REST Controller using Spring Boot which is calling an Apache Camel route and it is doing the file transfer. I have three files in the directory C:\CamelDemo\inputFolder namely input1.txt, input2.txt and input3.txt. I want to only transfer the file input2.txt in the output folder. My Spring Boot controller is as below:
package com.example.demo.controller;
import java.util.HashMap;
import java.util.Map;
import org.apache.camel.ProducerTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
#RestController
#RequestMapping("/camel")
public class FileTransferController {
#Autowired private ProducerTemplate producerTemplate;
#RequestMapping(value="/file", method=RequestMethod.GET)
public String callCamelRoute() {
String fileName = "input2.txt";
Map<String, Object> headerMap = new HashMap<String, Object>();
headerMap.put("fileName", fileName);
producerTemplate.sendBodyAndHeaders("direct:transferFile", null, headerMap);
return "Route invoked";
}
}
My Route is as below:
package com.example.demo.route;
import org.apache.camel.LoggingLevel;
import org.apache.camel.builder.RouteBuilder;
import org.springframework.stereotype.Component;
#Component
public class FileTransferRoute extends RouteBuilder {
#SuppressWarnings("deprecation")
#Override
public void configure() {
errorHandler(defaultErrorHandler()
.maximumRedeliveries(3)
.redeliverDelay(1000)
.retryAttemptedLogLevel(LoggingLevel.WARN));
from("direct:transferFile")
.log("Route reached")
.log("file:C:\\CamelDemo\\inputFolder?fileName=${in.headers.fileName}&noop=true")
.pollEnrich("file://C:/CamelDemo/inputFolder?fileName=${in.headers.fileName}&noop=true")
.to("file://C:/CamelDemo/outputFolder?autoCreate=false")
.end();
}
}
But the first time I invoke this route, the file input1.txt is getting transferred even when I have specified the fileName parameter. Please help.

Answer 1

I think the issue is that your file name isn't being set, because you're not telling Camel that you're using a Simple expression, rather than a fixed URI.
Looking at the manual (https://camel.apache.org/manual/latest/pollEnrich-eip.html#_using_dynamic_uris), it implies that you will need
.pollEnrich().simple("file://C:/CamelDemo/inputFolder?fileName=${in.headers.fileName}&noop=true")
to be able to use the dynamic endpoint.