ListFactoryBean”類為開發者提供了一種在Spring的bean配置檔中創建一個具體的列表集合類(ArrayList和LinkedList)。
這裏有一個 ListFactoryBean 示例,在運行時它將實例化一個ArrayList,並注入到一個 bean 屬性。
package com.xuhuhu.common; import java.util.List; public class Customer { private List lists; //... }
Spring bean配置檔 - applicationContext.html 檔的內容。
<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-2.5.xsd"> <bean id="CustomerBean" class="com.xuhuhu.common.Customer"> <property name="lists"> <bean class="org.springframework.beans.factory.config.ListFactoryBean"> <property name="targetListClass"> <value>java.util.ArrayList</value> </property> <property name="sourceList"> <list> <value>one</value> <value>2</value> <value>three</value> </list> </property> </bean> </property> </bean> </beans>
另外,還可以使用 util 模式和<util:list> 來達到同樣的目的。
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.5.xsd"> <bean id="CustomerBean" class="com.xuhuhu.common.Customer"> <property name="lists"> <util:list list-class="java.util.ArrayList"> <value>one</value> <value>2</value> <value>three</value> </util:list> </property> </bean> </beans>
請記住要包函 util 模式,否則會出現下麵的錯誤
Caused by: org.xml.sax.SAXParseException: The prefix "util" for element "util:list" is not bound.
執行,查看結果:
package com.xuhuhu.common; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class App { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext( "applicationContext.xml"); Customer cust = (Customer) context.getBean("CustomerBean"); System.out.println(cust); } }
輸出結果
Customer [lists=[one, 2, three]] Type=[class java.util.ArrayList]
在運行時實例化ArrayList並注入列表到客戶的屬性。