How to Initialize List, Map,Set and Properties in Spring ?

Let's take an example to understand how to Initialize list in spring.

DrawingApp.java

public class DrawingApp {

    public static void main(String[] args) {

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

        Triangle triangle = (Triangle) context.getBean("triangle");

        triangle.draw();

    }

}

Triangle.java

public class Triangle {

    private List<Point> points;

    public List<Point> getPoints() {

        return points;

    }

    public void setPoints(List<Point> points) {

        this.points = points;

    }

  public void draw(){

        System.out.println("Points are ");

        for(Point point : points){

            System.out.println("("+point.getX()+","+point.getY()+")" );

        }

    }

} 

Point.java
 

public class Point {
    private int x;
    private int y;
   
    public int getX() {
        return x;
    }
    public void setX(int x) {
        this.x = x;
    }
    public int getY() {
        return y;
    }
    public void setY(int y) {
        this.y = y;
    }
   
}

spring.xml

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

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>

    <bean id="triangle" class="com.example4.Triangle">

        <property name="points">

            <list>

                <ref bean="zeroPoint" />

                <ref bean="point2" />

                <ref bean="point3" />

            </list>

        </property>

    </bean>

    <bean id="zeroPoint" class="com.example4.Point">

        <property name="x" value="0"/>

        <property name="y" value="0"/>

    </bean>

    <bean id="point2" class="com.example4.Point">

        <property name="x" value="-20"/>

        <property name="y" value="0"/>

    </bean>

    <bean id="point3" class="com.example4.Point">

        <property name="x" value="20"/>

        <property name="y" value="0"/>

    </bean>

</beans>

Output :    Points are

                 (0,0)

                 (-20,0)

                 (20,0)

If you want to Initialize MAP then you have to write like this in spring.xml

  <property name="points">

        <map>

            <entry key="Key 1" value="zeroPoint" />

            <entry key="Key 2" value-ref="point2" />

            <entry key="Key 3">

                <bean class="com.example4.Point">

                    <property name="x" value="0" />

                    <property name="y" value="0" />

                </bean>

            </entry>

        </map>

    </property>

If you want to Initialize SET then you have to write like this in spring.xml

 

 <property name= "points">    

      <set>

             <value>1</value>
             <ref bean="zeroPoint" />
             <bean class="com.example4.Point">
                   <property name="x" value="0" />
                   <property name="y" value="10" />
             </bean>
             <ref bean="point3" />

      </set>

</property>




If you want to Initialize Properties then you have to write like this in spring.xml

<property name="pros">

        <props>

            <prop key="admin">admin@motionwelder.com</prop>

            <prop key="support">support@motionwelder.com</prop>

        </props>

    </property>