Sorry Claus, Maybe I didn't represent the problem correctly.
I DO want to alter the body. In this case the result of processing the
body should be null.
Think of this example (not exactly my case but definitely something
that may be helpful).
I have a route that says:
from("jms:queue:processKey") #1
.bean("cacheValueExtractor") #2
.filter(body().isNull().log("not processing because value was not
in cache").stop().end() #3
.bean("beanWillProcessFromValueLookedUpFromCache")..... #4
In this case I'm sending a key (or maybe the name of a command) to be
processed. (#1)
The key maps some value in a cache (or is the key to a command that
should be executed) which should be processed. (#2)
If the value is not in the cache when looked up in
"cacheValueExtractor" you would return null as the object looked up.
Just so that beanWillProcessFromValueLookedUpFromCache will not have
to worry about invalid keys, we can add a filter (or choose) that the
value extracted was not null. (#3&4)
In this case it won't work though since JMSMessage will replace the
null returned from #2 and replace it with the original message (the
key in this case).
On Mon, Nov 22, 2010 at 7:42 AM, Claus Ibsen <claus.ib...@gmail.com> wrote:
> On Wed, Nov 17, 2010 at 9:59 PM, Tim <che...@gmail.com> wrote:
>> BTW, this is an error in logic in MessageSupport when interoperating
>> with JMSMessage it seems. I'm not quite sure what the intention was
>> when having it copy the old body over on null.
>>
>> Can a committer please either confirm this as a bug (and I can try to
>> patch that would fix this without breaking other intended
>> functionality) or explain to me why this is not a bug if it was
>> designed this way?
>>
>
> Its designed that way. If you dont want to alter the body using beans,
> then use a void method.
>
>
>> Thanks
>> -Tim
>>
>> On Tue, Nov 16, 2010 at 6:25 PM, Tim <che...@gmail.com> wrote:
>>> This is essentially a different incantation of CAMEL-2436
>>> (https://issues.apache.org/activemq/browse/CAMEL-2436)
>>> A test case that reproduces the issue is below.
>>> If you have a bean that returns null when processing the body of a
>>> JMSMessage you will not get the null in the next endpoint but rather
>>> the original message itself.
>>> One really hacky way around this bug is to replace the JMSMessage with
>>> a DefaultMessage by adding a processor
>>>
>>> .process(
>>> new Processor() {
>>> �...@override
>>> public void process(@NotNull Exchange
>>> anExchange) throws Exception {
>>> final DefaultMessage myIn = new
>>> DefaultMessage();
>>> myIn.setBody(anExchange.getIn().getBody());
>>> anExchange.setIn(myIn);
>>> }
>>> }
>>> )
>>>
>>> Into the below code after the from()
>>>
>>>
>>> import org.apache.activemq.ActiveMQConnectionFactory;
>>> import org.apache.activemq.command.ActiveMQObjectMessage;
>>> import org.apache.camel.Exchange;
>>> import org.apache.camel.Processor;
>>> import org.apache.camel.builder.RouteBuilder;
>>> import org.apache.camel.component.jms.JmsComponent;
>>> import org.apache.camel.component.jms.JmsMessage;
>>> import org.apache.camel.component.mock.MockEndpoint;
>>> import org.apache.camel.test.junit4.CamelTestSupport;
>>> import org.jetbrains.annotations.NotNull;
>>> import org.jetbrains.annotations.Nullable;
>>> import org.junit.Test;
>>>
>>> import javax.jms.JMSException;
>>>
>>> public class C2436Test extends CamelTestSupport {
>>> private static final String ENDPOINT1 = "jms:mock";
>>> private static final String ENDPOINT2 = "mock:results";
>>> private static final String TEST_CONTENT = "My Test Content";
>>>
>>> �...@notnull
>>> �...@override
>>> protected RouteBuilder createRouteBuilder() throws Exception {
>>> context.addComponent("jms", JmsComponent.jmsComponent(new
>>> ActiveMQConnectionFactory("vm://localhost")));
>>>
>>> return new RouteBuilder() {
>>> �...@override
>>> public void configure() throws Exception {
>>> from(ENDPOINT1)
>>> .bean(new ReturnsNull())
>>> .filter(body().isNull())
>>> .log("stopping:${body}")
>>> .stop()
>>> .end()
>>> .log("not-stopping:${body}")
>>> .to(ENDPOINT2);
>>> }
>>> };
>>> }
>>>
>>> �...@test
>>> public void testRoutePassing() throws InterruptedException, JMSException
>>> {
>>> final MockEndpoint myMockEndpoint = getMockEndpoint(ENDPOINT2);
>>>
>>> myMockEndpoint.expectedMessageCount(1);
>>> myMockEndpoint.allMessages().body().isNull();
>>>
>>> final ActiveMQObjectMessage myMessage = new ActiveMQObjectMessage();
>>> myMessage.setObject(TEST_CONTENT);
>>>
>>> template.send(ENDPOINT1, new Processor() {
>>> �...@override
>>> public void process(@NotNull Exchange anExchange) throws
>>> Exception {
>>> anExchange.setIn(new JmsMessage(myMessage, null));
>>> }
>>> });
>>>
>>> myMockEndpoint.assertIsSatisfied();
>>> }
>>>
>>> public class ReturnsNull {
>>> �...@nullable
>>> public String processMessage(@NotNull String aMessage) {
>>> return null;
>>> }
>>> }
>>> }
>>>
>>
>
>
>
> --
> Claus Ibsen
> -----------------
> FuseSource
> Email: cib...@fusesource.com
> Web: http://fusesource.com
> Twitter: davsclaus
> Blog: http://davsclaus.blogspot.com/
> Author of Camel in Action: http://www.manning.com/ibsen/
>
