在Spring EL，可以使用点(.)符号嵌套属性参考一个bean。例如，“bean.property_name”。
public class Customer {
@Value("#{addressBean.country}")
private String country;
在上面的代码片段，它从“addressBean” bean注入了“country”属性到现在的“customer”类的“country”属性的值。
Spring EL以注解的形式
请参阅下面的例子，演示如何使用使用 SpEL 引用一个bean，bean属性也它的方法。
package com.yiibai.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('yiibai')}")
private String fullAddress;
//getter and setter methods
@Override
public String toString() {
return "Customer [address=" + address + "\n, country=" + country
+ "\n, fullAddress=" + fullAddress + "]";
}
}
package com.yiibai.core;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component("addressBean")
public class Address {
@Value("GaoDeng, QiongShang")
private String street;
@Value("571100")
private int postcode;
@Value("CN")
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 + "]";
}
}
执行结果
Customer obj = (Customer) context.getBean("customerBean");
System.out.println(obj);
输出结果
Customer [address=Address [street=GaoDeng, QiongShang, postcode=571100, country=CN] , country=CN , fullAddress=yiibai : GaoDeng, QiongShang 571100 CN]
Spring EL以XML的形式
请参阅在XML文件定义bean的等效版本。
<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.yiibai.core.Customer">
<property name="address" value="#{addressBean}" />
<property name="country" value="#{addressBean.country}" />
<property name="fullAddress" value="#{addressBean.getFullAddress('yiibai')}" />
</bean>
<bean id="addressBean" class="com.yiibai.core.Address">
<property name="street" value="GaoDeng, QiongShang" />
<property name="postcode" value="571100" />
<property name="country" value="CN" />
</bean>
</beans>
