我在Spring Integration 4.1.0中使用Spring 4.1.2。 我知道在Spring 4.1中添加了优化以允许编译SpEL表达式。
它说当前只有不支持：
话虽如此，有人可以看到为什么spring.expression.compiler.mode=MIXED无法编译以下内容吗？它是使用自定义解析器还是访问器？
expression="payload + '#{systemProperties['line.separator']}'"
我认为这可能是一项非常常见的任务。 它直接来自＆＃34;定义集成流程＆＃34;这个链接的一部分： https://spring.io/guides/gs/integration/
这里是完整的堆栈跟踪：
2014-12-04T16:47:55,035 [task-scheduler-1] [ERROR] (org.springframework.integration.handler.LoggingHandler) - org.springframework.integration.transformer.MessageTransformationException: ; nested exception is org.springframework.messaging.MessageHandlingException: Expression evaluation failed: payload + '
'; nested exception is java.lang.IllegalStateException: Failed to instantiate CompiledExpression
at org.springframework.integration.transformer.MessageTransformingHandler.handleRequestMessage(MessageTransformingHandler.java:74)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:99)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:101)
at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:97)
at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:277)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:239)
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:95)
at com.xxx.FileSplitter.sendOutput(FileSplitter.java:178)
at com.xxx.FileSplitter.produceOutputInternal(FileSplitter.java:146)
at com.xxx.FileSplitter.produceOutput(FileSplitter.java:69)
at org.springframework.integration.handler.AbstractMessageProducingHandler.sendOutputs(AbstractMessageProducingHandler.java:119)
at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:105)
at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:101)
at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:97)
at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:277)
at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:239)
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:95)
at org.springframework.integration.endpoint.SourcePollingChannelAdapter.handleMessage(SourcePollingChannelAdapter.java:110)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.doPoll(AbstractPollingEndpoint.java:219)
at org.springframework.integration.endpoint.AbstractPollingEndpoint.access$000(AbstractPollingEndpoint.java:55)
at org.springframework.integration.endpoint.AbstractPollingEndpoint$1.call(AbstractPollingEndpoint.java:149)
at org.springframework.integration.endpoint.AbstractPollingEndpoint$1.call(AbstractPollingEndpoint.java:146)
at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller$1.run(AbstractPollingEndpoint.java:298)
at org.springframework.integration.util.ErrorHandlingTaskExecutor$1.run(ErrorHandlingTaskExecutor.java:52)
at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50)
at org.springframework.integration.util.ErrorHandlingTaskExecutor.execute(ErrorHandlingTaskExecutor.java:49)
at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.run(AbstractPollingEndpoint.java:292)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:81)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.messaging.MessageHandlingException: Expression evaluation failed: payload + '
'; nested exception is java.lang.IllegalStateException: Failed to instantiate CompiledExpression
at org.springframework.integration.util.AbstractExpressionEvaluator.evaluateExpression(AbstractExpressionEvaluator.java:138)
at org.springframework.integration.handler.ExpressionEvaluatingMessageProcessor.processMessage(ExpressionEvaluatingMessageProcessor.java:72)
at org.springframework.integration.transformer.AbstractMessageProcessingTransformer.transform(AbstractMessageProcessingTransformer.java:64)
at org.springframework.integration.transformer.MessageTransformingHandler.handleRequestMessage(MessageTransformingHandler.java:68)
... 45 more
Caused by: java.lang.IllegalStateException: Failed to instantiate CompiledExpression
at org.springframework.expression.spel.standard.SpelCompiler.compile(SpelCompiler.java:111)
at org.springframework.expression.spel.standard.SpelExpression.compileExpression(SpelExpression.java:467)
at org.springframework.expression.spel.standard.SpelExpression.checkCompile(SpelExpression.java:443)
at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:331)
at org.springframework.integration.util.AbstractExpressionEvaluator.evaluateExpression(AbstractExpressionEvaluator.java:164)
at org.springframework.integration.util.AbstractExpressionEvaluator.evaluateExpression(AbstractExpressionEvaluator.java:123)
... 48 more
Caused by: java.lang.VerifyError: (class: spel/Ex2, method: getValue signature: (Ljava/lang/Object;Lorg/springframework/expression/EvaluationContext;)Ljava/lang/Object;) Incompatible argument to function
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2585)
at java.lang.Class.getConstructor0(Class.java:2885)
at java.lang.Class.newInstance(Class.java:350)
at org.springframework.expression.spel.standard.SpelCompiler.compile(SpelCompiler.java:108)
... 53 more
答案 0 :(得分：2)
表达式编译器不知道有效负载类型似乎存在问题。这有效......
expression="payload.toString() + '#{systemProperties['line.separator']}'"
...大概是因为我们告诉SpEL编译器LH参数的类型。
我会看到我能找到的东西。