Spring 4.1 @Qualifier doesnt'work

Question

I have classes, an xml configuration file, and an error stack trace like this. I have no idea why @Qualifier is not working. I see from mistakes that he doesn’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 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

Help is needed

Answer 1

@Qualifier is used to refer to a bean by its name or identifier. Since he cannot find an xml entry that has the name or identifier "small", it tries to match by type from which it found two instances of Size.

The following steps will work:

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

, , Size beans. , Dog xml Size beans... :

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

Answer 2

, ApplicationContext BeanFactory AutowireCandidateResolver (.. SimpleAutowireCandidateResolver) QualifierAnnotationAutowireCandidateResolver.

Spring ( 4.0), QualifierAnnotationAutowireCandidateResolver ApplicationContexts ( AbstractRefreshableApplicationContext.customizeBeanFactory(DefaultListableBeanFactory)).

QualifierAnnotationAutowireCandidateResolver AppCtx / :

• org.springframework.beans.factory.annotation.CustomAutowireConfigurer (. javadoc postProcessBeanFactory(ConfigurableListableBeanFactory)), . xml:

  <bean id="customAutowireConfigurer" class="org.springframework.beans.factory.annotation.CustomAutowireConfigurer">
  <property name="customQualifierTypes">
      <set>
          <value>org.springframework.beans.factory.annotation.Qualifier</value>
      </set>
  </property>
  

• <context:annotation-config /> (. AnnotationConfigBeanDefinitionParser.parse(Element,ParserContext) )

Answer 3

@Qualifier (name= ".." ) bean, Spring,

beans - size1 size2.

   @Qualifier("size1")

Answer 4

@Qualifier ( "small" ) , bean "small" (bean id = "small" ...) @Autowired , bean , .

. : bean, , bean . .

Spring , "" xml, . NO id = "..." , , id. ( ), , id = "sizeX"

Answer 5

stacktrace

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

Spring bean, 2 beans, , .

, BeanFactory bean , bean.

, bean id="small"

@Qualifier("small") @Qualifier("size1") @Qualifier("size2").

Answer 6

Spring 4.x XML, :

xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"

:

<context:component-scan base-package="com.tests.test2" />

, 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" xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.tests.test2" />

    <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>
</beans>

.

Answer 7

1.x, Spring 3.x . Spring 3- > 4 struts . Spring 3 4, , .

reason1: QualifierAnnotationAutowireCandidateResolver Spring 4

Spring 3, beanfacotry , Spring :

beanFactory.setAutowireCandidateResolver(new QualifierAnnotationAutowireCandidateResolver());

Spring 4 AbstractRefreshableApplicationContexts

protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory)

, () , config xml. "SimpleAutowireCandidateResolver

reason2: 'isAutowireCandidate() Spring 4s DefaultListableBeanFactory

isAutowireCandidate() beanFactory, .

Spring 3, , isAutowireCandidate(). Spring 4 . , isAutowireCandidate(). , ContextAnnotationAutowireCandidateResolver, QualifierAnnotationAutowireCandidateResolver , - .

The @ a5phyx solution should work if it is added to a child’s xml code .

Answer 8

Try using this bean definition in beans.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:security="http://www.springframework.org/schema/security"
    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
        http://www.springframework.org/schema/security
        http://www.springframework.org/schema/security/spring-security.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd"
        xmlns:context="http://www.springframework.org/schema/context">

    <context:annotation-config/>
    <!-- define your beans here-->
</beans>