camel-urlencode

This project shows the difference between defining an error handler on a RouteBuilder directly vs. using an explicit ErrorHandler.

Error handler defined on the route

The implementation can be found on branch main.

When the error handler is defined directly on the route:

Error handler defined directly on the route

@Override
public void configure() {
  // @formatter:off
  onException(Exception.class)
      .maximumRedeliveries(3)
      .log("Exception caught ${exchangeProperty.%s}".formatted(Exchange.EXCEPTION_CAUGHT))
      .onRedelivery(exchange -> log.info(
          "Redelivery {} / {}",
          exchange.getIn().getHeader(Exchange.REDELIVERY_COUNTER),
          exchange.getIn().getHeader(Exchange.REDELIVERY_MAX_COUNTER)));

  from(direct(DIRECT_ROUTE))
      .id(DIRECT_ROUTE)
      .log("Hello from direct route");
  // @formatter:on
}

the redelivery is executed first, and then the exception handler is executed:

log of a run with the error handler defined on a route directly

./mvnw clean test
...
[                          main] direct-route                   INFO  Hello from direct route
[                          main] MyDirectRoute                  INFO  Redelivery 1 / 3
[                          main] MyDirectRoute                  INFO  Redelivery 2 / 3
[                          main] MyDirectRoute                  INFO  Redelivery 3 / 3
[                          main] direct-route                   INFO  Exception caught java.lang.Exception: Test exception behaviour
...

Explicit error handler

The implementation can be found on branch error-handler.

When the error handler is defined explicitly:

Error handler defined explicitly

@Override
public void configure() {
  // @formatter:off
  errorHandler(new DefaultErrorHandlerBuilder()
      .maximumRedeliveries(3)
      .onExceptionOccurred(exchange -> log.info(
          "Exception caught {}",
          exchange.getProperty(Exchange.EXCEPTION_CAUGHT)))
      .onRedelivery(exchange -> log.info(
          "Redelivery {} / {}",
          exchange.getIn().getHeader(Exchange.REDELIVERY_COUNTER),
          exchange.getIn().getHeader(Exchange.REDELIVERY_MAX_COUNTER))));

  from(direct(DIRECT_ROUTE))
      .id(DIRECT_ROUTE)
      .log("Hello from direct route");
  // @formatter:on
}

the exception handler is executed first, and then the redelivery is executed:

log of a run with the error handler defined explicitly

./mvnw clean test
...
[                          main] direct-route                   INFO  Hello from direct route
[                          main] MyDirectRoute                  INFO  Exception caught java.lang.Exception: Test exception behaviour
[                          main] MyDirectRoute                  INFO  Redelivery 1 / 3
[                          main] MyDirectRoute                  INFO  Exception caught java.lang.Exception: Test exception behaviour
[                          main] MyDirectRoute                  INFO  Redelivery 2 / 3
[                          main] MyDirectRoute                  INFO  Exception caught java.lang.Exception: Test exception behaviour
[                          main] MyDirectRoute                  INFO  Redelivery 3 / 3
[                          main] MyDirectRoute                  INFO  Exception caught java.lang.Exception: Test exception behaviour
...

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Marco Bungart 💻 🚧 📖

This project follows the all-contributors specification. Contributions of any kind welcome!