Spring EL bean引用实例 - Spring教程

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>

下载代码 – http://pan.baidu.com/s/1pJTgLUN