@Autowired注解不起作用，求指点

[喝可乐怕蛀牙]

package com.yangwan.beans;

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

public class AutoWirePro {
	
	@Autowired
	private Car car;
	@Autowired
	private Bicycle bicycle;
	public void printAutoWireProInformation(){
		car.printCarInformation();
		bicycle.printBicycleInformation();
	}
}

配置文件代码

<?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">
    <context:annotation-config />
    <context:component-scan base-package="com.yangwan.beans" />
    <bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>
   <!-- 利用构造函数带参数的索引式方法注入bean
    <bean id="car" class="com.yangwan.beans.Car">
    	<constructor-arg index="0" value="大众"></constructor-arg>
    	<constructor-arg index="1" value="88888"></constructor-arg>
    </bean>
     -->
     <bean id="autowirepro" class="com.yangwan.beans.AutoWirePro"/>
     <bean id="car" class="com.yangwan.beans.Car">
     <constructor-arg type="double" value="333233"></constructor-arg>
    	<constructor-arg type="String" value="大众"></constructor-arg>
    </bean>
    <bean id="bicycle" class="com.yangwan.beans.Bicycle">
    	<property name="brand" value="Ferfly"></property>
    	<property name="price" value="389.4"></property>
    </bean>
    <bean id="carstaticfactory" class="com.yangwan.beans.CarFactory" factory-method="getInstance">
		<constructor-arg index="0" value="奥迪"></constructor-arg>    
		<constructor-arg index="1" value="78872"></constructor-arg>
    </bean>
    <!-- 定义实例工厂 -->
    <bean id="bicycleinstancefactory" class="com.yangwan.beans.BicycleInstanceFactory"></bean>
    <!-- 利用实例工厂创建bean -->
    <bean id="bicycleinstance" factory-bean="bicycleinstancefactory" factory-method="getInstance">
    	<constructor-arg index="0" value="HariErfi"></constructor-arg>    
		<constructor-arg index="1" value="899"></constructor-arg>
    </bean>
    <bean id="requiredEntity" class="com.yangwan.beans.RequiredEntity">
    </bean>
</beans>

测试代码：
public class Main {
public static void main(String[] args) {
Resource resource = new FileSystemResource("src/main/resources/spring/application-config.xml");
BeanFactory beanFactory = new XmlBeanFactory(resource);
Car tempCar = beanFactory.getBean("car",Car.class);
tempCar.printCarInformation();
Bicycle bicycle = beanFactory.getBean("bicycle",Bicycle.class);
bicycle.printBicycleInformation();
RequiredEntity requiredEntity = beanFactory.getBean("requiredEntity",RequiredEntity.class);
requiredEntity.printEntityInformation();
AutoWirePro autoWirePro = beanFactory.getBean("autowirepro",AutoWirePro.class);
autoWirePro.printAutoWireProInformation();
}

}

输出结果:
brand: 大众 price: 333233.0
brand: Ferfly price: 389.4
name : null
number: 0
Exception in thread "main" java.lang.NullPointerException
at com.yangwan.beans.AutoWirePro.printAutoWireProInformation(AutoWirePro.java:12)
at com.yangwan.test.Main.main(Main.java:28)

原因是car和bicycle对象没有被实例化都是null.感觉是配置问题。包括加上
<context:annotation-config />
<context:component-scan base-package="com.yangwan.beans" />
等，均没有效果。

[李德胜1995]

这样写吧

ApplicationContext app=new ClassPathXmlApplicationContext("classpath:xml文件路径名称");
		System.out.println(app==null);
		AutoWirePro car=app.getBean(AutoWirePro.class);
		car.printAutoWireProInformation();

[userLiangjunjie]

有提供get，set方法么

[_jant]

把get set方法加上就可以了

[podd]

要有实体类，加上get,set

[X元素]

@Autowired 是不需要get set的， @Autowired private Car car; @Autowired private Bicycle bicycle; 这两个bean对象是需要声明成bean的。实体对象上加上@Service 试试

[明悟]

你在类AutoWirePro 上加@Service注解，把配置文件的 <bean id="autowirepro" class="com.yangwan.beans.AutoWirePro"/> 去掉就没问题了

[明悟]

不能对同一个bean 实例化用配置式，属性注入用注解式

[vkqiang]

要有实体类，加上get,set

[podd]

引用 8 楼 vkqiang 的回复:

要有实体类，加上get,set

这是我很不负责任的一次回答

[953384951]

楼主，你既然用扫描的方法，那你干嘛不在实体类上注释你要的值呢？非得要xml文件上配置?

[喝可乐怕蛀牙]

1楼的方法是正确的，我之前使用Resource获得配置文件，然后根据resource来创建BeanFactory，根据BeanFactory依据id从ioc容器获取beans实例。代码表面上看没有错，但是假如@Autowire注解后，老是发现注解不起作用，IOC容器并不能自动创建实例。 Resource resource = new FileSystemResource("配置文件路径"); BeanFactory beanFactory = new XmlBeanFactory(resource); Bean bean = beanFacotory.getBean("bean_id",Bean.class); 改用1楼的的方法，使用ApplicationContext来获取IOC容器返回beans实例，这个问题获得解决。 String[] locations = {"file:C:/Users/bw/Desktop/yw/AutowireTestPro/src/main/resources/spring/application-config.xml"}; ApplicationContext ctx = new ClassPathXmlApplicationContext(locations); Bean bean = (Bean)ctx.getBean("bean_id"); 感谢。不过具体原因还不是很清楚，还有就是ClassPathXmlApplicationContext中classpath的相对路径我还是不清楚，我的工程结构是maven的，还在研究！