How can I pass a session variable as parameter for maxRedeliveryAttempts field in rollback-exception-strategy component in Mule?

Question

Below is the Mule configuration XML.

<http:listener-config name="HTTP_Listener_Configuration" host="localhost" port="8090" doc:name="HTTP Listener Configuration"/>
<flow name="testflowFlow">
    <http:listener config-ref="HTTP_Listener_Configuration" path="/test" doc:name="HTTP"/>
    <set-session-variable variableName="count" value="#[message.inboundProperties.'http.query.params'.retrycount]" doc:name="count Session Variable"/>
    <set-payload value="#[sessionVars.count]" doc:name="Set Payload"/>
    <file:outbound-endpoint path="C:\Users\y0134079\Desktop" responseTimeout="10000" doc:name="File"/>
    <set-payload value="#[sessionVars.count]" doc:name="Set Payload"/>
    <rollback-exception-strategy maxRedeliveryAttempts="#[sessionVars.count]" doc:name="Rollback Exception Strategy"/>
</flow>

I trying to pass the maximum retries attempt in one of the query parameters (retrycount) in the HTTP request. But the maxredeliveryattempts field expect a integer and as the provided query parameter is a string the build has failed as it is not able o convert from string to integer. Any suggestions on this ?

Error :

*****Caused by: org.springframework.beans.TypeMismatchException: Failed to convert property value of type 'java.lang.String' to required type 'java.lang.Integer' for property 'maxRedeliveryAttempts'; nested exception is java.lang.NumberFormatException: For input string: "[sessionVars.count]" at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:468) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE]***** at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:494) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:488) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1464) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1423) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBea n(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:276) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-3.2. 10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBea n(AbstractBeanFactory.java:290) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:633) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.mule.config.spring.SpringRegistry.doInitialise(SpringRegistry.java:86) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.registry.AbstractRegistry.initialise(AbstractRegistry.java:105) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.spring.SpringXmlConfigurationBuilder.createSpringRegistry(SpringXmlConfigurationBuilder.java:135) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.config.spring.SpringXmlConfigurationBuilder.doConfigure(SpringXmlConfigurationBuilder.java:90) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AutoConfigurationBuilder.autoConfigure(AutoConfigurationBuilder.java:101) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AutoConfigurationBuilder.doConfigure(AutoConfigurationBuilder.java:52) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] at org.mule. config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory$1.configure(DefaultMuleContextFactory.java:84) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory.doCreateMuleContext(DefaultMuleContextFactory.java:217) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory.createMuleContext(DefaultMuleContextFactory.java:76) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:187) ~[mule-module-launcher-3.6.1.jar:3.6.1] ... 14 more Caused by: java.lang.NumberFormatException: For input string: "[sessionVars.count]" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65) ~[?:1.7.0_79] at java.lang.Integer.parseInt(Integer.java:492) ~[?:1.7.0_79] at java.lang.Integer.valueOf(Integer.java:556) ~[?:1.7.0_79] at java.lang.Integer.decod e(Integer.java:984) ~[?:1.7.0_79] at org.springframework.util.NumberUtils.parseNumber(NumberUtils.java:155) ~[spring-core-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.propertyeditors.CustomNumberEditor.setAsText(CustomNumberEditor.java:115) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.TypeConverterDelegate.doConvertTextValue(TypeConverterDelegate.java:455) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.TypeConverterDelegate.doConvertValue(TypeConverterDelegate.java:427) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:181) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:448) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:494) ~[spring -beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:488) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1464) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1423) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.Abstr actAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:276) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1418) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1159) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapable BeanFactory.java:519) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:191) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(Defa ultListableBeanFactory.java:633) ~[spring-beans-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479) ~[spring-context-3.2.10.RELEASE.jar:3.2.10.RELEASE] at org.mule.config.spring.SpringRegistry.doInitialise(SpringRegistry.java:86) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.registry.AbstractRegistry.initialise(AbstractRegistry.java:105) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.spring.SpringXmlConfigurationBuilder.createSpringRegistry(SpringXmlConfigurationBuilder.java:135) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.config.spring.SpringXmlConfigurationBuilder.doConfigure(SpringXmlConfigurationBuilder.java:90) ~[mule-module-spring-config-3.6.1.jar:3.6.1] at org.mule.config.builde rs.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AutoConfigurationBuilder.autoConfigure(AutoConfigurationBuilder.java:101) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AutoConfigurationBuilder.doConfigure(AutoConfigurationBuilder.java:52) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractConfigurationBuilder.configure(AbstractConfigurationBuilder.java:43) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.config.builders.AbstractResourceConfigurationBuilder.configure(AbstractResourceConfigurationBuilder.java:69) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory$1.configure(DefaultMuleContextFactory.java:84) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory.doCreateMuleContext(DefaultMul eContextFactory.java:217) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.context.DefaultMuleContextFactory.createMuleContext(DefaultMuleContextFactory.java:76) ~[mule-core-3.6.1.jar:3.6.1] at org.mule.module.launcher.application.DefaultMuleApplication.init(DefaultMuleApplication.java:187) ~[mule-module-launcher-3.6.1.jar:3.6.1] ... 14 more INFO 2016-05-03 08:13:33,029 [main] org.mule.module.launcher.DeploymentDirectoryWatcher: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + Mule is up and kicking (every 5000ms) + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ INFO 2016-05-03 08:13:33,239 [main] org.mule.module.launcher.StartupSummaryDeploymentListener:

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• • • • DOMAIN + - - * - - + STATUS + - - *

        ---

• default * DEPLOYED *

  ---

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• • • • APPLICATION + - - * - - + DOMAIN + - - * - - + STATUS + - - *

        ---

• testflow * default * FAILED *

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Answer 1

That attribute does not support MEL expressions. It supports spring property placeholders, but not dynamic MEL expressions. It is evaluated when initialized not runtime.

Answer 2

使用＃[Integer.parseInt（sessionVars.count）]