java.lang.IllegalStateException: BeanFactory not initialized or already closed - call 'refresh' before accessing beans via the A

      全部的错误信息是这样的Exception in thread "main" java.lang.IllegalStateException: BeanFactory not initialized or already closed - call 'refresh' before accessing beans via the ApplicationContext at org.springframework.context.support.AbstractRefreshableApplicationContext.getBeanFactory(AbstractRefreshableApplicationContext.java:171) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1075) at Main.main(Main.java:11) 大概看一下错误信息：BeanFactory没有实例化或者已经关闭。为啥呢？？原因很简单：ApplicationContext ctx = new ClassPathXmlApplicationContext();Spring实例化BeanFactory的时候是默认到classPath下面查找名为applicationContext.xml的文件。但是这正是这个错误的原因：ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");如果这样的话就不会出现这样的错误了。

      还有一个错误记录一下Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'test' defined in class path resource [applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [test.Test]: No default constructor found; nested exception is java.lang.NoSuchMethodException: test.Test.<init>() at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:965) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:911) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485) 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.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83) at Main.main(Main.java:9) Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [test.Test]: No default constructor found; nested exception is java.lang.NoSuchMethodException: test.Test.<init>() at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:70) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:958) ... 13 more Caused by: java.lang.NoSuchMethodException: test.Test.<init>() at java.lang.Class.getConstructor0(Class.java:2706) at java.lang.Class.getDeclaredConstructor(Class.java:1985) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:65) ... 14 more 这个错误是因为有Spring实例化的类没有默认的构造方法。加上默认的构造方法就行了。