Spring进阶学习一

Spring配置多个属性值，或者spring装配list、array、set、map等方式时可以使用如下方式，比如，这里有个人会演奏很多的乐器，那么需要有乐器Instrument这个接口，然后定义具体的乐器去实现这个乐器接口，还有一个表演者Performer这个接口，因为不只是只有这一个表演者可能。下面具体讲解

（1）建立表演者接口Performer

package com.springaction.P30;
public interface Performer {
	void perform() ;
}

（2）建立Instrument这个接口

package com.springaction.P40;
public interface Instrument {
	public void play();
}

（3）建立OneManHand（一个多才多艺的表演者）这个类，该类要实现Performer，并且内部维护了乐器Instrument这个对象，一般内部定义个全局属性，都会有相应的set方法，以便xml文件中进行IOC

package com.springaction.P46;
import java.util.Collection;
import java.util.Map;
import com.springaction.P30.Performer;
import com.springaction.P40.Instrument;
public class OneManBand implements Performer{
//对list进行测试
 /*	private Collection<Instrument> instruments;
	public void setInstruments(Collection<Instrument> instruments) {
		this.instruments = instruments;
	}
	@Override
	public void perform() {
		for(Instrument instrument:instruments) {
			instrument.play();
		}
	}*/
	private Map<String,Instrument> instruments;
	public void setInstruments(Map<String,Instrument> instruments) {
		this.instruments = instruments;
	}
	@Override
	public void perform() {
		for(String key:instruments.keySet()) {
			System.out.println(key+" :");
			Instrument instrument = instruments.get(key);
			instrument.play();
		}
	}
}

（4）编辑Spring的xml文件，将上面的类OneManHand注入到bean中

<?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-3.0.xsd">
<bean id="sonnet29" class="com.springaction.P34.Sonnet29">
</bean>
<bean id="duck" class="com.springaction.P30.PoeticJuggler">
    <constructor-arg value="15"></constructor-arg>
    <constructor-arg ref="sonnet29"></constructor-arg>
    <!--     <constructor-arg value="小名"></constructor-arg>-->
</bean>
<bean id="kenny" class="com.springaction.P40.Instrumentalist">
    <property name="song" value="我爱你中国"></property>
    <property name="instrument" ref="saxophone"></property>
</bean>
<bean id="saxophone" class="com.springaction.P40.Saxophone">
</bean>
<!-- List测试代码部分
<bean id="hank" class="com.springaction.P46.OneManBand">
    <property name="instruments">
        <list>
            <ref bean="guitar"/>
            <ref bean="cymbal"/>
            <ref bean="hormonica"/>
        </list>
    </property>
</bean>
-->
<bean id="hank" class="com.springaction.P46.OneManBand">
    <property name="instruments">
        <map>
            <entry key="GUITAR" value-ref="saxophone"></entry>
            <entry key="CYMBAL" value-ref="saxophone"></entry>
            <entry key="HARMONICA" value-ref="saxophone"></entry>
        </map>
    </property>
</bean>
</beans>

（5）测试代码部分

package com.springaction.P30;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class PerformerTest {
	@Test
	public void testPerform() {
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		Performer performer = (Performer)ctx.getBean("duck");
		Performer performer2 = (Performer)ctx.getBean("hank");
		performer.perform();
		performer2.perform();
	}
}

（6）结果展示：

GUITAR :
Ding Ding Ding
CYMBAL :
Ding Ding Ding
HARMONICA :
Ding Ding Ding