有以下三种配置 在xml中配置 在java中配置 bean自动装配

自动装配

这里以转载CD为例子

首先需要建立CD概念

即，定义一个cd接口

只需要实现添加两个注解，

package com.ming; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; /** * 定义cd接口 * @author ming */ @Configuration @ComponentScan public interface CompactDisc { /** * 规定方法为play */ void play(); } package com.ming; import org.springframework.stereotype.Component; /** * * @author ming */ // 启用组件扫描 @Component class SgtPeppers implements CompactDisc { private String title = "标题"; private String artist = "内容"; /** * 规定方法为play */ @Override public void play() { System.out.println(this.artist + this.title); } } package com.ming; import org.junit.After; import org.junit.Before; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import static org.junit.Assert.*; public class CompactDiscTest { private ApplicationContext applicationContext = null; @Before public void setUp() throws Exception { applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml"); } @After public void tearDown() throws Exception { } @Test public void play() { CompactDisc compactDisc = applicationContext.getBean(CompactDisc.class); assertNotNull(compactDisc); } }

扫描的时候，会直接按照该类所在的包，作为基础包，进行扫描

对依赖的实现自动装配

添加注解以后，初始化bean以后，会尽可能的满足bean的依赖

目录如下

package com.ming; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; /** * * @author ming */ @Component public class CDPlay implements MediaPlayer { CompactDisc compactDisc = null; @Autowired public CDPlay(CompactDisc compactDisc){ this.compactDisc = compactDisc; } /** * 规定方法为play */ @Override public void play() { compactDisc.play(); } } package com.ming; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; /** * 定义cd接口 * @author ming */ @Configuration @ComponentScan public interface CompactDisc { /** * 规定方法为play */ void play(); } package com.ming; import org.springframework.context.annotation.ComponentScan; /** * @author ming */ @ComponentScan public interface MediaPlayer { /** * 规定方法为play */ public void play(); } package com.ming; import org.springframework.stereotype.Component; /** * * @author ming */ // 启用组件扫描 @Component class SgtPeppers implements CompactDisc { private String title = "标题"; private String artist = "内容"; /** * 规定方法为play */ @Override public void play() { System.out.println(this.artist + this.title); } } <?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.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <context:component-scan base-package="com.ming"/> </beans> package com.ming; import org.junit.After; import org.junit.Before; import org.junit.Rule; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import static org.junit.Assert.*; public class CompactDiscTest { private ApplicationContext applicationContext = null; @Before public void setUp() throws Exception { applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml"); } @After public void tearDown() throws Exception { } @Test public void play() { MediaPlayer mediaPlayer = (MediaPlayer) applicationContext.getBean(MediaPlayer.class); mediaPlayer.play(); assertNotNull(mediaPlayer); } }

运行结果

在这里，在装配的时候，尽量满足配置规则进行装配

Java代码装配bean

package com.ming; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * * @author ming */ @Configuration // 注解表明这是一个配置类 public class CDPlayerConfig { @Bean public CompactDisc sgtPeppers(){ // 此处进行装配 return new SgtPeppers(); } /** * 注入装配 * @return */ @Bean public CDPlay cdPlay(){ return new CDPlay(this.sgtPeppers()); } }