spring入门---------构造器注入

红太狼 2024-02-18 23:07 38阅读 0赞

## 使用构造器实现spring依赖注入 ##

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1.所需jar包

commons-logging-1.0.4.jar

spring.jar

2.实体类User.java

package entity;
    
    public class User {
    
    	private String name;
    	private Integer age;
    	private String sex;
    	//构造器注入
    	public User(String name, Integer age, String sex) {
    		
    		this.name = name;
    		this.age = age;
    		this.sex = sex;
    	}
    	//输出javabean的属性值方法
    	public void printInfo() {
    		System.out.println(name);
    		System.out.println(age);
    		System.out.println(sex);
    	}
    }

3.测试类Test.java

package main;
    
    import org.springframework.beans.factory.BeanFactory;
    import org.springframework.beans.factory.xml.XmlBeanFactory;
    import org.springframework.core.io.ClassPathResource;
    import org.springframework.core.io.Resource;
    
    import entity.User;
    
    public class Test {
    
    	public static void main(String[] args) {
    		// 导入配置文件
    		Resource resource=new ClassPathResource("applicationContext.xml");
    		//读取配置文件
    		BeanFactory factory=new XmlBeanFactory(resource);
    		//获取bean
    		User user=(User)factory.getBean("user");//通过bean名来获取bean
    		//调用printInfo方法
    		user.printInfo();
    		
    	}
    
    }

4.配置文件web.xml

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
      <display-name>springConstructor</display-name>
      <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
      </welcome-file-list>
    </web-app>

5.applicationContext.xml

<?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-2.5.xsd">
    	
    	<bean name="user" class="entity.User">
    		
    		
    		
    		 
    		 
    		<constructor-arg  index="0">
    			<value>小强</value>
    		</constructor-arg>
    		<constructor-arg  index="1">
    			<value>26</value>
    		</constructor-arg>
    		<constructor-arg  index="2">
    			<value>男</value>
    		</constructor-arg>
    	</bean>
    </beans>

6.运行效果

![70 1][]

[70]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/7c51b44400c04d4f9c32e06d8ead4027.png
[70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/7344806d64834525915147b2c0101dd6.png