Bean的装配方式---XML---构造注入

User实体类

package com.student.assemble;

import java.util.List;

public class User {
	private String username;
	private Integer password;
	private List <String> list;
	//Source + Generate Constructor using Fields 自动生成构造方法
	public User(String username, Integer password, List<String> list) {
		super();
		this.username = username;
		this.password = password;
		this.list = list;
	}
	@Override
	public String toString() {
		return "User [username=" + username + ", password=" + password + ", list=" + list + "]";
	}
	
}

bean5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.xsd">

	<!-- services -->

	<bean id="user1" class="com.student.assemble.User">
		<constructor-arg index = "0" value = "tom"></constructor-arg>
		<constructor-arg index = "1" value = "123456"></constructor-arg>
		<constructor-arg index = "2" >
			<list>
				<value>"我爱你"</value>
				<value>"我也爱你"</value>
			</list>
		</constructor-arg>
	</bean>
</beans>

XmlBeanAssembleTest：测试类

package com.student.assemble;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.student.instance.constructor.Bean1;

public class XmlBeanAssembleTest {

	public static void main(String[] args) {
		String xmlPath = "com/student/assemble/bean5.xml";
		ApplicationContext applicationContext =new ClassPathXmlApplicationContext(xmlPath);
		User user =(User)applicationContext.getBean("user1");
		System.out.println(user);

	}

}

运行结果：

十月 13, 2019 6:15:06 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@46f7f36a: startup date [Sun Oct 13 18:15:06 CST 2019]; root of context hierarchy
十月 13, 2019 6:15:06 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/student/assemble/bean5.xml]
User [username=tom, password=123456, list=["我爱你", "我也爱你"]]

理解：测试类在实例化Bean的时候，配置文件的constructor-arg 会通过User的构造方法将User类的属性附上值（这个过程叫做为User装配）。