SpringInAction--自动化装配Bean（显示装配之xml配置）

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Spring在配置时候有三种方案可选

1、在xml中进行显示配置

2、在java中进行显示配置

3、隐式的Bean发现机制和自动装配

今天学习的第一种—— 在xml中进行显示配置

老规矩先创建 CompactDisc 接口，DangNianQing 单首CD碟子，指定播放的CD碟子类 RandomCd 还有播放器 CDPlay

CompactDisc

package com.bean.xml;/**
* Created by IntelliJ IDEA.
* Author XueYuan
* Data 2017/02/22
* Time 14:06
*/public interface CompactDisc {
void play();
}

DangNianQing

package com.bean.xml;/**
* Created by IntelliJ IDEA.
* Author XueYuan
* Data 2017/02/22
* Time 14:07
*/public class DangNianQing implements CompactDisc { private String title = "DangNianQing";
private String artist = "张国荣"; public void play() {
System.out.println("Playing " + title + " By " + artist);
}
}

RandomCd

package com.bean.xml;/**
* Created by IntelliJ IDEA.
* Author XueYuan
* Data 2017/02/22
* Time 14:33
*/public class RandomCd implements CompactDisc { private String title;
private String artist; public RandomCd(String title, String artist) {
this.title = title;
this.artist = artist;
} public void play() {
System.out.println("Playing " + title + " By " + artist);
}}

CDPlay

package com.bean.xml;import org.springframework.beans.factory.annotation.Autowired;/**
* Created by IntelliJ IDEA.
* Author XueYuan
* Data 2017/02/22
* Time 14:23
*/public class CDPlay { private CompactDisc compactDisc; @Autowired // set注入
public void setCompactDisc(CompactDisc compactDisc) {
this.compactDisc = compactDisc;
} //构造器注入
/*public CDPlay(CompactDisc compactDisc) {
this.compactDisc = compactDisc;
}*/ public void play() {
compactDisc.play();
}}

好了，东西准备好了，下面就看准备操作了，需要建立一个配置的xml文件

装配bean 即准备好单张曲子的那个cd碟

装配bean 即准备好指定点歌的的那个cd碟

<bean id="cdPlay" class="com.bean.xml.CDPlay">



<property name="compactDisc" ref="randomCd" />
</bean>

配置bean 即要播放一首歌的cd碟子呢还是要播放可以指定歌曲的碟子呢!

这边可以看出有多个选择如果是set注入的话就是上面的，如果是构造器注入的话，就是下面的代码（红色部分）

<bean id="cdPlay" class="com.bean.xml.CDPlay">


<constructor-arg ref="randomCd"/>

</bean>

整体代码如下：

<?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"> 
<bean id="dangNianQing" class="com.bean.xml.DangNianQing"/> 
<bean id="cdPlay" class="com.bean.xml.CDPlay">



<property name="compactDisc" ref="randomCd" />
</bean> <bean id="randomCd" class="com.bean.xml.RandomCd">
<constructor-arg index="0" value="当年情"/>
<constructor-arg index="1" value="张国荣"/>
</bean>
</beans>

好了都碟子选好了，也放入播放器了，下面就要按下开始播放按钮看是否可以播放了

package com.bean.xml;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;/**
* Created by IntelliJ IDEA.
* Author XueYuan
* Data 2017/02/22
* Time 14:08
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(value = "config.xml")
public class CDPlayerTest { /*@Autowired
DangNianQing dangNianQing;*/ @Autowired
CDPlay cdPlay; @Test
public void play() {
cdPlay.play();
}
}