Spring集合 (List,Set,Map,Properties) 实例

Posted 2022-12-05 Wit_tang

下面例子向您展示Spring如何注入值到 集合类型(List, Set, Map, and Properties) 。 支持4个主要的集合类型：

• List – <list/>
• Set – <set/>
• Map – <map/>
• Properties – <props/>

Spring beans

一个Customer对象，有四个集合属性。

package com.yiibai.common;

import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

public class Customer 

	private List<Object> lists;
	private Set<Object> sets;
	private Map<Object, Object> maps;
	private Properties pros;
	
	//...

在bean配置文件中不同的代码片段用来声明集合。

1. List示例

<property name="lists">
		<list>
			<value>1</value>
			<ref bean="PersonBean" />
			<bean class="com.yiibai.common.Person">
				<property name="name" value="yiibaiList" />
				<property name="address" value="Hainan" />
				<property name="age" value="28" />
			</bean>
		</list>
	</property>

2. Set示例

<property name="sets">
		<set>
			<value>1</value>
			<ref bean="PersonBean" />
			<bean class="com.yiibai.common.Person">
				<property name="name" value="yiibaiSet" />
				<property name="address" value="Hainan" />
				<property name="age" value="28" />
			</bean>
		</set>
	</property>

3. Map示例

<property name="maps">
		<map>
			<entry key="Key 1" value="1" />
			<entry key="Key 2" value-ref="PersonBean" />
			<entry key="Key 3">
				<bean class="com.yiibai.common.Person">
					<property name="name" value="yiibaiMap" />
					<property name="address" value="Hainan" />
					<property name="age" value="28" />
				</bean>
			</entry>
		</map>
	</property>

4. Properties示例

<property name="pros">
		<props>
			<prop key="admin">[e-mail]</prop>
			<prop key="support">[e-mail]</prop>
		</props>
	</property>

Spring完整的 bean 配置文件。

<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.yiibai.common.Customer">

		<!-- java.util.List -->
		<property name="lists">
			<list>
				<value>1</value>
				<ref bean="PersonBean" />
				<bean class="com.yiibai.common.Person">
					<property name="name" value="yiibaiList" />
					<property name="address" value="Hainan Haikou" />
					<property name="age" value="28" />
				</bean>
			</list>
		</property>

		<!-- java.util.Set -->
		<property name="sets">
			<set>
				<value>1</value>
				<ref bean="PersonBean" />
				<bean class="com.yiibai.common.Person">
					<property name="name" value="yiibaiSet" />
					<property name="address" value="Hainan Haikou" />
					<property name="age" value="28" />
				</bean>
			</set>
		</property>

		<!-- java.util.Map -->
		<property name="maps">
			<map>
				<entry key="Key 1" value="1" />
				<entry key="Key 2" value-ref="PersonBean" />
				<entry key="Key 3">
					<bean class="com.yiibai.common.Person">
						<property name="name" value="yiibaiMap" />
						<property name="address" value="Hainan Haikou" />
						<property name="age" value="28" />
					</bean>
				</entry>
			</map>
		</property>

		<!-- java.util.Properties -->
		<property name="pros">
			<props>
				<prop key="admin">[e-mail]</prop>
				<prop key="support">[e-mail]</prop>
			</props>
		</property>

	</bean>

	<bean id="PersonBean" class="com.yiibai.common.Person">
		<property name="name" value="yiibai1" />
		<property name="address" value="Hainan Haikou 1" />
		<property name="age" value="28" />
	</bean>

</beans>

执行程序

package com.yiibai.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);
    	
    

输出

Customer [lists=[1, com.yiibai.common.Person@4e4ee70b, com.yiibai.common.Person@1e1867d2], sets=[1, com.yiibai.common.Person@4e4ee70b, com.yiibai.common.Person@52f644b4], maps=Key 1=1, Key 2=com.yiibai.common.Person@4e4ee70b, Key 3=com.yiibai.common.Person@54481b6d, pros=admin=[e-mail], support=[e-mail]]