如果属性类型是另外一个被装载的类，可以使用标签来装配属性值。
比如一个JavaBean中的某个属性是另外一个JavaBean的对象，而且要装备这个属性，那么就需要使用来标签ref进行装配。
MyBean类的hello属性是HelloService的类型，代码如下：
MyBean.java
- package chapter22;
- public class MyBean {
- private int iValue;
- private String strName;
- private HelloService hello;
- public int getiValue() {
- return iValue;
- }
- public void setiValue(int iValue) {
- this.iValue = iValue;
- }
- public String getStrName() {
- System.out.println("getStrName()方法被调用");
- return strName;
- }
- public void setStrName(String strName) {
- this.strName = strName;
- System.out.println("setStrName()方法被调用");
- }
- public HelloService getHello() {
- System.out.println("getHello()方法被调用");
- return hello;
- }
- public void setHello(HelloService hello) {
- this.hello = hello;
- System.out.println("setHello()方法被调用");
- }
- }
然后在applicationContext.xml中进行配置，配置如下：
- <?xml version="1.0" encoding="UTF-8" ?>
- <beans xmlns="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
- xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
- <bean id="helloservice" class="chapter22.HelloServiceImpl">
- <property name="greeting" value="greeting Xu Wei">
- </property>
- </bean>
- <bean id="myBean" class="chapter22.MyBean">
- <property name="hello">
- <ref bean="helloservice" />
- </property>
- <property name="strName" value="Xu Wei"></property>
- </bean>
- </beans>
TestMyBean.java
- package chapter22;
- import org.springframework.context.ApplicationContext;
- import org.springframework.context.support.FileSystemXmlApplicationContext;
- public class TestMyBean {
- public static void main(String args[]) {
- ApplicationContext ctx = new FileSystemXmlApplicationContext(
- "src//applicationContext.xml");
- MyBean mb = (MyBean) ctx.getBean("myBean");
- // System.out.println(mb.getHello());
- System.out.println(mb.getHello().getGreeting());
- System.out.println(mb.getStrName());
- }
- }
log4j:WARN No appenders could be found for logger (org.springframework.context.support.FileSystemXmlApplicationContext).
log4j:WARN Please initialize the log4j system properly.
setGreeting()方法被调用
setHello()方法被调用
setStrName()方法被调用
getHello()方法被调用
getGreeting()方法被调用
greeting Xu Wei
getStrName()方法被调用
Xu Wei
分析：
mb.getStrName是直接传参进去的，而这里通过ref穿进去的是hello，hello本身是一个对象，所以mb.getHello().getGreeting()获得的是hello配置的参数。
本文转自xwdreamer博客园博客，原文链接：http://www.cnblogs.com/xwdreamer/archive/2010/09/12/2297094.html，如需转载请自行联系原作者
