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https://issues.apache.org/jira/browse/CAMEL-20889?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17855930#comment-17855930
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Claus Ibsen commented on CAMEL-20889:
-------------------------------------
Yeah its a trade-off and affect everyone else and hence why the documentation
is also telling the user to reset the stream themselves if they get the body
again.
Also you should not do as in that sample code, you get the body once in a local
varaible and use that
String myBody = exchange.getBody(String.class);
And then use `myBody` if you need to access it again from the Processor
> camel-core: Stream is not reset when Message.getBody(class) is invoked ans
> stream caching is enabled
> ----------------------------------------------------------------------------------------------------
>
> Key: CAMEL-20889
> URL: https://issues.apache.org/jira/browse/CAMEL-20889
> Project: Camel
> Issue Type: Bug
> Components: came-core
> Reporter: Luigi De Masi
> Assignee: Luigi De Masi
> Priority: Major
>
> Having the following Camel route on Camel 2.x
> {code:java}
> from("timer:mytimer2?repeatCount=1&delay=1000")
> .routeId("generate-route-marshall")
> .streamCaching()
> .transform(constant("\{\"maskme\":\"json payload\"}"))
> .marshal().json(JsonLibrary.Jackson)
> .process(exchange ->
> {
> LOGGER.info("body class name -> " +
> exchange.getIn().getBody().getClass().getName());
> LOGGER.info("consumed once using .getBody(String.class) -> " +
> exchange.getIn().getBody(String.class));
> LOGGER.info("consumed twice using .getBody(String.class) -> " +
> exchange.getIn().getBody(String.class));
> })
> .to("jms:queue:INCOMING");
> {code}
>
> Shows that the consumption of the message payload in the processor via
> {code:java}
> exchange.getIn().getBody(String.class));\{code}
> works as expected, as the body is shown twice on the logs, as follows.
> {code:java}
> body class name -> org.apache.camel.converter.stream.InputStreamCache
> consumed once using .getBody(String.class) -> "\{\"maskme\":\"json
> payload\"}"
> consumed twice using .getBody(String.class) -> "\{\"maskme\":\"json
> payload\"}"
> {code}
>
> But if you run this same route from Camel 3.x to the latest 4.x one, you
> will get the following output:
> {code:java}
> body class name -> org.apache.camel.converter.stream.InputStreamCache
> consumed once using .getBody(String.class) -> "\{\"maskme\":\"json
> payload\"}"
> consumed once using .getBody(String.class) ->
> {code}
>
> The problem is that on Camel 2.x, when
> {{ exchange.getIn().getBody(String.class))}}
> is called, the
> [org.apache.camel.converter.IOConverterOptimised|https://github.com/apache/camel/blob/camel-2.x/camel-core/src/main/java/org/apache/camel/converter/IOConverterOptimised.java]
> is triggered to convert the body from
> {{org.apache.camel.converter.stream.InputStreamCache}} to
> {{{}java.lang.String{}}}, which at the beginning of the convertion, [it reset
> the
> stream|https://github.com/apache/camel/blob/a05826ece32fbb8e2ba6df0e0ac2a3d5903f9572/camel-core/src/main/java/org/apache/camel/converter/IOConverterOptimised.java#L50]:
>
> {code:java|title=IOConverterOptimised.java}
> public final class IOConverterOptimised {
> private IOConverterOptimised() {
> }
> public static Object convertTo(final Class<?> type, final Exchange
> exchange, final Object value) throws Exception {
> Class fromType = value.getClass();
> if (value instanceof StreamCache) {
> ((StreamCache)value).reset(); // <------ HERE
> }
> {code}
> From Camel 3.x,
> [org.apache.camel.converter.IOConverterOptimised|https://github.com/apache/camel/blob/camel-2.x/camel-core/src/main/java/org/apache/camel/converter/IOConverterOptimised.java]
> has been dropped, and
> [org.apache.camel.converter.IOConverter|https://github.com/apache/camel/blob/4c41ebcb73af761dcebf6e4ebb9a68e768e505a1/core/camel-base/src/main/java/org/apache/camel/converter/IOConverter.java]
> is used instead, which doesn't reset the stream.
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