Configure Spring Integration Aggregator via Java DSL under JDK 7

Question

This my first time to configure Spring Integration via DSL under Java 7. As we know the Lambda expression only works under Java 8. So I refer to the examples Spring Integration Java DSL and Spring Integration Java DSL (pre Java 8): Line by line tutorial to make my configuration as following to collect every 100 messages of same resource to send to remote RESTful service.

@Bean
public IntegrationFlow rawDataParsingAndSendingFlow(@Autowired HttpRequestExecutingMessageHandler httpOutboundAdapter,
                                          @Autowired @Qualifier("headerEnricher") HeaderEnricher headerEnricher) {

    return IntegrationFlows.from("rawStringParsingRequestChannel")
                           .transform(new RawStringToCheckDataMessageTransformer())
                           .transform(new DataMessageToDtoTransformer())
                           .aggregate(new Consumer<AggregatorSpec>(){

                                @Override public void accept(AggregatorSpec aggregatorSpec) {
                                    aggregatorSpec.processor(new SimpleMessageGroupProcessor(), null)
                                                  .correlationStrategy(new HeaderAttributeCorrelationStrategy("resource"))
                                                  .releaseStrategy(new MessageCountReleaseStrategy(100))
                                                  .sendPartialResultOnExpiry(true)
                                                  .groupTimeoutExpression("60000") ;
                                }
                           })
                           .transform(headerEnricher)
                           .transform(new ObjectToJsonTransformer())
                           .handle(httpOutboundAdapter)
                           .get();
}

However, configuration doesn't work for me and it throws exception as following.

Exception in thread "main" java.lang.IllegalStateException: Failed to process message list
    at org.springframework.integration.aggregator.MethodInvokingMessageListProcessor.process(MethodInvokingMessageListProcessor.java:79)
    at org.springframework.integration.aggregator.MethodInvokingMessageGroupProcessor.aggregatePayloads(MethodInvokingMessageGroupProcessor.java:86)
    at org.springframework.integration.aggregator.AbstractAggregatingMessageGroupProcessor.processMessageGroup(AbstractAggregatingMessageGroupProcessor.java:84)
    at org.springframework.integration.dsl.AggregatorSpec$MessageGroupProcessorWrapper.processMessageGroup(AggregatorSpec.java:127)
    at org.springframework.integration.aggregator.AbstractCorrelatingMessageHandler.completeGroup(AbstractCorrelatingMessageHandler.java:665)
    at org.springframework.integration.aggregator.AbstractCorrelatingMessageHandler.handleMessageInternal(AbstractCorrelatingMessageHandler.java:418)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:127)
    at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:148)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:358)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:269)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:186)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:115)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:127)
    at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:148)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutput(AbstractMessageProducingHandler.java:358)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.produceOutput(AbstractMessageProducingHandler.java:269)
    at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:186)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:115)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:127)
    at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:148)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121)
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423)
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:115)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:45)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:105)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:143)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.convertAndSend(AbstractMessageSendingTemplate.java:135)
    at org.springframework.integration.gateway.MessagingGatewaySupport.send(MessagingGatewaySupport.java:392)
    at org.springframework.integration.gateway.GatewayProxyFactoryBean.invokeGatewayMethod(GatewayProxyFactoryBean.java:477)
    at org.springframework.integration.gateway.GatewayProxyFactoryBean.doInvoke(GatewayProxyFactoryBean.java:429)
    at org.springframework.integration.gateway.GatewayProxyFactoryBean.invoke(GatewayProxyFactoryBean.java:420)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy45.sendRawData(Unknown Source)
    at prototype.healthcloud.historic.data.pusher.HistoricDataRetriever$1.extractData(HistoricDataRetriever.java:82)
    at prototype.healthcloud.historic.data.pusher.HistoricDataRetriever$1.extractData(HistoricDataRetriever.java:68)
    at org.springframework.jdbc.core.JdbcTemplate$1.doInPreparedStatement(JdbcTemplate.java:697)
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:633)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:684)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:716)
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:726)
    at prototype.healthcloud.historic.data.pusher.HistoricDataRetriever.retrieveHistoricData(HistoricDataRetriever.java:92)
    at prototype.healthcloud.historic.data.pusher.Application.main(Application.java:119)
Caused by: org.springframework.expression.AccessException: Unable to access property 'payload' through getter method
    at org.springframework.expression.spel.support.ReflectivePropertyAccessor$OptimalPropertyAccessor.read(ReflectivePropertyAccessor.java:640)
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:211)
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:94)
    at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:81)
    at org.springframework.expression.spel.ast.MethodReference.getArguments(MethodReference.java:154)
    at org.springframework.expression.spel.ast.MethodReference.getValueRef(MethodReference.java:71)
    at org.springframework.expression.spel.ast.CompoundExpression.getValueRef(CompoundExpression.java:66)
    at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:87)
    at org.springframework.expression.spel.ast.SpelNodeImpl.getTypedValue(SpelNodeImpl.java:131)
    at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:330)
    at org.springframework.integration.util.AbstractExpressionEvaluator.evaluateExpression(AbstractExpressionEvaluator.java:169)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.processInternal(MessagingMethodInvokerHelper.java:319)
    at org.springframework.integration.util.MessagingMethodInvokerHelper.process(MessagingMethodInvokerHelper.java:160)
    at org.springframework.integration.aggregator.MethodInvokingMessageListProcessor.process(MethodInvokingMessageListProcessor.java:73)
    ... 61 more
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.expression.spel.support.ReflectivePropertyAccessor$OptimalPropertyAccessor.read(ReflectivePropertyAccessor.java:636)
    ... 74 more
Caused by: java.lang.IllegalStateException: Invalid method parameter for payload: was expecting collection.
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.integration.util.MessagingMethodInvokerHelper$ParametersWrapper.getPayload(MessagingMethodInvokerHelper.java:920)
    ... 79 more

The root cause is in o.s.i.u.MessagingMethodInvokerHelper$HandlerMethod method generateExpression, the annotationType is NULL and the parameterType o.s.i.s.MessageGroup is neither sub-interface of Collection, Collection<Message<?>> or array, so the expression will be set to '#target.processMessageGroup(payload)'. I guess additional logic block have to be added to process MessageGroup type properly (not sure).

Since my aggregation logic is quite simple, I found a work around solution by specifying outputExpression as following.

@Bean
public IntegrationFlow rawDataParsingAndSendingFlow(@Autowired HttpRequestExecutingMessageHandler httpOutboundAdapter,
                                          @Autowired @Qualifier("headerEnricher") HeaderEnricher headerEnricher) {

    return IntegrationFlows.from("rawStringParsingRequestChannel")
                           .transform(new RawStringToCheckDataMessageTransformer())
                           .transform(new DataMessageToDtoTransformer())
                           .aggregate(new Consumer<AggregatorSpec>(){

                                @Override public void accept(AggregatorSpec aggregatorSpec) {
                                    aggregatorSpec.outputExpression("#this.![payload]")
                                                  .correlationStrategy(new HeaderAttributeCorrelationStrategy("resource"))
                                                  .releaseStrategy(new MessageCountReleaseStrategy(100))
                                                  .sendPartialResultOnExpiry(true)
                                                  .groupTimeoutExpression("60000") ;
                                }
                           })
                           .transform(headerEnricher)
                           .transform(new ObjectToJsonTransformer())
                           .handle(httpOutboundAdapter)
                           .get();
}

So far the work-around solution works for me, but my question is how to configure processor if the aggregation logic is complex.

The version of Spring Integration is 4.3.10.RELEASE – Flik Shen Jul 17 '17 at 08:00 — Flik Shen, Jul 17 '17 at 08:00

score 0 · Accepted Answer · answered Jul 17 '17 at 12:42

0

aggregatorSpec.processor(new SimpleMessageGroupProcessor(), null)

You can't use a concrete MessageGroupProcessor with that method; it is expecting a POJO bean and method name (which can be null if there's only one eligible method on the bean).

use

aggregatorSpec.outputProcessor(new SimpleMessageGroupProcessor())

Note that the output from that processor will be the message group, which is probably not what you want.

You might want to consider using DefaultAggregatingMessageGroupProcessor (which is the default if you don't provide an outputProcessor).

answered Jul 17 '17 at 12:42

Gary Russell

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Neither SimpleMessageGroupProcessor nor DefaultAggregatingMessageGroupProcessor without method name works for me and same exception is raised. – Flik Shen Jul 18 '17 at 02:51
You are right and the POJO aggregator works correct although it looks a bit odd like `public class PayloadExtractingAggregator {@Aggregator public List extract(List dtos) {return dots;}}` and DSL is `aggregatorSpec.processor(payloadExtractingAggregator(), "extract")` – Flik Shen Jul 18 '17 at 03:42
Don't put code in comments; it's not very readable; edit the question (or answer) instead. Perhaps you mis-read my answer? When using a concrete `MessageGroupProcessor` the method is `.outputProcessor(...)` instead of `.processor(...)`. – Gary Russell Jul 18 '17 at 12:49
Sorry for missing your point. Now it's clear to me. Thanks a lot. – Flik Shen Jul 19 '17 at 05:48

Configure Spring Integration Aggregator via Java DSL under JDK 7

1 Answers1