rapoo.coder rapoo.coder - 2 months ago 14
Java Question

Spring 4.1 @Qualifier doesnt'work

I have classes, xml configuration file and error stack trace like this. I have no idea why @Qualifier doesn't work. I see on errors that he don't even do anything.

DOG

public class SimpleDog implements Dog {
@Autowired
@Qualifier("small")
private Size size;
private String name;

public Size getSize() {
return size;
}

public void setSize(Size size) {
this.size = size;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public void giveSound() {
System.out.println("dog size is : width : (" + size.getWidth() + ") , height : (" + size.getHeight() + ")");
System.out.println("dog's name : " + name);
}


}

TEST CLASS

public class Test2 {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-test2.xml");
SimpleDog dog = (SimpleDog) context.getBean("dog");
dog.giveSound();
}


}

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.xsd">

<bean id="dog" class="com.tests.test2.SimpleDog">
<property name="name" value="Puppy" />
</bean>

<bean id="size1" class="com.tests.test2.Size">
<qualifier value="small"/>
<property name="height" value="2"/>
<property name="width" value="1"/>
</bean>

<bean id="size2" class="com.tests.test2.Size">
<qualifier value="large"/>
<property name="height" value="20"/>
<property name="width" value="10"/>
</bean>

<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
</beans>


Error Stack Trace

WARNING: Exception encountered during context initialization - cancelling refresh attempt
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dog': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.tests.test2.Size com.tests.test2.SimpleDog.size; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1204)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:725)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:140)
at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:84)
at pl.patrykgryta.test2.Test2.main(Test2.java:12)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.tests.test2.Size com.tests.test2.SimpleDog.size; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
... 18 more
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1016)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:904)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
... 20 more

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dog': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.tests.test2.Size com.tests.test2.SimpleDog.size; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1204)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:538)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:229)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:725)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:140)
at org.springframework.context.support.FileSystemXmlApplicationContext.<init>(FileSystemXmlApplicationContext.java:84)
at pl.patrykgryta.test2.Test2.main(Test2.java:12)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.tests.test2.Size com.tests.test2.SimpleDog.size; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
... 18 more
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.tests.test2.Size] is defined: expected single matching bean but found 2: size1,size2
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1016)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:904)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
... 20 more


Need help

zmf zmf
Answer

@Qualifier is used to reference a bean by its name or id. Since it can't find an xml entry that has a name or id of 'small' it tries to match by type, of which it found two instances of Size.

The following would work:

  <bean id="small" class="com.tests.test2.Size">      
    <property name="height" value="2"/>
    <property name="width" value="1"/>
</bean>

Though it appears you would like to treat instances of Size as pre-configured beans. If that were the case you could declare instances of Dog in your xml file and refer to Size beans ... something like this:

  <bean id="rex" class="com.tests.test2.SimpleDog">
     <property name="name" value="Puppy" />
     <property name="size" ref="size1"/>
  </bean>