对于引用类型的属性，可以使用<property name="属性名" ref="×××" />进行初始化。如下图，ref="messager"，messager为另外定义的一个id为messager的bean。
<beans />标签内定义的带有id或者name属性的<bean />标签可以在Client代码中引用到进行使用。如果上图中定义的id 为messager的bean（第二个红框）的目的只是初始化messageLooper中的属性<property name="messager" />，而不想被Client代码访问，这时就可以使用inner bean去初始化<property name="messager" />。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" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> <bean id="messageLooper" class="demo.MessageLooper"> <property name="messager" > <!-- 以下bean的定义用来初始化property messager，注意以下定义的bean没有id和name属性，为inner bean--> <bean class="demo.GoodbyeMessagerImpl" /> </property> <property name="numTimes" value="3" /> </bean> </beans>
List类型属性的初始化：
<bean id="collectionTester" class="property.ListTester">
<property name="demoList" >
<list>
<value>entry1</value>
<value>entry2</value>
<value>entry3</value>
</list>
</property>
</bean>
也可以使用ref标签初始化列表内存放引用变量的的List
<bean id="collectionTester" class="property.ListTester">
<property name="demoList" >
<list>
<ref bean="类名"/>
</list>
</property>
</bean>
示例:
Set类型属性初始化：
<property name="demoList" >
<set>
<value>entry1</value>
<value>entry2</value>
<value>entry3</value>
</set>
</property>
Map类型属性初始化：
<property name=urlParamsMappingMap">
<map>
<entry key="businessOne">
<value>ACCOUNT=userid | TICKET=authid </value>
</entry>
<entry key="businessTwo">
<value>ACCOUNT=person_id | TICKET=pid </value>
</entry>
</map>
</property>
示例代码:
main运行类
package property;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class CollectionTesterMain
{
public static void main(String[] args)
{
String springConfig = "property/spring-config.xml";
ApplicationContext spring =
new ClassPathXmlApplicationContext(springConfig);
CollectionTester collectionTester =
spring.getBean("collectionTester", CollectionTester.class);
collectionTester.printCollection();
}
}
接口类
package property;
public interface CollectionTester
{
public void printCollection();
}
接口实现类
package property;
import java.util.List;
public class ListTester implements CollectionTester
{
private List<String> demoList;
public List<String> getDemoList()
{
return demoList;
}
public void setDemoList(List<String> demoList)
{
this.demoList = demoList;
}
@Override
public void printCollection()
{
if (demoList == null || demoList.size() == 0)
{
System.out.println("列表为空。");
}
else
{
for (String listEntry : demoList)
{
System.out.println(listEntry);
}
}
}
}
Spring配置文件
<?xml version="1.0" encoding="UTF-8"?>
<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="collectionTester" class="property.ListTester">
<property name="demoList" >
<list>
<value>entry1</value>
<value>entry2</value>
<value>entry3</value>
</list>
</property>
</bean>
</beans>