SPEL : Conditionally Evaluating

Song.java:

package com.lnn.spel.conditional;

public class Song {

      private String name = null;

      public String getName() {

            return name;

      }

      public void setName(String name) {

            this.name = name;

      }

}

Instrument.java:

package com.lnn.spel.conditional;

public class Instrument {

      private String name = null;

      private Song song = null;

      public String getName() {

            return name;

      }

      public void setName(String name) {

            this.name = name;

      }

      public Song getSong() {

            return song;

      }

      public void setSong(Song song) {

            this.song = song;

      }

}

Opera.java:

package com.lnn.spel.conditional;

public class Opera {

      private Instrument instrument;

      public Instrument getInstrument() {

            return instrument;

      }

      public void setInstrument(Instrument instrument) {

            this.instrument = instrument;

      }

}

conditional.xml:

<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="song" class = "com.lnn.spel.conditional.Song">

            <property name="name" value="Jingle Bells..."/>         

      </bean>

      <bean id="song2" class = "com.lnn.spel.conditional.Song">

            <property name="name" value="#{song.name?:'Every Night in my Dreams...'}"/>           

      </bean>

      <bean id="instrument1" class="com.lnn.spel.conditional.Instrument">

            <property name="name" value="#{song.getName() =='Jingle Bells...'? 'piano' : 'violin'}"/>

            <property name="song" ref="song"/>

      </bean>

      <bean id="instrument2" class="com.lnn.spel.conditional.Instrument">

            <property name="name" value="violin"/>

            <property name="song" value="#{song2}"/>

      </bean>

      <bean id="opera" class = "com.lnn.spel.conditional.Opera">

            <property name="instrument" value="#{song.name =='Every Night in my Dreams...'? instrument1 : instrument2}"/>      

      </bean>

</beans>

Test.java:

package com.lnn.spel.conditional;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

      public static void main(String[] args) {

            ApplicationContext context = new ClassPathXmlApplicationContext("conditional.xml");

            Opera opera = context.getBean("opera", Opera.class);

            System.out.println(opera.getInstrument().getName());

            System.out.println(opera.getInstrument().getSong().getName());

      }

}