实现自动装配需要用注解：注解分为 spring规范和java规范 ，java规范需要引入javax.inject 包 ，使用maven，直接引入。
从中可以看到 @Named @Inject属于java规范，@Component @Autowired @Resource属于spring注解
@Named大致等效于@Component 而@Inject和@Autowired也相似，但是@Inject要强制注入，@Autowired(required=false)可以选择略过不报异常
实例：
1.写个bean接口
package test.soundsystem;public interface CompactDisc {void play();}
2.实现接口
package test.soundsystem;import javax.inject.Named;@Namedpublic class SgtPeppers implements CompactDisc {private String title="Sgt. Pepper's Lonely Hearts Club Band";private String artist = "The Beatles";public void play() {System.out.println("Playing "+title+" by "+artist);}}
3.自动装配类
package test.soundsystem;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;import test.voice.Book;@Configuration@ComponentScan(basePackageClasses={Book.class,CompactDisc.class})public class CDPlayerConfig {}
4.测试类：
package test.soundsystem;import javax.inject.Inject;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import test.voice.Book;@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes=CDPlayerConfig.class)public class CDPlayerTest {@Autowiredprivate CompactDisc cd;@Injectprivate Book book;@Testpublic void cdShouldNotBeNull(){cd.play();book.read();}}
测试结果：
