Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not pub

超、凢脫俗 2022-06-10 07:22 92阅读 0赞

![这里写图片描述][SouthEast]

![这里写图片描述][SouthEast 1]

警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'ELConfig': Unsatisfied dependency expressed through field 'str'; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not public?
    Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'ELConfig': Unsatisfied dependency expressed through field 'str'; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not public?
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
        at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
        at com.yubai.EL.MainEl.main(MainEl.java:7)
    Caused by: org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not public?
        at org.springframework.context.expression.StandardBeanExpressionResolver.evaluate(StandardBeanExpressionResolver.java:164)
        at org.springframework.beans.factory.support.AbstractBeanFactory.evaluateBeanDefinitionString(AbstractBeanFactory.java:1448)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1088)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
        ... 14 more
    Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1008E: Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not public?
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.readProperty(PropertyOrFieldReference.java:226)
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.getValueInternal(PropertyOrFieldReference.java:94)
        at org.springframework.expression.spel.ast.PropertyOrFieldReference.access$000(PropertyOrFieldReference.java:46)
        at org.springframework.expression.spel.ast.PropertyOrFieldReference$AccessorLValue.getValue(PropertyOrFieldReference.java:379)
        at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:88)
        at org.springframework.expression.spel.ast.SpelNodeImpl.getValue(SpelNodeImpl.java:120)
        at org.springframework.expression.spel.standard.SpelExpression.getValue(SpelExpression.java:262)
        at org.springframework.context.expression.StandardBeanExpressionResolver.evaluate(StandardBeanExpressionResolver.java:161)
        ... 18 more
    
    Process finished with exit code 1

错误信息：

Property or field 'str' cannot be found on object of type 'com.yubai.EL.DemoService' - maybe not public?

1.  str这个属性在’com.yubai.EL.DemoService’中没有找到，意味着可能她是私有的
2.  @Value(“\#\{demoService.str\}”)是通过访问demoService这个bean的所属类的对象的getStr()这个方法的，由于DemoService这个类的属性是私有属性，所以除过本类之外的类访问需要通过getXXX和setXXX方法。所以DemoService类必须提供getXXX方法才可以访问

> 注意：@Value（“ ”）这种访问方式是直接注入到此类的属性中，不通过setXXX方法
> 
> 而在双引号中用\#\{\}这种方式是通过getXXX方法访问获得值
> 
> 然后把值注入到本类的属性中。直接通过对象.属性的方式访问

**解决方法：打开DemoService类中的getXXX方法。如下图：**

![这里写图片描述][SouthEast 2]

[SouthEast]: /images/20220610/f97efc4fa4bb4f7f98b58a3b10456e37.png
[SouthEast 1]: /images/20220610/632b5739575e4201a1d2fbefea87f93c.png
[SouthEast 2]: /images/20220610/93d94a9682f847f7a1bfea31a2806cfa.png