Question

我正在使用Springs framework 3.2.0。而且我无法使用@component注释。下面是我执行Test.java时收到的错误。我尝试更改java版本，并弹出框架版本但没有任何效果。

的beans.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:p="http://www.springframework.org/schema/p"
    xmlns:c="http://www.springframework.org/schema/c"  
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:util="util-namespace"  
    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">
    <context:annotation-config />
    <context:component-scan base-package="com.ds.cab.car" />


    <bean id="e" class="com.ds.cab.engine.Engine">
        <property name="modelyear" value="2015 AUDI"></property>
    </bean>
</beans>

Car.java

package com.ds.cab.car;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.ds.cab.engine.Engine;

@Component
public class Car {
    @Autowired
    private Engine engine;

    public void setEngine(Engine engine) {
        this.engine = engine;
    }

    public void printData() {
        // TODO Auto-generated method stub
        System.out.println("Engine model year: "+engine.getModelyear());
    }
}

Engine.java

package com.ds.cab.engine;

public class Engine {
    private String modelyear;

    public void setModelyear(String modelyear) {
        this.modelyear = modelyear;
    }
    public String getModelyear() {
        return modelyear;
    }
}

Test.java

package ioc;

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

import com.ds.cab.car.Car;

public class Test {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("Beans.xml");
        Car c = (Car)ctx.getBean(Car.class);
        c.printData();
    }
}

错误

Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: file [E:\Prakhar\STS Workspace\StereoTyping01\bin\com\ds\cab\car\Car.class]; nested exception is java.lang.IllegalArgumentException
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:281)
    at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:242)
    at org.springframework.context.annotation.ComponentScanBeanDefinitionParser.parse(ComponentScanBeanDefinitionParser.java:84)
    at org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(NamespaceHandlerSupport.java:73)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1435)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1425)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:184)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:140)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:111)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:493)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:174)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:209)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:180)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:243)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:127)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:93)
    at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:131)
    at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:537)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:451)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at ioc.Test.main(Test.java:10)
Caused by: java.lang.IllegalArgumentException
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at org.springframework.asm.ClassReader.<init>(Unknown Source)
    at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:52)
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:80)
    at org.springframework.core.type.classreading.CachingMetadataReaderFactory.getMetadataReader(CachingMetadataReaderFactory.java:101)
    at org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider.findCandidateComponents(ClassPathScanningCandidateComponentProvider.java:257)
    ... 24 more

Answer 1

创建一个Car bean并将引擎bean注入其中（e表示您的引擎bean名称）：

<bean id="Car" class = "com.ds.cab.car.Car">
    <constructor-arg ref="e"/>
</bean>

Answer 2

在beans.xml中，

将组件扫描更改为

<context:component-scan base-package="com.ds.cab.car" />
删除引擎bean声明。
将@Component注释添加到Car Class。

@Component Springs注释不起作用

2 个答案: