1、spring的IOC

完整代码：spring1.zip - 蓝奏云

将对象的创建权交给spring框架，我们再使用new创建对象。

我们使用idea和maven进行编译开发

1、导入spring相关的包

 <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.3.12</version>
 </dependency>

2、定义个Category类

package com.how2j.pojo;

public class Category {

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "Category{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    private int id;
    private String name;
}

3、编写xml文件，设置java bean，

<?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">


    <bean name="c" class="com.how2j.pojo.Category">
        <property name="id" value="1"/>
        <property name="name" value="category 1"/>

    </bean>
</beans>

4、测试spring

package test;
import com.how2j.pojo.Category;
import org.junit.jupiter.api.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestSpring {

    @Test
    //spring的控制翻转
    public void test1(){
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml" );

        Category c = (Category) context.getBean("c");

        System.out.println(c);
    }
}

注：目录结构如下：