（待解答）Spring报错：Exception in thread "main" org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'car' is defined

 1 package com.tt.spring.beans;
 2 
 3 public class HelloWorld {
 4     
 5     private String name;
 6 
 7     public void setName(String name) {
 8         System.out.println("hello: "+ name);
 9         this.name = name;
10     }
11     
12     public void hello(){
13         System.out.println("hello: " + name);
14     }
15 
16     public HelloWorld() {
17         System.out.println("HelloWorld‘s Constructor");
18     }
19 
20     
21 }

 1 package com.tt.spring.beans;
 2 
 3 public class Car {
 4 
 5     private String brand;
 6     private String corp;
 7     private int price;
 8     private int maxSpeed;
 9     
10     
11     public Car() {
12         System.out.println("Car‘s Constructor");
13     }
14 
15     public Car(String brand, String corp, int price) {
16         super();
17         this.brand = brand;
18         this.corp = corp;
19         this.price = price;
20     }
21 
22     @Override
23     public String toString() {
24         return "Car [brand=" + brand + ", corp=" + corp + ", price=" + price + ", maxSpeed=" + maxSpeed + "]";
25     }
26     
27 }

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xmlns:context="http://www.springframework.org/schema/context"  
 5     xsi:schemaLocation="http://www.springframework.org/schema/beans 
 6                         http://www.springframework.org/schema/beans/spring-beans.xsd
 7                         http://www.springframework.org/schema/context/spring-context.xsd
 8                         http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 9                         
10    <context:component-scan base-package="com.tt.spring.beans"></context:component-scan>
11     <!--
12                      配置bean 
13         class:bean的全类名，通过反射的方式在IOC容器中创建Bean实例，所以要求Bean中必须有无参的构造器
14         id:标识容器中的bean，id唯一
15     -->
16     <bean id="helloWorld" class="com.tt.spring.beans.HelloWorld">
17          <property name="name" value="Spring"></property>
18     </bean>   
19     
20     <!-- 通过构造方法来配置bean的属性 -->
21     <bean id="car" class="com.tt.spring.beans.Car">
22          <constructor-arg value="Audi"></constructor-arg>
23          <constructor-arg value="chengdu"></constructor-arg>
24          <constructor-arg value="30000"></constructor-arg>
25     </bean>
26     
27 </beans>

 1 package com.tt.spring.beans;
 2 
 3 import org.springframework.context.ApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 public class Main {
 7 
 8     public static void main(String[] args){
 9         /*
10         //创建HelloWorld的一个对象
11         HelloWorld helloWorld = new HelloWorld();
12         //为name属性赋值
13         helloWorld.setName("tt");
14         */
15         //调用hello方法
16         
17         //1.创建Spring 的 IOC 容器对象
18         //ApplicationContext代表 IOC 容器
19         //ClassPathXmlApplicationContext:是ApplicationContext 接口的实现类，该实现类从类路径下来加载配置文件。
20         ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
21         
22         //2.从IOC容器中获取Bean实例
23         //利用id定位到IOC容器中的bean
24         HelloWorld helloWorld = (HelloWorld) ctx.getBean("helloWorld");
25     
26         //利用类型返回 IOC容器中的Bean，但要求 IOC 容器中必须只能有一个该类型的Bean
27         //HelloWorld helloWorld = ctx.getBean(HelloWorld.class);
28         
29          System.out.println(helloWorld);
30         
31         //3.调用Hello方法
32         //helloWorld.hello();
33         
34         Car car = (Car) ctx.getBean("car");
35         //Car car = ctx.getBean(Car.class);
36         System.out.println(car);
37     
38     }
39 }