Spring找不到bean並拋出NoSuchBeanDefinitionException

Question

我對實現Spring in Action程序示例有疑問。

測試類別：

@Test
public void testBasicUsage() throws PerformanceException {
    ApplicationContext context = new ClassPathXmlApplicationContext("/**/java/springidol/spring-idol.xml");
    Performer performer = (Performer) context.getBean("juggler");
    performer.perform();
}

應該由Spring配置的Juggler類

public class Juggler implements Performer {

    private int beanBags = 3;

    public Juggler() {
    }

    public Juggler(int beanBags) {
        this.beanBags = beanBags;
    }

    @Override
    public void perform() throws PerformanceException {
        System.out.println("JUGGLING " + beanBags + " BEANBAGS");
    }
}

以及此bean的xml配置文件：

<?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="juggler"
          class="springidol.Juggler">
        <constructor-arg value="15"/>
    </bean>
</beans>

這段代碼拋出NoSuchBeanDefinitionException：

Aug 30, 2018 1:20:43 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1c53fd30: startup date [Thu Aug 30 13:20:43 EEST 2018]; root of context hierarchy

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'juggler' available

    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:686)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1210)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1089)
    at springidol.TestMain.testBasicUsage(TestMain.java:12)

Answer 1

我認為您在ClassPathXmlApplicationContext提供的類路徑應該是當前XML配置所在的位置。 類路徑上的文件會自動掃描，我們只需要提供文件夾路徑即可。 嘗試在Test類中進行以下更改：

ApplicationContext context = new ClassPathXmlApplicationContext("java/springidol/spring-idol.xml");

參考： Spring Source