DI是Dependency Injection的缩写,依赖注入的意思,依赖了Spring容器,进行set注入,这里还是以一个例子进行阐述

首先我们创建两个实体类

package com.zhiying.pojo;

public class Address {
    private String address;

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "Address{" +
                "address='" + address + '\'' +
                '}';
    }
}
package com.zhiying.pojo;

import java.util.*;

public class Student {
    private String name;
    private Address address;
    private String[] books;
    private List<String> hobbies;
    private Map<String,String> card;
    private Set<String> games;
    private String wife;
    private Properties info;

    public String getName() {
        return name;
    }

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

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    public String[] getBooks() {
        return books;
    }

    public void setBooks(String[] books) {
        this.books = books;
    }

    public List<String> getHobbies() {
        return hobbies;
    }

    public void setHobbies(List<String> hobbies) {
        this.hobbies = hobbies;
    }

    public Map<String, String> getCard() {
        return card;
    }

    public void setCard(Map<String, String> card) {
        this.card = card;
    }

    public Set<String> getGames() {
        return games;
    }

    public void setGames(Set<String> games) {
        this.games = games;
    }

    public String getWife() {
        return wife;
    }

    public void setWife(String wife) {
        this.wife = wife;
    }

    public Properties getInfo() {
        return info;
    }

    public void setInfo(Properties info) {
        this.info = info;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", address=" + address.toString() +
                ", books=" + Arrays.toString(books) +
                ", \nhobbies=" + hobbies +
                ", card=" + card +
                ", games=" + games +
                ", \nwife='" + wife + '\'' +
                ", info=" + info +
                '}';
    }
}

然后是配置文件,核心

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

    <bean id="address" class="com.zhiying.pojo.Address"/>

    <bean id="student" class="com.zhiying.pojo.Student">
<!--    普通值注入-->
        <property name="name" value="贺志营"/>

<!--    Bean注入-->
        <property name="address" ref="address"/>

<!--        数组注入-->
        <property name="books">
            <array>
                <value>红楼梦</value>
                <value>西游记</value>
                <value>三国演义</value>
                <value>水浒传</value>
            </array>
        </property>

<!--        List注入-->
        <property name="hobbies">
            <list>
                <value>写代码</value>
                <value>听歌</value>
                <value>玩游戏</value>
            </list>
        </property>

<!--        Map注入-->
        <property name="card">
            <map>
                <entry key="姓名" value="贺志营"/>
                <entry key="性别" value="男"/>
            </map>
        </property>

<!--        Set注入-->
        <property name="games">
            <set>
                <value>王者荣耀</value>
                <value>英雄联盟</value>
            </set>
        </property>

<!--        null值注入-->
        <property name="wife">
            <null/>
        </property>

<!--        Properties注入-->
        <property name="info">
            <props>
                <prop key="username">root</prop>
                <prop key="password">123456</prop>
            </props>
        </property>
    </bean>


</beans>

然后就是测试了

import com.zhiying.pojo.Student;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyText {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        Student student = (Student) context.getBean("student");
        System.out.println(student.toString());
    }
}

Spring依赖注入DI_SpringBoot