將spring-flex從1.0.3升級到1.5.2會導致NullPointerException

Question

我一直在試圖將spring-flex 1.0.3升級到1.5.2，以便檢查新功能，即在BlazeDS 4中支持Hibernate惰性讀取支持。下載了所有必要的軟件包，改變了Maven for Spring（到3.0.7），Hibernate（到3.6.9）和Spring flex core（到1.5.2）的依賴關係。當我嘗試構建和部署應用程序，我得到的NullPointerException這表明因爲在我的領域類（在堆棧跟蹤的結尾）：

SEVERE: Exception sending context initialized event to listener instance of class  org.springframework.web.context.ContextLoaderListener 
org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBrokerDefaultHandlerMapping': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBroker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NullPointerException 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) 
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291) 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580) 
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895) 
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425) 
    at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:276) 
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:197) 
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47) 
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3972) 
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4467) 
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791) 
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771) 
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:546) 
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:637) 
    at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:563) 
    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:498) 
    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1277) 
    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:321) 
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) 
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053) 
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:785) 
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045) 
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443) 
    at org.apache.catalina.core.StandardService.start(StandardService.java:519) 
    at org.apache.catalina.core.StandardServer.start(StandardServer.java:710) 
    at org.apache.catalina.startup.Catalina.start(Catalina.java:581) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
    at java.lang.reflect.Method.invoke(Method.java:597) 
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) 
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) 
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '_messageBroker': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NullPointerException 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1420) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) 
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291) 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.isSingleton(AbstractBeanFactory.java:396) 
    at org.springframework.context.support.AbstractApplicationContext.isSingleton(AbstractApplicationContext.java:1095) 
    at org.springframework.web.servlet.handler.AbstractUrlHandlerMapping.registerHandler(AbstractUrlHandlerMapping.java:294) 
    at org.springframework.web.servlet.handler.SimpleUrlHandlerMapping.registerHandlers(SimpleUrlHandlerMapping.java:129) 
    at org.springframework.web.servlet.handler.SimpleUrlHandlerMapping.initApplicationContext(SimpleUrlHandlerMapping.java:103) 
    at org.springframework.context.support.ApplicationObjectSupport.initApplicationContext(ApplicationObjectSupport.java:119) 
    at org.springframework.web.context.support.WebApplicationObjectSupport.initApplicationContext(WebApplicationObjectSupport.java:72) 
    at org.springframework.context.support.ApplicationObjectSupport.setApplicationContext(ApplicationObjectSupport.java:73) 
    at org.springframework.context.support.ApplicationContextAwareProcessor.invokeAwareInterfaces(ApplicationContextAwareProcessor.java:106) 
    at org.springframework.context.support.ApplicationContextAwareProcessor.postProcessBeforeInitialization(ApplicationContextAwareProcessor.java:85) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:394) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1413) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) 
    ... 35 more 
Caused by: org.springframework.beans.factory.BeanInitializationException: MessageBroker initialization failed; nested exception is java.lang.NullPointerException 
    at org.springframework.flex.core.MessageBrokerFactoryBean.afterPropertiesSet(MessageBrokerFactoryBean.java:203) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417) 
    ... 54 more 
Caused by: java.lang.NullPointerException 
    at com.educationathome.domain.Device.toString(Device.java:182) 
    at java.lang.String.valueOf(String.java:2826) 
    at java.lang.StringBuilder.append(StringBuilder.java:115) 
    at org.springframework.flex.core.io.PropertyProxyUtils.getBeanPropertyNames(PropertyProxyUtils.java:71) 
    at org.springframework.flex.core.io.PropertyProxyUtils.findPropertyNames(PropertyProxyUtils.java:80) 
    at org.springframework.flex.core.io.SpringPropertyProxy.proxyFor(SpringPropertyProxy.java:85) 
    at org.springframework.flex.core.io.AbstractAmfConversionServiceConfigProcessor.registerAmfProxies(AbstractAmfConversionServiceConfigProcessor.java:115) 
    at org.springframework.flex.core.io.AbstractAmfConversionServiceConfigProcessor.processAfterStartup(AbstractAmfConversionServiceConfigProcessor.java:73) 
    at org.springframework.flex.core.MessageBrokerFactoryBean.processAfterStart(MessageBrokerFactoryBean.java:315) 
    at org.springframework.flex.core.MessageBrokerFactoryBean.afterPropertiesSet(MessageBrokerFactoryBean.java:177) 
    ... 56 more 

我明白任何支持的答覆。

Answer 1

它來自於你的代碼：

com.educationathome.domain.Device.toString(Device.java:182) 

因此檢查這條線，並檢查什麼可以爲空。