用xml配置bean时显示以下错误是什么原因？

Question

The prefix "c" for attribute "c:_-ref" associated with an element type "bean

************定义一个接口********************

package beanConfigByXml;

• public interface CompactDisc {
• 
  
• void play();
• }

************实现类1********************

package beanConfigByXml;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
public class CDPlayer implements CompactDisc{

• @Autowired
• private CompactDisc cd;
• @Override
• public void play() {
• cd.play();
• 
  
• }

}

************实现类2********************

package beanConfigByXml;
import org.springframework.stereotype.Component;

• public class SgtPeppers implements CompactDisc{
• private String title="Sgt.Pepper's Lonely Hearts Club Band";
• private String artist="The Beatles";
• @Override
• public void play() {
• // TODO Auto-generated method stub
• System.out.println("Playing"+title+"by"+artist);
• }
• }

********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
• http://www.springframework.org/schema/context">
• 
  
• <bean class="beanConfigByXml.SgtPeppers"
  
• c:_-ref="sgtPeppers" />
• <bean class="beanConfigByXml.CDPlayer"
• c:_-ref="cdPlayer" />
• <!-- -->

***********测试代码*************

package beanConfigByXml;
import static org.junit.Assert.assertNotNull;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

• @RunWith(SpringJUnit4ClassRunner.class)
• public class CDPlayerTest {
• @Autowired
• private CompactDisc cd;
• @Test
• public void cdShouldNotBeNull() {
• cd.play();
• assertNotNull(cd);
• }

xml配置就报错误，刚接触Spring,大神们看看~
The prefix "c" for attribute "c:_-ref" associated with an element type "bean

Answer 1

bean标签没有c:_-ref这个属性吧