Details
Major Description
To easily reproduce issue. We have created this mini repo:
https://github.com/bugs84/springboot-camel-httpoutput-issue/tree/camel-minimal-sample
Description is in README.md
Issue description:
We are experiencing issue in our project after upgrading Apache Camel from version 3.10.0 to 3.11.0 (3.11.1 has the same issue). The same route which worked without any problems in previous versions, does not work now. We managed to simplify the route from our project and simulate the problem on this simplified route.
String synchronizerEndpoint = "direct:synchronizer"; String httpOutputEndpoint = "direct:httpOutput"; // HTTP Input from("servlet:///httpIssue?httpMethodRestrict=GET&servletName=CamelServlet") .log("Http request received") .process(new CorrelationIdGenerator()) .to(synchronizerEndpoint); // Parallel Synchronizer from(synchronizerEndpoint) .log("Parallel Synchronizer") .setHeader("scaler-sync-correlation", correlationExpression) .aggregate(correlationExpression, new MyRoutesAggregator()) .completionSize(1) .to(httpOutputEndpoint); // HTTP Output from(httpOutputEndpoint) .log("HTTP Output") .process(new ProcessHttpOutput());
n ProcessHttpOutput processor we are writing the response into the OutputStream:
private static class ProcessHttpOutput implements Processor { @Override public void process(Exchange exchange) throws Exception { HttpServletResponse response = exchange.getMessage().getBody(HttpMessage.class).getResponse(); response.setStatus(200); try (ServletOutputStream outputStream = response.getOutputStream()) { outputStream.write(("Response").getBytes(StandardCharsets.UTF_8)); outputStream.flush(); } } }
If we run this route on Camel version 3.11.0. We are getting NullPointerException during flushing / closing the stream. It works without any problems on 3.10.0.
The problem is if aggregation is in the route (without aggregation it works fine). After aggregation, it is not possible to write to the output stream.