Collections: Wiring List with list(allow duplicates) and set(no duplicates)

Opera.java:

package com.lnn.collections;

import java.util.List;

public class Opera {

      private List<String> instruments;

      public void setInstruments(List<String> instruments) {

            this.instruments = instruments;

      }

      public void display() {

            for (String instrument : instruments) {

                  System.out.println(instrument);

            }

      }

}

collections.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="operaList" class="com.lnn.collections.Opera">

            <property name="instruments">

                  <list>

                        <value>Guitar</value>

                        <value>Piano</value>

                        <value>Piano</value>

                        <value>Violin</value>

                        <value>Violin</value>

                  </list>

            </property>

      </bean>

      <bean id="operaSet" class="com.lnn.collections.Opera">

            <property name="instruments">

                  <set>

                        <value>Guitar</value>

                        <value>Piano</value>

                        <value>Piano</value>

                        <value>Violin</value>

                        <value>Violin</value>

                  </set>

            </property>

      </bean>

</beans>

Test.java:

package com.lnn.collections;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

      public static void main(String[] args) {

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

            System.out.println("------------------List---------------------");

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

            operaList.display();

            System.out.println("------------------Set----------------------");

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

            operaSet.display();

      }

}