斯普林斯資格賽錯誤

Question

我正在學習斯普林斯，同時學習@Autowiring，碰到@Qualifier。我已經聲明瞭一個限定符，但仍然有一個拋出的異常。

下面是我的代碼

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" xmlns:context="http://www.springframework.org/schema/context" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 


    <bean id="pointA" class="org.xyz.practice.Point"> 
     <qualifier value="myCircle" /> 
     <constructor-arg index="0" value="${pointA.pointX}"></constructor-arg> 
     <constructor-arg index="1" value="${pointA.pointY}"></constructor-arg> 
    </bean> 

    <bean id="pointB" class="org.xyz.practice.Point"> 
     <constructor-arg index="0" value="${pointA.pointX}"></constructor-arg> 
     <constructor-arg index="1" value="${pointA.pointY}"></constructor-arg> 
    </bean> 

    <bean 
     class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> 
     <property name="locations" value="configurations.properties"></property> 
    </bean> 



    <bean id="circle" class="org.xyz.practice.Circle"> 

    </bean> 

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


</beans> 

Circle.java：

package org.xyz.practice; 

import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.beans.factory.annotation.Qualifier; 

public class Circle implements Shape { 

    private Point center; 

    public Point getCenter() { 
     return center; 
    } 

    @Autowired 
    @Qualifier("myCircle") 
    public void setCenter(Point center) { 
     this.center = center; 
    } 

    @Override 
    public void draw() { 
     System.out.println("Drawing a circle..."); 
     System.out.println("Circle point si (" + center.getX() + " , " + center.getY() + ")"); 
    } 

} 

MainClass：

package org.xyz.practice; 

import org.springframework.context.ApplicationContext; 
import org.springframework.context.support.ClassPathXmlApplicationContext; 

public class DrawingApp { 

    public static void main(String[] args) { 

     ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml"); 
     Shape shape = (Shape) context.getBean("circle"); 
     shape.draw(); 
    } 

} 

例外：

WARNING: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'circle': Unsatisfied dependency expressed through method 'setCenter' parameter 0: No qualifying bean of type [org.xyz.practice.Point] is defined: expected single matching bean but found 2: pointA,pointB; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.xyz.practice.Point] is defined: expected single matching bean but found 2: pointA,pointB 
Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'circle': Unsatisfied dependency expressed through method 'setCenter' parameter 0: No qualifying bean of type [org.xyz.practice.Point] is defined: expected single matching bean but found 2: pointA,pointB; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.xyz.practice.Point] is defined: expected single matching bean but found 2: pointA,pointB 
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:647) 
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) 
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349) 
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) 
    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$1.getObject(AbstractBeanFactory.java:306) 
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) 
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:775) 
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861) 
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) 
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) 
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83) 
    at org.xyz.practice.DrawingApp.main(DrawingApp.java:10) 
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.xyz.practice.Point] is defined: expected single matching bean but found 2: pointA,pointB 
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveNotUnique(DependencyDescriptor.java:172) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1064) 
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1018) 
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:639) 
    ... 15 more 

請不要紀念這個爲@Resource（相關的）問題重複，我想要去一步一步的。在您的參數

Answer 1

完成Spring上下文通過XML通過向圓豆中心屬性配置。

<bean id="circle" class="org.xyz.practice.Circle"> 
    <property name="center" class="package.Point"/> 
</bean> 

您還沒有使用@annotation配置，儘量不要混合使用XML和@annotation配置。如果您想使用該配置，請將組件掃描添加到applicationContext.xml。

<context:component-scan base-package="base.package.to.scan" /> 

Answer 2

認沽預選賽：

@Autowired 
public void setCenter(@Qualifier("myCircle") Point center) { 
    this.center = center; 
}