SpringIoc的发展经历了三种方式：

• 1.通过new的方式创建
• 2.通过工厂模式获取不同的实例对象（需要自己写工厂）
• 3.通过ioc容器获取不同的实例对象（只需要自己配置即可）

1、目录结构

目录结构.png

1.1 pom.xml

 <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

1.2 User实体类

package com.spring;
/**
 * @Classname User
 * @Description TODO 用户实体类
 * @Date 2019/12/13 10:31 下午
 * @Created by wangxianlin
 */
public class User {

    private String id;
    private String name;
    private String address;
    public void useCreateMethod(String name){
        System.out.println("使用"+name+"方式创建对象");
    }
    public String getId() {
        return id;
    }
    @Override
    public String toString() {
        return "User{" +
                "id='" + id + '\'' +
                ", name='" + name + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

1.3 CreteUserFactory

public class CreteUserFactory {
    public static User getUser(){
        return new User();
    }
}

1.4 bean.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-3.0.xsd">

    <bean id="User" class="com.spring.User"/>
</beans>

2、创建方式

2.1 传统的new方式

  /***
     * @Author wangxl
     * @Description //TODO 通过new方式创建对象
     * @Date 11:33 下午 2019/12/13
     * @Param []
     * @return void
     **/
    @Test
    public void TestUser2(){
        User user = new User();
        user.setAddress("安徽省合肥市");
        user.setId("1238784");
        user.setName("HeloWxl");
        System.out.println(user.toString());
        user.useCreateMethod("new");
    }

new.png

2.2 通过工厂创建

    @Test
    public void TestUser3(){
        User user = CreteUserFactory.getUser();
        user.setAddress("安徽省合肥市");
        user.setId("1238784");
        user.setName("HeloWxl");
        System.out.println(user.toString());
        user.useCreateMethod("factory");
    }

factory.png

2.3 通过IOC创建

    @Test
    public void TestUser(){
        //从spring容器获得 //1 获得容器
        String xmlPath="bean.xml";
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
        //2获得内容 --不需要自己new，都是从spring容器获得
        User user = (User) applicationContext.getBean("User");
        user.setAddress("安徽省合肥市");
        user.setId("1238784");
        user.setName("HeloWxl");
        System.out.println(user.toString());
        user.useCreateMethod("ioc");
    }

ioc.png