SPEL : Selecting and Projecting Collections

.?[] to get sub collection
.^[] to get highest element
.$[] to get lowest element
.![] to get string collection

City.java:

package com.lnn.spel.collection;

public class City {

      private String name = null;

      private String state = null;

      private long population = 0;

      public String getState() {

            return state;

      }

      public void setState(String state) {

            this.state = state;

      }

      public long getPopulation() {

            return population;

      }

      public void setPopulation(long population) {

            this.population = population;

      }

      public String getName() {

            return name;

      }

      public void setName(String name) {

            this.name = name;

      }

}

Data.java:

package com.lnn.spel.collection;

import java.util.List;

public class Data {

      private List<City> bigCities;

      private City firstBigCity;

      private City lastBigCity;

      private List<String> cityNames;

      private List<String> cityStateNames;

      private List<String> condCityNames;

     

      public List<String> getCondCityNames() {

            return condCityNames;

      }

      public void setCondCityNames(List<String> condCityNames) {

            this.condCityNames = condCityNames;

      }

      public List<String> getCityNames() {

            return cityNames;

      }

      public void setCityNames(List<String> cityNames) {

            this.cityNames = cityNames;

      }

      public List<String> getCityStateNames() {

            return cityStateNames;

      }

      public void setCityStateNames(List<String> cityStateNames) {

            this.cityStateNames = cityStateNames;

      }

      public City getFirstBigCity() {

            return firstBigCity;

      }

      public void setFirstBigCity(City firstBigCity) {

            this.firstBigCity = firstBigCity;

      }

      public City getLastBigCity() {

            return lastBigCity;

      }

      public void setLastBigCity(City lastBigCity) {

            this.lastBigCity = lastBigCity;

      }

      public List<City> getBigCities() {

            return bigCities;

      }

      public void setBigCities(List<City> bigCities) {

            this.bigCities = bigCities;

      }    

}

cities.xml:

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

      xmlns:p="http://www.springframework.org/schema/p"

      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xmlns:util="http://www.springframework.org/schema/util"

      xsi:schemaLocation="  

      http://www.springframework.org/schema/beans

      http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

      http://www.springframework.org/schema/util

      http://www.springframework.org/schema/util/spring-util-3.0.xsd">

      <util:list id = "cities">

            <bean class="com.lnn.spel.collection.City" p:name="Chicago"

                  p:state="IL" p:population="2853114" />

            <bean class="com.lnn.spel.collection.City" p:name="Atlanta"

                  p:state="GA" p:population="537958" />

            <bean class="com.lnn.spel.collection.City" p:name="Dallas"

                  p:state="TX" p:population="1279910" />

            <bean class="com.lnn.spel.collection.City" p:name="Houston"

                  p:state="TX" p:population="2242193" />

            <bean class="com.lnn.spel.collection.City" p:name="Odessa"

                  p:state="TX" p:population="90943" />

            <bean class="com.lnn.spel.collection.City" p:name="ElPaso"

                  p:state="TX" p:population="613190" />

            <bean class="com.lnn.spel.collection.City" p:name="Jal" p:state="NM"

                  p:population="1996" />

            <bean class="com.lnn.spel.collection.City" p:name="LasCruces"

                  p:state="NM" p:population="91865" />

      </util:list>

      <bean id="data" class="com.lnn.spel.collection.Data">

            <property name="bigCities" value= "#{cities.?[population gt 100000]}"/>

            <property name="firstBigCity" value="#{cities.^[population gt 100000]}"/>

            <property name="lastBigCity" value="#{cities.$[population gt 100000]}"/>

            <property name="cityNames" value="#{cities.![name]}"/>

            <property name="cityStateNames" value="#{cities.![name+','+state]}"/>

            <property name="condCityNames" value="#{cities.?[population gt 100000].![name+','+state]}"/>

      </bean>

</beans>

Test.java:

package com.lnn.spel.collection;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

      public static void main(String[] args) {

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

            Data data = context.getBean("data", Data.class);

            for(City city : data.getBigCities()){

                  System.out.println(city.getName());

            }

            System.out.println(data.getFirstBigCity().getName());

            System.out.println(data.getLastBigCity().getName());

            for(String cityName : data.getCityNames()){

                  System.out.println(cityName);

            }

            for(String cityStateName : data.getCityStateNames()){

                  System.out.println(cityStateName);

            }

            for(String condCityName : data.getCondCityNames()){

                  System.out.println(condCityName);

            }

      }

}