Spring EL method invocation example

In Spring EL, you can reference a bean, and nested properties using a ‘dot (.)‘ symbol. For example, “bean.property_name“.

public class Customer {
	
	@Value("#{addressBean.country}")
	private String country;

In above code snippet, it inject the value of “country” property from “addressBean” bean into current “customer” class, “country” property.

Spring EL in Annotation

See following example, show you how to use SpEL to reference a bean, bean property and also it’s method.

package com.mkyong.core;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component("customerBean")
public class Customer {

	@Value("#{addressBean}")
	private Address address;

	@Value("#{addressBean.country}")
	private String country;
	
	@Value("#{addressBean.getFullAddress('mkyong')}")
	private String fullAddress;

	//getter and setter methods
	
	@Override
	public String toString() {
		return "Customer [address=" + address + "
, country=" + country
				+ "
, fullAddress=" + fullAddress + "]";
	}

}

package com.mkyong.core;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component("addressBean")
public class Address {

	@Value("Block ABC, LakeView")
	private String street;

	@Value("98700")
	private int postcode;

	@Value("US")
	private String country;

	public String getFullAddress(String prefix) {

		return prefix + " : " + street + " " + postcode + " " + country;
	}

	//getter and setter methods

	public void setCountry(String country) {
		this.country = country;
	}

	@Override
	public String toString() {
		return "Address [street=" + street + ", postcode=" + postcode
				+ ", country=" + country + "]";
	}

}

连私有属性都可以直接访问

Run it

       Customer obj = (Customer) context.getBean("customerBean");
       System.out.println(obj);

Output

Customer [address=Address [street=Block ABC, LakeView, postcode=98700, country=US]
, country=US
, fullAddress=mkyong : Block ABC, LakeView 98700 US]

Spring EL in XML

See equivalent version in bean definition XML file.

<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="customerBean" class="com.mkyong.core.Customer">
		<property name="address" value="#{addressBean}" />
		<property name="country" value="#{addressBean.country}" />
		<property name="fullAddress" value="#{addressBean.getFullAddress('mkyong')}" />
	</bean>

	<bean id="addressBean" class="com.mkyong.core.Address">
		<property name="street" value="Block ABC, LakeView" />
		<property name="postcode" value="98700" />
		<property name="country" value="US" />
	</bean>

</beans>