Hi Recently I have spent some time to improve the type converters in Camel 2.10.
Most significant is the following changes a) fix important bug b) Fail fast c) tryConvertTo d) Expose utilization statistics Ad a) A bug was reported in https://issues.apache.org/jira/browse/CAMEL-5164 In summary if using camel-jaxb that offers a fallback type converter, and a failure occurs during XML marshalling, then subsequent new XML messages may fail, despite they were okay. Ad b) Due to a we need to detect this faster and better. So now the type converter system in Camel will fail fast by throwing a new TypeConversionException (its runtime). That allows Camel to detect the (a) failure faster from a fallback type converter (regular non fallback would fail fast already) This means the API is also consistent from caller point of view. You get a TypeConversionException if there was a failure during a type conversion attempt. Ad c) There is some places in camel-core where we want to only try to convert. For example with the binary predicates where you want to compare if X > Y. Then we try to coerce X and Y to numeric values. Likewise there is a few other spots where we do this, such as the XSLT component, where we try to use StAX, SAX, before DOM etc. So we have introduced a tryConvertTo API, which would not fail during type conversion. Ad d) The type converter system is used a lot in Camel during routing messages. Now we expose utilization statistics, which allow end users to spot if there is too many missing type conversion attempts. For example a route may attempt to convert, where there is no suitable type converter. This can now more easily be spotted, allowing the end user to either. Implement such a missing type converter, or correct a mistake in his application or the likes. The statistics is exposed in JMX and as well when Camel shutdown as a log line. On another note I am also hunting down to avoid using the PropertiesEditorTypeConverter, as it has many flaws - its not thread safe - its slow - and 3rd party projects can add property editors that influence Camel's type converts (eg ActiveMQ has a String -> List) properties editor that turns a String into a List of ActiveMQDestination instances. - it does not understand generics in List/Collection type, eg the ActiveMQ example above And basically we uses it only in Camel for doing some of the simpler basic conversions: String <-> Numeric. And so forth. But over the time we have added those as type converter directly in Camel, as they are faster as well. -- Claus Ibsen ----------------- CamelOne 2012 Conference, May 15-16, 2012: http://camelone.com FuseSource Email: cib...@fusesource.com Web: http://fusesource.com Twitter: davsclaus, fusenews Blog: http://davsclaus.blogspot.com/ Author of Camel in Action: http://www.manning.com/ibsen/
