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_ide