Basic example using spEL Basic example using spEL

Step 1 :

Create a new package, com.simpleCodeStuffs.spEL€. Create the POJO classes Candidate.java and Address.java with the below specifications.
File : Candidate.java

package com.simpleCodeStuffs.spEL;
public class Candidate {

        private String name;
        private int age;
        private Address addrs;
        private String area;

        public String getArea() {
                return area;
        }

        public void setArea(String area) {
                this.area = area;
        }

        public Candidate() {
                this.name = null;
                this.age = 0;
                this.addrs = null;
        }

        public Candidate(String name, int age, Address addrs) {
                this.name = name;
                this.age = age;
                this.addrs = addrs;
        }

        public String getName() {
                return name;
        }

        public void setName(String name) {
                this.name = name;
        }

        public int getAge() {
                return age;
        }

        public void setAge(int age) {
                this.age = age;
        }

        public Address getAddrs() {
                return addrs;
        }

        public void setAddrs(Address addrs) {
                this.addrs = addrs;
        }
}

Fie : Address.java

package com.simpleCodeStuffs.spEL;
public class Address {

        private String doorNo;
        private String street;
        private String area;
        public Address() {
                this.doorNo = null;
                this.street = null;
                this.area = null;
        }

        public Address(String doorNo, String street, String area) {
                this.doorNo = doorNo;
                this.street = street;
                this.area = area;
        }

        public String getArea() {
                return area;
        }

        public void setArea(String area) {
                this.area = area;
        }

        public String getDoorNo() {
                return doorNo;
        }

        public void setDoorNo(String doorNo) {
                this.doorNo = doorNo;
        }

        public String getStreet() {
                return street;
        }

        public void setStreet(String street) {
                this.street = street;
        }
}

Step 2 :

Under the src folder, create a new xml file €“elBeans.xml to provide the configuration metadata using spEL
File ; elBeans.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="elAddress" class="com.simpleCodeStuffs.spEL.Address">
               <property name="doorNo" value="No. 10/7" />
              <property name="street" value="North Park Street" />
                <property name="area" value="Ambattur" />
        </bean>

      <bean id="elCandidate" class="com.simpleCodeStuffs.spEL.Candidate">
                <property name="name" value="Sandy" />
                <property name="age" value="22" />
                <property name="addrs" value="#{elAddress}" />
                <property name="area" value="#{elAddress.area}" />
        </bean>
</beans>

Note here, the value for the bean œelAddress€ is provided using a simple setter injection. But for the bean elCandidate , the value for addrs and area property is provided using spEL expression.
The general syntax for a spEL expression is

#{spEL Expression}

In the above example, the value for addrs is provided as #{elAddress}. This means that addrs is assigned the value set for the bean elAddress. Similarly, for area property, the value is assigned to #{elAddress.area}, thereby injecting the value of the ‘€˜area’ property from €˜’elAddress’€™ to the €˜area property inside elCandidate€™.

Step 3 : Provide the Main Class

File : MainClass.java

package com.simpleCodeStuffs.spEL;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainClass {

        public static void main(String[] args) {

                ApplicationContext context  

                     new ClassPathXmlApplicationContext("elBeans.xml");
              Candidate can = (Candidate) context.getBean("elCandidate");
                Address add = (Address) context.getBean("elAddress")
                System.out.println("Name: " + can.getName());
                System.out.println("Age  : " + can.getAge());
                System.out.println("Area  : " + can.getArea());
             System.out.println("Address : " + can.getAddrs().getDoorNo());
                System.out.println("t " + add.getStreet());
                System.out.println("t  " + add.getArea());
        }
}