Question

我正在制作一个简单的程序来测试内部bean但是获得异常。这是我写的代码。

TextEditor类：

public class TextEditor {

private SpellChecker spellChecker;

public SpellChecker getSpellChecker() {
    return spellChecker;
}

public void setSpellChecker(SpellChecker spellChecker) {
    this.spellChecker = spellChecker;
}

public void spellCheck(){
    spellChecker.spellChecking();
}
}

SpellChecker类：

public class SpellChecker {

public SpellChecker() {
    System.out.println("Spell Checker Constructor");
}

public void spellChecking(){
    System.out.println("Spell Checking");
}
}

控制器类：

public class Controller {

public static void main(String[] args) {
    ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
    TextEditor editor = (TextEditor)context.getBean("editor");
    editor.spellCheck();
}
}

spring.xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

 <bean id="editor" class="com.data.TextEditor">
    <property name="spellChecker">
        <bean id="spellChecker" name="com.data.SpellChecker"/>
    </property>
</bean>

堆栈跟踪：

WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'editor' defined in class path resource [spring.xml]: Cannot create inner bean 'spellChecker' while setting bean property 'spellChecker'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'spellChecker' defined in class path resource [spring.xml]: Instantiation of bean failed; nested exception is java.lang.IllegalStateException: No bean class specified on bean definition
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'editor' defined in class path resource [spring.xml]: Cannot create inner bean 'spellChecker' while setting bean property 'spellChecker'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'spellChecker' defined in class path resource [spring.xml]: Instantiation of bean failed; nested exception is java.lang.IllegalStateException: No bean class specified on bean definition
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:313)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:122)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1481)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1226)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
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:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
at com.controller.Controller.main(Controller.java:17)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'spellChecker' defined in class path resource [spring.xml]: Instantiation of bean failed; nested exception is java.lang.IllegalStateException: No bean class specified on bean definition
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1050)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:299)
... 15 more
Caused by: java.lang.IllegalStateException: No bean class specified on bean definition
at org.springframework.beans.factory.support.AbstractBeanDefinition.getBeanClass(AbstractBeanDefinition.java:356)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:66)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1098)
... 19 more

这是我写的所有代码都可以告诉我在这里做的错误是什么。我会感激的。

Answer 1

 <bean id="spellChecker" name="com.data.SpellChecker"/>

将属性名称更改为属性类

Answer 2

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

 <bean id="editor" class="com.data.TextEditor">
    <property name="spellChecker">
        <bean class="com.data.SpellChecker"/>
    </property>
</bean>

Answer 3

将属性名称更改为属性类

这将解决您的问题

<!-- Definition for textEditor bean using inner bean -->
  <bean id="textEditor" class="com.tutorialspoint.TextEditor">
    <property name="spellChecker">
       <bean id="spellChecker" class="com.tutorialspoint.SpellChecker"/>
    </property>
  </bean>

Answer 4

Bean定义缺少class属性。添加它：

<bean id="spellChecker" name ="com.data.SpellChecker" class="com.data.SpellChecker"/>

使用innerBean时出错

4 个答案: