Spring5学习笔记3

用idea初学Spring5于哔哩哔哩狂神说java.留笔记便于以后查找.

此处重点有三：

1. 用构造函数赋值的bean
2. 起别名
3. 将所有的bean导入一个总表中.

1. 创建实体类

User.class

package com.chen.pojo;

public class User {
    private String name;
    
    public User(String name) {
        this.name = name;
    }
    
    public void show() {
        System.out.println("name=" + name);
    }
}

UserT.class

package com.chen.pojo;

public class UserT {
    private String name;

    public UserT(){
        System.out.println("UserT被創建了");
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void show() {
        System.out.println("name=" + name);
    }
}

2.创建Spring容器xml文件.

每个xml可以对应一个实体类,然后汇总到一个总的xml中使用.

applicationContext.xml

<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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
    
    <import resource="beans.xml"/>
    <import resource="beans1.xml"/>
    <import resource="beans2.xml"/>
beans>

beans.xml

<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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
    
    

    
    
    
    

    
    
    
    

    
    <bean id="user" class="com.chen.pojo.User">
        
        <constructor-arg name="name" value="秦寿"/>
    bean>

    
    <bean id="userT" class="com.chen.pojo.UserT" name="userT2 userT3">
        
        <property name="name" value="kuangstudy.com"/>
    bean>
beans>

beans1.xml

<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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

beans>

beans2.xml

<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
        https://www.springframework.org/schema/beans/spring-beans.xsd">

beans>

3.在test/java文件夹内创建MyTest.class进行测试

import com.chen.pojo.User;
import com.chen.pojo.UserT;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {
        //1.拿到容器
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        //2.用哪个对象get哪个对象
        User user =(User) context.getBean("user");
        user.show();
        System.out.println();

        UserT userT =(UserT) context.getBean("userT");
        userT.show();
        UserT userT2 =(UserT) context.getBean("userT2");
        userT2.show();
        UserT userT3 =(UserT) context.getBean("userT3");
        userT3.show();
    }
}